29th SSSEA Conference of the Soil Science Society of East Africa (SSSEA) held at the Lake Naivasha Lodge,

Naivasha, Kenya18th -22nd November 2019

Climate Smart Land and Water Management Innovations for Enhanced Food and Nutrition Security

Book of Abstracts

Programme&

The Soil Science Society of East Africa (SSSEA)

DisclaimerThe views expressed herein are those of the authors and not the Soil Science Society of East Africa.

Published by the Soil Science Society of East Africa (SSSEA)

The Soil Science Society of East Africa (SSSEA)

Book of Abstracts

Programme&

Climate Smart Land and Water Management Innovations for Enhanced Food and Nutrition Security

29th SSSEA Conference of the Soil Science Society of East Africa (SSSEA) held at the Lake Naivasha Lodge,

Naivasha, Kenya18th -22nd November 2019

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Book of Absstracts

Provisional ProgrammeDAY 1: Sunday 17 November 2019 Travel to Naivasha DAY 2: Monday 18 November 2019

Time Event8:30-9:00am Registration of participantsSession 1:Theme 1: Enhancing applications of land and water technologies, innovations and management practices (TIMPs) for adaptation and mitigation to climate variability and changeChairperson: Dr Patrick GicheruRapporteur: Dr Mary Koech 9:00 – 9:30am Key Note Address: Agronomic bio-fortification: productivity,

profitability and plant quality effects in Sub-Saharan Africa. Dr Job Kihara - CIAT

PARALLEL SESSION 1A: THEME 1

9:30 – 9:40am Appropriate cropping pattern for improved land productivity on terraced Andosol in Suswa, Narok County. Alice Ruto, Charles Gachene, Patrick Gicheru, David Mburu and Zainabi Khalif.

9:40 – 9:50am Spatial variability in soil properties and plant nutrients of paddy rice of Mwea, Kenya. Kundu C. A., T. Masunaga, K. Sato, M. Ishii, A.Yamauchi, D. Makihara and R. K. Wanjogu.

9:50 – 10:00am Prediction of infiltration rates of fallow and cultivated soils in Minna, Southern Guinea Savanna Zone of Nigeria. Eze, P. C. and Musa, J.J.

10:00 – 10:30am HEALTH BREAK10:30 – 10:40am Using AQUACROP to compare climate change strategies for maize

production in a Kenyan Humic Nitisol. Onyango J. W., J.M. Miriti and A.O. Esilaba.

11:40 – 11:50pm Changes of soil conditions and maize yield after years of conventional or reduced tillage on a Mollic Andosol. Mwangi, H.G., Irene, W.G., Ooro, P.A., Esilaba A. O., Githunguri, C. and Lusike, W.

11:50 – 12:00pm Anthill soil utilization in maize cropping systems: an endogenous soil fertility management practice by smallholder farmers in Zambia -Kafula Chisanga, Ernest R. Mbega, Patrick A. Ndakidemi

12:00 – 12:10pm The contribution of plastic tube digester (PTD) innovations in climate change mitigation and improved rural livelihoods: Case study of central Kenya. Francis M. Matiri, E.M Kiruiro and S.C. Amboga.

12:10 – 12:20pm On-station and On-farm Testing of Best Bet Bean Technologies, Innovations and Management Practices in Nandi and Trans Nzoia Counties. Barkutwo, J Kifuko-Koech, M.N., K.W. Ndungu-Magiroi, M. Mutoko, M. Kamidi, J. Wanyama,E. Wanjekeche, V.Ouma, A.O. Esilaba J.M. Miriti, D. Nyongesa, C. Githunguri, E.G. Thuranira, M.O. Okoti, and L. Wasilwa.

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12:20 – 12:30pm Performance of cereals and pulses under conservation agriculture technologies in coastal Kenya. Pole F.N., Muthiani E., Njunie M.N., Kiptoo R., Maingu R.A., Munyambu P., Changasi R., Muli B.M., Ondiko C., Chivatsi W.S., Kengo D., Mzingirwa A., Esilaba A., Nyongesa D., Thuranira E.G., Angela K., Okoti M.O., and Wasilwa L.A.

12:30 – 1:00 pm Plenary Discussions

THEME 1: PARALLEL SESSION 1B:Chairperson: Dr. D. KamauRapporteur: Dr K. Ndungu-Magiroi 9:30 – 9:40am Variations in plant nutrient allocation, physiological development

patterns and soil structural characteristics as influenced by zero tillage systems: perspectives from short-term trials in sub-humid region in the central highlands of Kenya. Kinyua M., Mucheru-Muna, M., Kihara, J.

9:40 – 9:50am Assessing the contribution of climate smart agriculture practices on the resilience of maize farmers in Bungoma County, Kenya. Siminyu P.,Oluoch-Kosura W., De Groote H., Mbau J. S.

9:50 – 10:00am Physical and hydraulic characterization of soils for the design of the infield water use system for improved irrigation efficiency in lower Nzoia. Muya, E.M., M. Masaku, I.V. Sijali, L. T. Chirchir and H. Rotich

10:00 – 10:30am HEALTH BREAK10:30 – 10:40am Effect of tillage, cropping systems and fertilizers application on

Green gram (Vignaradiata L.) biomass and grain yields in semi-arid Kenya. Njiru, E., Macharia, D., Mutisya, D, Esilaba, A. O. Nyongesa, D.,Ndanu, A., Thuranira, E., Okoti, M. and Nguluu, S.

10:40 – 10:50am Residue management and tillage practices interactions on crop productivity in semi-arid areas of Embu and Tharaka-nithi counties. Micheni A., Njagi I., Esilaba A., Kinuthia P., Thuranira E, Gicheru P., Nyongesa D., Nthiga M. & Muriithi S.

10:40 – 10:50am Using Conservation Agriculture to Conserve Soil Moisture for Enhanced maize Production and Improved Soil Properties in the semi-Arid Machakos County, Kenya. Gitari J. N., Waweru P. K., Kuria P., Mkomwa S. and Onyari C. N.

10:50 – 11:00am Soil Organic Carbon dynamics from Conservation Agriculture practices in the Ferralsols of Western Kenya and Eastern Uganda. Oluko, P.S., J.R. Okalebo, P.O. Kisinyo, J. Norton, W. N’getich, J. W. Wangoli

11:00 – 11:10am Strategies and Technologies for Watershed Management: The Case of Kibuon and Tende rivers Catchment in South West Kenya. Mwangi, T.J.K., Nelson L. Kidula, Aloys R. Ondicho, Dymphina K. Andima, Maurice C. Shiluli, Richard K. Kanda and Lawrence Tong’i.

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11:00 – 11:10am Analysis of soil potential for sustainable land use planning for the third crop in Bunyala Scheme E.M. Muya, I.V. Sijali, M. Masaku, N. Korir, M. Otipa, H. Rotich, A.L Chek and C. Ngige.

11:10 – 11:20am Biophysical production potential and zonation of Taita Taveta research sites for enhanced water and fertilizer use efficiency. E.M. Muya, L.K. Tanui, I.V. Sijali, P. Kathuli, A.O. Esilaba, J. Miriti, D. Nyongesa, A.L.Chek, E. Thuranira and C. Githunguri.

11:20 – 11:30am Exploring the potential of using Fallout radio nuclides (Caesium – 137) to measure soil erosion and deposition rates in Uganda Nansamba, A., Kaizzi, C.K., Byalebeka, and J.B.

11:30 – 11:40am Innovative approach of predicting soil properties in the eastern slopes of Mount Kenya. Mutuma Evans, Csorba Adam, Michéli Erika.

11:40 – 11:50am Macro and micro-nutrient status of some Kenya soils. J. A. Omwakwe, Prof George N. Chemining’wa, Dr. A.O. Esilaba, EG Thuraniraa.

11:50 – 12:00am Participatory appraisal of integrated Vertisol management options for enhancing food security and income generation for Arid and Semi-Arid Lands in Kenya. Joab Onyango Wamari, J.N.K Macharia, I.V. Sijali.

12:00 – 12:10am Planning for Land Degradation Neutrality in Nalwekomba catchment, Kamuli district Uganda. Isabirye, M. Stephen Muwaya, Mathias Magunda.

12:10 – 12:20am Soil erosion and deposition rates determined using Fallout radionuclides (Caesium – 137) in eastern and south western Highland of Uganda. Kaizzi C.K., Byalebeka J.B., and Nansamba A.

12:20 – 12:30am Spatial Variability in Soil Properties and Plant Nutrient of Paddy Rice in Mwea, Kenya. Kundu C. A., T. Masunaga, K. Sato, M. Ishii, A.Yamauchi, D. Makihara and R. K. Wanjogu.

12:30 – 1:00 pm Plenary Discussions 1:00 – 2:00pm LUNCH BREAK THEME 1: PARALLEL SESSION 2A:Chairperson: Dr. N. Mangale Rapporteur : Dr. Ligeyo2:00 – 2:10 pm Spatial Vulnerability Assessment of River Mitano Catchment to

Degradation in SW Uganda-Congo Boarder. Musinguzi, P., B. Barasa, John Kameri, B. Atukwase, E. Elizabeth Aisu; S. Ogwete; S. Opio; W. Epalitai; J.Okot-Okum.

2:10 – 2:20 pm Clustering soils for precision agriculture and enhanced crop yield response to water and fertilizer in Machakos County. E.M. Muya, I.V. Sijali, J.M. Mirit, L. T. Chirchir, P.N. Macharia, A.O. Esilaba, E.G. Thuranira H. Rotich, D. Nyongesa and C.W. Githunguri.

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2:20 – 2:30 pm Effects of blended NPK fertilizer sources and rates on growth and yield of maize in Kirinyaga County, central Kenya. P.W. Mwangi, J.M. Miriti and E.M. Muriuki

2:30 – 2:40 pm Physical and hydraulic characterization of soils for the design of the infield water use system for improved irrigation efficiency in Lower Nzoia. E.M. Muya, M. Masaku, I.V. Sijali, L. T. Chirchir and H. Rotich

2:40 – 2:50 pm Prospects of using Integrated Soil Fertility Management practices for improved soil productivity and food security in Machakos County. S. W. Wamalwa, Danga,B. and Kwena, K.

2:50 – 3:00 pm Performance of maize hybrids under contrasting crop management Strategies in Nakuru County. Ooro, P.A., Mwangi, H.G., Esilaba, A.O., Nyongesa, D., Miriti, J.M. Okoti, M., Lusike, W.A., Githunguri, C., Thuranira, E.G., Moraa, L.M., Luvonga, J., Osoo, J.O. and Bor, P.K.

3:00 – 3:10 pm Performance of open pollinated maize varieties under low nitrogen conditions in highland and transitional ecologies of Kenya. Ligeyo D.O.,Saina E, Awalla B. J., Wanyama J. M and Woyengo V. W.

3:10 – 3:20 pm Potassium based fertilizer on green grams and millet yields in Embu and Tharaka-Nithi counties. Micheni A., Kinuthia P., Njagi I., Esilaba A., Muriithi S., Thuranira E., Gicheru P. and Nyongesa D.

3:20 – 3:30 pm Potassium essential nutrient status and management in Kenyan soils for increased productivity. Kathuku-Gitonga A. N., A.O. Esilaba, N. Mangale,L. Wasilwa, M. Okoti, D. Nyongesa, C. Githunguri, J.M. Miriti, E. Thuranira, G. Ashiono, Woyengo V., Ooro, P.A., H.G, Mwangi, M.N. Kifuko-Koech, K.W. Ndungu-Magiroi, Kimani S. K., Gikonyo E. W., Mbuthia L., Kamau D., Kibunja C. N., M. Njunie, B. M. Muli, E. Muthiani, D. Mutisya, D. R. Macharia and C. Nekesa.

3:30 – 3:40 pm Demonstrating effect of using DAP and Mavuno fertilizers on groundnuts pod and pop yield in western Kenya. Rachier G.O, I. Njaro, F. Wayua and D. Chengo

3:40 – 3:50 pm Effect of nitrogen sources on nitrous oxide emission, nitrogen use efficiency and maize yield in western Kenya. Peter Asbon Opala, David Masi Kamusuya, Harun Ogindo

3:50 – 4:00 pm Determining effect of different integrated soil fertility management on capsicum (Capsicum anuum) under controlled environmental condition. C.H. Morit, F. L. Mkandawire, O.H. Moracha, S.K Kimani, P.N.M. Njeru, I Sijali and J. Gacheru.

4:00 – 4: 30 pm HEALTH BREAK 4:30 – 4:40 pm Different potash fertilizers increase maize yields in Trans Nzoia and

Bungoma Counties in Western Kenya. S.K. Kimani, Gikonyo, E.W. C.N. Kibunja, A.O. Esilaba, D.M. Kamau, P.N.M. Njeru and L.W. Mbuthia.

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Book of Absstracts

4:40 – 4:50 pm Effect of DAP, mixture of goat and poultry manure on growth and yields of green grams (VignaRadiata L.) in Embu County, Kenya. Nyapola Andulu Carolyne, Johnson Kwach, Jayne N.Mugwe.

4:50 – 5:00 pm Selection Process of Performing Integrated Soil Fertility Management (ISFM) Technologies for Enhanced Maize Production in Kenya. Mangale, N., Kathuku-GitongaA.N., MuriukiA.W. and Mutegi J.K.

5:00 – 5:10 pm Effect of different potassium fertilizer rates and liming on recommended maize yield grown in western Kenya. Cyrus M Githunguri, Joseph M Miriti, Elias G Thuranira, Mary N Koech, Keziah W Ndungu, Vincent W Woyengo, Gerald Ashiono.

THEME 1: PARALLEL SESSION 2B:Chairperson: Dr. A. Micheni Rapporteur : Dr. J. Wanyama 2:00 – 2:10 pm Strong spatial-temporal patterns in maize yield response to nutrient

additions in Western Kenya - Samuel Njoroge, Antonius G.T. Schut, Ken E. Giller, Shamie Zingore, Joses Muthamia

2:10 – 2:20 pm Sulphur Nutrition in Crop Production Research in Kenyan: A Review. Mangale, N., Esilaba, A.O, Kathuku-Gitonga A. N.Nyongesa, D. and Wasilwa, L.

2:20 – 2:30 pm Value addition and use of integrated soil fertility management (ISFM) technologies to Enhance production of soybean (SB 19) in Eastern Kenya- Peterson N. M. Njeru, Stephen. K. Kimani, Violet O. Kirigua and David K. Lelgut

2:30 – 2:40 pm Yield Response of Finger Millet to Poultry Manure application in Western Kenya- Makete, N. N., Oduori, C.A., Opole, R.A., Mulindo, C.J., and Nungo, R.A.

2:40 – 2:50 pm Potassium Fertilizer Recommendation Rate for Economic Rice Production at Mwea Irrigation scheme – Kenya. Gikonyo, E.W., Kimani, S.K., Gichangi A., Kibunja, C.N., Esilaba, A.O., Mbuthia, L.W. and Kega, V.M

2:50 – 3:00 pm Evaluation of the effects of goat manure-based Vermi-compost on soil chemical properties under garlic production in eastern Kenya. Gichaba, V.M, Ndukhu, H.O, Muraya, M, Odilla, G.A

3:00 – 3:10 pm Trends in soil science research in Kenya for the last 90 years – The missing gaps. Esther Uchi Mumba and Charles, K.K.

3:10 – 3:20 pm Effect of different soil enhancements on maize grain yield and its parameters in central highlands of Kenya for improved productivity. Catherine Muriithi, Miriam Nyokabi and Kellen Kagendo

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3:20 – 3:30 pm Effect of fertilizer on yield performance and stability on popular maize varieties in mid-late agro-zone of western Kenya. Woyengo VW., Ashiono G., Odendo M., Onyango E., Esilaba A. O., Nyongesa D. W., Githunguri C.M., Thuranira E. G., Miriti J. M., Okoti M.O. and Lusike, W.

3:30 – 3:40 pm Effect of fertilizer rates and variety on bean (Phaseolus vulgaris L.) grain yields in different counties of western Kenya. C. M. Githunguri, A.O. Esilaba, M. Okoti, J. Miriti, D. Nyongesa, E. Thuranira, M. Koech, C. Mutoko, K. Ndungu, P. Ooro, P. Ketiem, H. Mwangi, V. Woyengo, M. Odendo, and G. Ashiono.

3:40 – 3:50 pm Effect of integrated soil water and fertility management in maize-bean cropping system in western Kenya. Ashiono, G.B., Woyengo, V., Esilaba, A.O. and Wasilwa, L

3:50 – 4:00 pm Macro and micro-nutrients status. J.A. Omwakwe, George, N. Chemining’wa, A.O. Esilaba and E. Thuranira.

4:00 – 4: 30 pm HEALTH BREAK 4:30 – 4:40 pm 4:40 – 4:50 pm 4:50 – 5:00 pm 5:00 – 5:10 pm 5:10 – 6:10 pm PLENARY DISCUSSION

END OF DAY TWODAY 3: Tuesday 19 November 2019Session 2: OPENING CEREMONYChairperson: Dr. Mary Koech Rapporteur: Dr. R. Emong’or 8:00 – 8:10 am Effect of different soil enhancements on maize grain yield and its

parameters in central highlands of Kenya for improved productivity. Catherine Muriithi, Miriam Nyokabi and Kellen Kagendo

8:10 – 8:20 am Effect of fertilizer on yield performance and stability on popular maize varieties in mid-late agro-zone of western Kenya. Woyengo VW., Ashiono G., Odendo M., Onyango E., Esilaba A. O., Nyongesa D. W., Githunguri C.M., Thuranira E. G., Miriti J. M., Okoti M.O. and Lusike, W.

8.20 – 8.30 am Effect of fertilizer rates and variety on bean (Phaseolus vulgaris L.) grain yields in different counties of western Kenya. C. M. Githunguri, A.O. Esilaba, M. Okoti, J. Miriti, D. Nyongesa, E. Thuranira, M. Koech, C. Mutoko, K. Ndungu, P. Ooro, P. Ketiem, H. Mwangi, V. Woyengo, M. Odendo, and G. Ashiono.

8:30 – 8:40 am Effect of integrated soil water and fertility management in maize-bean cropping system in western Kenya. Ashiono, G.B., Woyengo, V., Esilaba, A.O. and Wasilwa, L

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Book of Absstracts

8:40 – 8:50 am Macro and micro-nutrients status. J.A. Omwakwe, George, N. Chemining’wa, A.O. Esilaba and E. Thuranira.

8:50 – 9:00 am Effects of cattle manure on growth and yield of tomato (solanum lycopersicum) under greenhouse condition in UasinGishu County. C. Gloria, P.N. M. Njeru and S.K. Kimani

9.00 – 9:10am Effects of nitrogen application times on performance of improved sugarcane varieties for plant crop cycle under Cambisols of Kibos, Kenya. Omollo Jacob Omondi.

9:10 – 9:20 am Efficacy of common basal fertilizers on maize production in Nandi and Trans Nzoia Counties. Ndung’u-Magiroi, K.W., Kifuko. M.N., Mutoko, C.M., Wanjekeche, E., Kamidi, M.Barkutwo, J.Wanyama, J.M., J.M. Miriti, D. Nyongesa, C. Githunguri, E.G. Thuranira, M.O. Okoti, L. Wasilwa and A.O. Esilaba

9:20 – 9:30 am Evaluating the effects of a formulated slow release nano-composite NPK fertilizer on growth and yield of maize, kale and capsicum. Kiplangat Rop, George N. Karuku, Damaris Mbui, NjagiNjomo, Immaculate Michira.

9:30 – 10:00 am Plenary Discussion10:00 – 10:30 am HEALTH BREAK Chairperson: Dr E. Kireger, Director General, KALRORapporteur: Dr Stephen Kimani, SSSEA, Secretary - Kenya Chapter10:30 – 10.40 am Introduction/ Opening remarks: Director General, Kenya

Agricultural and Livestock Research Organization (KALRO)10:40 – 10.50 am Representative from Fertilizer Industry- Eustace Muriuki-FAK10:50 – 11.00 pm Kenya Markets Trust – Representative Charles Warria 11:00 – 11.10 pm Governor, Nakuru County11:10 – 11.20 am Guest of Honour: Principal Secretary, State Department of Crop

Development and Agriculture Research, MoALF11:20 – 11.30 am Setting the Scene: Balanced plant fertilization and good agricultural

practices to support Africa’s agricultural transformationDr. R. Harawa et al AGRA

11.30 – 12.00pm Keynote Address: Balanced crop fertilization and soil organic matter management are key to sustained high yields of common food crops in Kenya. J. Mutegi ,A. Kiwia J. Macharia, R. Harawa & J. Muthamia

12:00 – 1:00 pm PANEL DISCUSSION/MEDIA BRIEFING 1:00 – 2:00 pm LUNCH BREAKPARALLEL SESSION 1A: THEME 2 Theme 2: Balanced plant fertilization and good agricultural practices for improving soil fertility, crop productivity and profitabilityChairperson: Kaizzi KayukiRapporteur: E. Gikonyo

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2:00 – 2:10 pm Evaluation of different fertilizer application techniques on the growth and leaf yield of nightshade under greenhouse condition in Baringo County. G. Kigen, P.N.M. Njeru, S. S. Kimani and I. Sijali.

2:10 – 2:20 pm Formulation of slow release nano-composite NPK fertilizer using biodegradable polymer hydrogel and evaluating the release of nutrients. Kiplangat Rop, George N. Karuku, Damaris Mbui, Immaculate Michira, NjagiNjomo

2:20 – 2:30 pm Maize hybrid response to rates and timing of basal phosphate application in an acidic Ferralsol of North Rift Kenya. Ndung’u-Magiroi, K.W. and Kifuko-Koech, M.N

2:30 – 2:40 pm On-station and on-farm testing of Integrated Soil Fertility Management strategies and conservation tillage practices in western Kenya. Kifuko-Koech, M.N., K.W.Ndungu-Magiroi, M. Mutoko, M. Kamidi, J. Barkutwo, J. Wanyama, E. Wanjekeche, V.Ouma, A.O. Esilaba, J.M. Miriti, D. Nyongesa, C. Githunguri, E.G. Thuranira, M.O. Okoti and L Wasilwa.

2:40 – 2:50 pm Effects of Tunza organic bio -fertilizer on maize crop yields, soil nutrients and microbial dynamics. Irambu E.M., Kibunja C.N, Thuranira. E.G and Mary W. Gateri

2:50 – 3:00 pm Overcoming soil acidity constraints through liming and other soil amendments in Kenya. A review. A.O. Esilaba, N. Mangale, A. N. Kathuku-Gitonga, D. M. Kamau, A. W. Muriuki, D. Mbakaya and S. Zingore.

3:00 – 3:10 pm Participatory on-farm trials providing soil fertility information on raising maize yield in semi-arid eastern Kenya. C. M. Githunguri, A. O. Esilaba, S. Zingore, and C. Kibunja

3:10 – 3:20 pm Potassium response in maize at Bungoma and Trans-Nzoia counties in western Kenya. S.K. Kimani, Gikonyo, E.W., C.N. Kibunja, A.O. Esilaba, Kamau, D.M. and L.W. Mbuthia.

3 20 – 345 pm Discussion 3:45 – 4:15 pm Health Break 4:15 – 4:25 pm The potential of intercropping for increased income, food and

nutrition in KASALs. A. N. Kathuku-Gitonga, A.O. Esilaba, N. Mangale, L. Wasilwa, M. Okoti, D. Nyongesa, P.T. Kamoni, B. K. Waruru, E.M. Muya, E. Thuranira, D. Mutisya, D. R. Macharia

4:25 – 4:35 pm Tillage, residue management and cropping systems affect soil aggregation, organic carbon and microbial biomass in tropical Ferralsols of western Kenya. Peter Omondi Bolo, Job Kihara, MonicahMucheru-Muna, Ezekiel Mugendi

4:35 – 4:45 pm On-station and on-farm testing of best-bet bean technologies, innovations and management practices in Nandi and Trans Nzoia Counties. Peter Omondi Bolo, Job Kihara, MonicahMucheru-Muna, Ezekiel Mugendi.

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4:45 – 5:00 pm Variations in plant nutrient allocation, physiological development patterns and soil structural characteristics as influenced by zero tillage systems: perspectives from short-term trials in sub-humid region in the central highlands of Kenya. Kinyua M.,Mucheru-Muna, M., Kihara, JEffect of different soil enhancements on maize grain yield and its parameters in central Highland of Kenya for improved productivity. Catherine Muriithi, Miriam Nyokabi, and Kellen Kagendo.Effect of fertilizer rates and variety on maize yield in different counties of western Kenya. C. M. Githunguri, A. O. Esilaba, M. Okoti, J. Miriti, D. Nyongesa, E. Thuranira, M. Koech, C. Mutoko, K. Ndungu, P. Ooro, P. Ketiem, H. Mwangi, V. Woyengo, M. Odendo, and G. Ashiono.Efficacy of Rizofos veggies on plant vigour and tuber yield of potato (Solanum tuberosum). Patrick Pwaipwai Evaluation of the soil fertility status and limiting nutrients for Maize Production in Kenya. J. A. Omwakwe, George N. Chemining’wa, A.O. Esilaba, EG Thuranira.

4:20 – 4:30pm Effect of Application of Blended Fertilizers on Biomass and Grain Yields of Sorghum and Pearl Millet Under Rain-fed Condition in Kitui County, Eastern Kenya. David Macharia, Daniel Mutisya1, Emerita Njiru1, Anthony Esilaba2, Angela Kathuku-Gitonga3, Dave Nyongesa3, Cyrus Githunguri3, Elias Thuranira3, Joseph Miriti3, Michael Okoti3 and Simon Nguluu4

4:30 – 5:00pm GENERAL DISCUSSIONS5.00 – 5.30pm HEALTH BREAKDAY 3: Wednesday 20 November 2019Session 6: FIELD EXCURSION WITHIN NAKURU COUNTYChair: Dr KamoniRapporteur: E. Muya, J. MiritiRoute 1: Maraigushu-EngineerRoute 2: Mai-Mahiu Fault lineDAY 4: Thursday 21 November 2019Session 7:THEME 4: ENHANCING THE STATUS OF FOOD AND NUTRITION SECURITY AND INCOMES THROUGH SOIL HEALTH AND QUALITY IMPROVEMENT AND AGRICULTURAL WATER MANAGEMENTChair: Dr. A. KiwiaRapporteur: Dr. K. Nyabundi 8:00 – 8:30am Keynote address: Lilian W. Mbuthia - IPI8.30 – 8.45am Adoption of postharvest handling technologies of passion fruits

(Passiflora edulis Sims var.). Langat, C. K., Omami, E.N. and Mutui, T.M.

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8.45 – 9.00am Properties of spent mushroom substrate and its potential uses particularly in crop and animal production systems: A review. GateriM.W., Muriuki A.W. and E. Irambu

9.00 – 9.15am Soil health constraints contributing to maize (Zea Mays L.) Yield Gap in Upper Tana watershed of Murang’a County, Kenya. Ermias Aynekulua, *, Robin Chachaa, Ruth Sitieneib, Felix Kamaub, Klauser Dominikc,Samuel Steinerc, Damaris Mboi a, Keith Shepherda

Epidemiology, host range and molecular characterization as a control tool for groundnut rosette assistor virus in western Kenya. Mabele, A. S. Mukoye, B. Ndong’a, M. F. O., Were, H. K.and Torrance, L.

9.15 – 9.30 am Growth of rainfed maize and soil microbial dynamics under different soil agronomic practices. Methuselah M. Nyamwange, Ezekiel Mugendi Njeru, Monicah Mucheru-Muna, Felix Ngetich

9.30 – 9.45 am Effects of cattle manure on growth and yield of tomato (Solanum lycopersicum.) under greenhouse condition in Uasin Gishu County.C. Gloria, P.N.M. Njeru and S.K. Kimani

9.45 – 10.00 Effect of seed treatment on Ridomil® application frequency in managing potato late blight. Kilonzi, J.M, Mafurah, J.J, and Nyongesa, M.W.

10.00 – 10.15 PANEL DISCUSSION10.15 – 10.30 HEALTH BREAKSession 8: FARMERS’ DAYOUTREACH, FERTILIZER, PARTNERSHIPS, FARMER PLATFORM AND EXHIBITIONChairperson: Dr Immaculate Maina, CEC-Agriculture, Nakuru CountyRapporteur: Edward Muya10:30 – 11:00am Keynote address: Outreach and partnership in soil-water fertilizer

interactions for improved quality of soils, environment and agricultural products: Triple Quality Enhancement James Mutonyi – AGMARK

11:00 – 1:00 pm Fertilizer/farmer discussion forum1:00 – 2:00 pm LUNCH BREAK2:00 – 4:00 pm EXHIBITION7:00 – 10:00 pm GALLA DINNER DAY 5: Friday 22 November 2019SESSION 9:THEME 2: BALANCED FERTILIZATION Keynote address: Dr. Makepeace: A review of Cadmium Levels in Fertilizers, with respect to the Kenya Context

CROP-LIVESTOCK INTEGRATION OPTIONS FOR SUSTAINABLE INTENSIFICATION AND DIVERSIFICATION OF FARMING SYSTEMSChair: Dr. Esther M. MuindiRapporteur: Peterson Njeru

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8.30 – 8.40am Properties of Spent Mushroom Substrate and its Potential usesParticularly in Crop and Animal Production Systems: A review. Gateri M. W., Muriuki A. W. and E. Irambu

8.40 – 8.50am Crop – livestock integration systems in mountain areas of Northern Kenya. Duba Golicha and Hassan Charfi

8.50 – 9.00 Livestock Keepers in Isiolo County, Embrace New Adaptive Strategies as Mitigation Measures against the Effects of Drought. Anastasia Kagunyu, Steve Nangendo and Joseph Wanjohi

9.00 -9:10am Effect of land configuration and cow dung on maize performance in minna, southern guinea Savanna zone of Nigeria. Eze, P.C., Onyekwere, I. N., Azuatalam, C. E., Adava, A. O. and Ayankeye, O. E.

9:10 -9.20am Epidemiology, host range and molecular characterization as a control tool for groundnut rosette assistor virus in Western Kenya. Mabele, A. S., Mukoye, B. Ndong’a, M. F. O., Were, H. K. and Torrance, L.

9.20 – 9.40am Tillage practices on crop productivity in semi-arid areas of Embu and Tharaka-Nithi counties Njagi I., Micheni A., Kinuthia P., Gicheru P., Nyongesa D., Esilaba A., Thuranira E., Muriithi Sand Nthiga M.

9.40 – 9.50am Effect of tillage, liming and cropping systems on maize yields during the long rains season in different agro-ecological zones in western Kenya. C. M. Githunguri, A. O. Esilaba, M. Okoti, E. Mutuma, J. Miriti, D. Nyongesa, E. Thuranira, 3M. Koech, C. Mutoko, K. Ndungu, P. Ooro, P. Ketiem, H. Mwangi, V. Woyengo, M. Odendo, and G. Ashiono

9.50 – 10.00am Tillage, residue management and cropping systems affect soil aggregation, organic carbon and microbial biomass in tropical Ferralsols of western Kenya

10:30 – 11:00 am PANEL DISCUSSION 11.00 –11.30am HEALTH BREAKSESSION 10: SOCIO-ECONOMICS AND POLICY OPTIONS IN LAND AND WATER MANAGEMENTChair: Dr NyongesaRapporteur: Dr F. Maina11:30 -10:10 am Factors affecting adoption of Integrated Soil Fertility Management

technologies in Kenya: A case study of Machakos and Bungoma counties. Rosemary Akhungu Emongor., Enid Katungi and Roselyn Uside

11:10 -11:20 am Adoption of Postharvest handling Technologies of Passion Fruits (Passiflora edulis Sims var.) by farmers in UasinGishu County. Lagat, Cyrus, K., Omami, E.N. and Mutui, T.M.

11:20 -11:30am Demographic and socioeconomic factors influencing uptake of striga control technologies in western Kenya. Godfrey Nakitare Nambafuand Richard Ndemo Onwonga

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11:30 -11:40am Opportunities of enhancing smallholders’ agricultural productivity through irrigation: The case of Uganda. Francis M. Mwaura

11:40 -11:50 am The Climate Benign Natural Green Technology for Wastewater Treatment. Lucy Wanjohi

11:50 -12:00 am Farmer awareness and adoption of Finger Millet (Eleusinecoracana) varieties in Bomet, Kenya. Jayo Manyasi Tracyline,, Paul Kimurto1,3, Joseph Mafurah, Nancy Mungaiand BennardTowet

12:00 -12:10 am Socio-economic evaluation of the effects of different sources of inorganic fertilizers on maize yield in North Rift Kenya. Wanyama J M., Mutoko, M.C.Koech M.K., Ndungu M.K.W, Kamidi M.Wanjekeche, E.Barkutwo J.

12:10 -12:20 am Unseen value of trees in indigenous agro-forestry systemArmstrong B. Atugumya and Moses Isabirye

12:20 -12:30 am Assessment of factors influencing mechanization levels of maize value chain in Trans Nzoia County, Kenya. Bett, C.,Wawire, N., Maingi, S. and Rotich, E.

12:30 -12:40 am Fencing lands to Enhanced Climate change Resilience, promoting biodiversity regeneration and Improved Livelihoods of climate change in Migori County -Justine T. Kurui, CEO and Francis Keya, Project Manager

12:40 -12:50 am Is indigenous poultry production a suitable diversification strategy in the wake of climate change in semi-arid Kenya? -Tabby Karanja–Lumumba

12:50 -1:00 am Rice Response to Different Types of Potassium Fertilizers and their Economic Benefits in Mwea-Kenya *Gikonyo, E.W., Kimani, S.K., Gichangi, A. Kibunja1, C.N., Esilaba, A.O., Mbuthia, L.W. and Kega V.

1:00 – 1:30 pm Plenary Discussion 1:30 – 2:30 pm LUNCH BREAK

SESSION 12: BUSINESS SESSIONChair: Dr EsilabaRapporteur: Dr S.K. Kimani2:30 – 4:30pm AGM4:30 – 5:00pm CLOSING CEREMONY

DisclaimerThe views expressed herein are those of the authors and not the Soil Science Society of East Africa.

Published by the Soil Science Society of East Africa (SSSEA)

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SUB THEME 1:

Enhancing Applications of Land and Water Technologies, Innovations and Management Practices (Timps) for Adaptation and Mitigation to Climate Variability and Change

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Strategies and Technologies for Watershed Management: The Case of Kibuon and Tende rivers Catchment in South West Kenya1*Teresa J. K. Mwangi, 2Nelson L. Kidula, 2Aloys R. Ondicho, 2Dymphina K. Andima, 2Maurice C. Shiluli, 2Richard K. Kanda and 2Lawrence Tong’i

1&2Kenya Agricultural and Livestock Research Organization (KALRO), P. O. Box 523-40200, Kisii *Corresponding author’s email/ Telephone No: tjkmwangi@yahoo.com (0722443974)

AbstractTo empower communities in Kibuon and Tende river catchment address land and water resources management, conservation activities were carried out between 2011 and 2014. The activities were in the areas of soil and water conservation, protecting of water sources, afforestation and diversification of livelihoods. They were financed through CBOs to increase soil cover and support eligible alternative livelihoods while improving the water quality and quantity in Kibuon and Tende rivers. Some achievements of the funded sub projects included: Construction of 80km of retention ditches. Planting of 11.5km of Napier grass strips and establishing 114 acres of improved pastures/ fodders. Purchasing 104 dairy goats to utilize improved pastures and fodder. Planting 79 acres of cover crops and preparing 50 acres of land by conservation tillage. Planting of 23,425 superior banana plantlets. Raising and planting 2,242,464 tree seedlings and also planting additional 60,600 purchased seedlings and 8,545 assorted fruit tree seedlings. Installation of 1018 hives and construction/installation of 969 energy saving devices. Protection of eight springs to serve about 8,000 households. Construction and stocking of 116 fish ponds and removal of 2,763 Eucalyptus trees. The continued adoption of integrated conservation technologies and diversification away from environmentally destructive practices would enhance the conservation of the catchment and initiate recovery of water quality and quantity in the two rivers.

Using AQUACROP to compare climate change strategies for maize production in a Kenyan humid nitisolOnyango J. W1, Miriti J. M.2 and Esilaba, A. O 3

1Kenya Agricultural and Livestock Research Organization, Kabete, P.O. Box 14733-00800 Nairobi, joabwamari@yahoo.com. 2Kenya Agricultural and Livestock Research Organization, Muguga, 3Kenya Agricultural and Livestock Research Organization, Headquarters.

AbstractMany climate models using an annual emission of 3% over two centuries suggest median temperature increases of between 3o and 4o C in Africa by the end of the 21st Century, roughly

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1.5 times the global mean response. In this study the AQUACROP model Vs. 10 (FAO, 2012) is used with maize to compare salient aspects of planting date, irrigation and fertilization as climate change adaptation strategies for a nitisol at Kabete, Kenya. A climatic scenario assuming 10% decline in rainfall coupled with 3oC temperature elevation led to at least 6 and 12% enhanced performance of biomass and grain yields respectively. A late planted crop would suffer from reduced (0.3%) canopy cover (CC), transpiration rate (7.5%) hence biomass loss of 0.2% resulting from disuse of initial water moisture availability and nitrogen flush arising at onset. The high application of 40kg/ha of N enhanced CC without necessarily affecting the biomass and eventual yields. When 20kg/ha of N was applied it did not enhance CC but enhanced transpiration and hence biomass and especially grain yields by 24.7%. There was no need to irrigate when there is adequate rain (i.e. average to above average) as this measure only delayed the cumulative harvest index which does not translates to enhanced CC nor significantly to biomass yields.

On-station and On-farm Testing of Best Bet Bean Technologies, Innovations and Management Practices in Nandi and Trans Nzoia Counties.1 *Barkutwo, J.1, Kifuko-Koech, M.N. 1, K.W.Ndungu-Magiroi1, M. Mutoko1, M. Kamidi1, J. Wanyama1, E. Wanjekeche1, V. Ouma3, A.O. Esilaba1, J.M. Miriti2, D. Nyongesa2, C. Githunguri2, E.G., Thuranira3, M.O. Okoti 3, and L. Wasilwa3

1 Kenya Agricultural and Livestock Research Organization (KALRO)- Food Crops Research Institute, Kitale, P.O. Box 450-30100 Kitale, Kenya.2 Food Crops Research Institute, KALRO –NARL, Kabete, P.O. Box 14733-00800, Kenya. 3 KALRO Headquarters, P.O. Box 57811-00200, Kenya.

*Corresponding Author: josephbarkutwo@yahoo.com

Abstract Common bean (Phaseolus vulgaris L) yields in Kenya are low because of declining soil fertility and lack of improved varieties, and associated with abiotic and biotic factors, has been the main sources of low bean production. A field experiment was conducted in Nandi and Trans Nzoia Counties during 2016 and 2017 long rainy season. The objective of the study was to demonstrate the best performing bean varieties and management practices that will increase production in the target areas. The experiment was carried out using a randomized complete block design (RCBD) with a split –plot arrangement structure and in four replications. The trials were conducted in two mother-trials on a research field at KALRO Kitale Centre and Baraton University while replicate baby-trials were carried in farmers’ field in Trans Nzoia and Nandi Counties. The treatments included seven common bean (Phaseolus vulgaris (L) varieties (Chelalang, Ciankui, Tasha, Mwitemania (GLPX92), Rose Coco (GLP2), KK8 and the local check (Wairimu (GLP 585). Results showed that significant (P<0.05) grain yield deference among bean varieties occurred under on station conditions in 2016, while in 2017 significant differences among bean varieties occurred under both on farm and on station conditions. Across the seasons and sites, Tasha and Wairimu responded more to fertilizer application on grain yield compared to the other varieties whereas, KK8 and Chelalang gave the highest yield (2.37 t ha-1) without fertilizer application. Results demonstrated that some bean varieties responded more to fertilizer application and with good agronomic management they were likely to contribute

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to food security in the region.Variations in plant nutrient allocation, physiological development patterns and soil structural characteristics as influenced by zero tillage systems: perspectives from short-term trials in sub-humid region in the central highlands of KenyaKinyua M.1, 2*, Mucheru-Muna, M.2, Kihara, J.1

1International Center for Tropical Agriculture c/o International Centre of Insect Physiology and Ecology (ICIPE), Duduville Campus Off Kasarani Road. P.O. Box 823-00621 Nairobi, Kenya, email: j.kihara@cgiar.org 2Kenyatta University, Department of Environmental Sciences. P. O. Box 43844-00100, Nairobi, Kenya, e-mail: muna.monica@ku.ac.ke

*Corresponding author: m.kinyua@cigiar.org

AbstractThe global food requirements are projected to rise above the current demand. Surface application of residues in zero tillage results to nitrogen immobilization posing nutrient use efficiency challenges while tillage and crop residue removal destroys soil structure. Little is documented on how integrated use of crop residues and inorganic N under zero tillage could affect plant nutrient allocation, physiological development and soil structural improvement relative to conventional tillage systems in Embu. The study objectives were: (i) to assess how nitrogen and phosphorus accumulation in maize grain and stover are affected by application of different rates of residue and inorganic N in conventional relative to zero tillage systems, (ii) examine how plant physiological traits are influenced by application of different levels of residue, inorganic N and tillage and (iii) assess how application of residues, inorganic N and tillage influence soil aggregate stability. An on-station trial was set in a randomized complete block design replicated three times. Six treatments were laid, comprising of a combination of different rates of maize stover residues (0, 3 and 5 tons ha-1) and N as urea (0, 80, 120 kg ha-

1), in conventional relative to zero tillage systems. Residue application in conventional tillage systems increased N (56%) and P (29%) allocation in maize grain compared to when equivalent rates of inputs were applied in zero tillage. When equal rates of inputs are applied, conventional tillage had taller plants with higher leaf area index but with similar chlorophyll content as those of zero tillage. At 0-5 cm, the large macroaggregates were significantly affected by depth and treatment × depth interaction (p≤0.01). The ability of zero tillage+5R+80N treatment to increase P allocation and produce higher macroaggregate proportions prompts its consideration as a sustainable nutrient management system.

Using Conservation Agriculture to Conserve Soil Moisture for Enhanced maize Production and Improved Soil Properties in the semi-Arid Machakos County, KenyaGitari J. N.1*,Waweru P. K.2, Kuria P.3, Mkomwa S.3 and Onyari C. N.1

1University of Embu, P.O Box 6-60100 Embu, Kenya. Email: (*Corresponding author) 2Kenya Agriculture and Livestock Research Organization (KALRO), P.O Box 27-60100, Embu, Kenya3African Conservation Tillage Network, P.O Box 10375, Nairobi. .

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*Corresponding author: gitarijosiah@gmail.comAbstractLow rainfall and infertile soils are a major constraint to maize production in the semi-Arid parts of Kenya that account for over 79 per cent of the total country’s land area. In Machakos County, farmers continue to plant maize despite these low quantities of precipitation that are pre-dorminant. Machakos County lies between latitudes 0º45´South and 1º31´South and longitudes 36º45´East and 37º45´East. The county covers an area of 6208 km² and is located at an elevation of 790-2611 m above sea level. This county is among those found in the the arid and semi-arid (ASAL) areas of Kenya. Participatory farmer experimentation with Conservation Agriculture (CA) was undertaken for six consecutive growing seasons between July 2013 and December 2016 to determine the effectiveness of CA as a method of enhancing maize yields with the limited rainfall quantities received in Machakos. The main CA practices tested include minimum tillage, ripping, live legume cover crops as well as dead residue crop mulches all implemented under varying soil fertility regimes. The research was done across 17 administrative locations of Machakos county found in different Agro-ecological zones of the fast County. The ‘Mother-Baby’ trial design was used in all the 17 trial sites whereby farmer groups were involved in all aspects of trial management and implementation. Data collected over four to six consecutive cropping seasons indicate that the use of full CA package of minimum tillage coupled with mulching of plant residues plus use of mineral fertilizer resulted in a -two to -threefold increase in maize grain yields above the farmer practice control where neither fertilizer nor CA were used. Mean maize grain yield for the four seasons in the full CA treated plot with mineral fertilization (T6) was 1.866 t ha-1 compared to 0.749 t ha-1 in the farmer practice (T1) plots where no CA was used. The general observation was that sites located in the higher elevation exceeding 1000 m above sea level were the ones where maize crop never failed and vice versa for the low altitudinal sites of Machakos county. Initial soil characterization in the experimental or demo sites indicated that soils found in Machakos are mainly Acrisols and Ferrasols with sandy textural nature. The soils appeared to be relatively high in levels of nutrient depletion. For instance, soil organic carbon ranged from 0.30-1.51 per cent. Soil chemical analysis assessment carried out in the different CA and none-CA plots showed that after six consecutive seasons or three years of experimentation, CA practices impacted positively on soil properties that were determined. Soil organic carbon increased by up to 20 per cent in plots under full CA as compared to the farmer practice or absolute control plots. The CA practices also had some positive influence on a number of soil mineral components including phosphorus, potassium and calcium across the counties.

Prediction of infiltration rates of fallow and cultivated soils in Minna, Southern Guinea Savanna Zone of NigeriaEze, P. C.1* and Musa, J. J. 2

1Department of Soil Science and Land Management, Federal University of Technology, Minna, Niger State, Nigeria.2Department of Agricultural and Bioresources Engineering, Federal University of Technology, Minna, Niger State, Nigeria.

*Corresponding Author Email: ezepc66@gmail.com; ezepemec66@yahoo.com; peter.eze@

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futminna.edu.ngAbstractA study was carried out to determine the time required to attain final infiltration rate of soils of Gidan-Kwano (a sandy loam) and Shintako (a loamy sand) sites around Minna, and reduce the tedium, time and cost associated with the measurement of soil infiltration rate, with the aid of infiltration models. A double-ring infiltrometer was used to measure the infiltration rates of the soils at the two sites subjected to two land use management practices (fallow and cultivated soils) in Minna, Southern Guinea savanna zone of Nigeria. Infiltration runs were conducted at 0, 4, 8 and 12 weeks after cultivation. Results showed that the equilibrium (final) infiltration rate of the tested soils was attained between 1 and 2 hours. Generally, the soils under fallow exhibited higher infiltration rates than cultivated ones. Curve fitting was done on Kostiakov’s, Horton’s and Philip’s infiltration models. Infiltration data generated using Kostiakov’s model were not significantly different from field measured values at 5 % level of probability. This model, therefore, showed a greater accuracy for the soils studied, than the other two models, and is thus recommended for similar soils elsewhere in the Southern Guinea savanna zone of Nigeria.

Soil Organic Carbon dynamics from Conservation Agriculture practices in the Ferralsols of Western Kenya and Eastern UgandaP.S. Oluko a,*, J.R. Okalebob, P.O. Kisinyod, J. Nortonc, W. N’getichb, J. W. Wangolie

aKibabii University, Faculty of science, Dpt. of Agriculture & Veterinary science, P.O.Box 1699-50200, Bungoma Kenya.bUniversity of Eldoret, Department of Soil Science, P.O.Box 1125-30100, Eldoret, Kenya.cUniversity of Wyoming Department of Ecosystem Science and Management, Dept 3354, College of Agriculture and Natural Resources 1000 E. University Avenue, Laramie, WY 82071dRongo University College, School of Agriculture, Natural Resources and Environmental Studies eUniversity of Eldoret, Department Seed, Crop and Horticultural Sciences, P.O.Box 1125-30100, Eldoret, Kenya.

*Corresponding author: e-mail: olukopatrick@gmail.com

AbstractRemoval of crop residues from fields for use as fodder coupled with conventional tillage and reduced nutrient replenishment may hasten SOC decline. The study evaluated impacts of conservation agriculture (CA) on change in soil organic C (SOC) and relationship between organic matter addition in a ferralsols of Western Kenya (Bungoma and Trans-Nzoia) and Eastern Uganda (Tororo and Kapchorwa). Maize (Zea mays) and beans (Phaseolus vulgaris) crops were grown during the two year period (2011–2012). Mucuna (Mucuna pruriens) was grown as a cover crop. Treatments were tillage as main plots [Minimum (MT), No-Till (NT) and conventional (CT)], sub-plots as N-application [+N and -N] and sub-sub plots as cropping systems, in a split-split arrangement in a RCBD. Cropping systems tested were Current practice (CP)-continuous maize-beans intercrop; Rotation 1(ROT1)-maize-beans intercropping with mucuna introduced at harvest of beans; and Rotation 2 (ROT2)-maize, beans and mucuna planted in strips (4-8-6 rows of maize, beans and mucuna respectvely) and rotated every

24

season. Phosphorus and nitrogen was added as DAP and CAN. Maize monocrop received 26kg P/ha +30kg starter N/ha, beans monocrop received 40kg P/ha+30kg. Additional 30kg N/ha was added as a split-split plot in a 5m by 10m area (+N) at vegetative stage. Soil chemical analysis- pH, soil organic carbon (SOC), total N - was done at each crop harvest. CA tillage plots (MT and NT) with +N had nearly 28 and 26% higher total SOC as compared with conventional tillage in the 0–5 cm soil layer. Plots under ROT 2 and ROT 1 recorded higher total SOC stocks in the 0–5 and 10-30cm soil layers than CP plots. Level of SOC was lower under all treatments in the 10–30 cm soil layer as compared to 0-10cm. N application (+N) had a significant effect (p≤0.05) on SOC stocks in all layers, recording an increased level above –N. Maize-Mucuna-Beans strip crop rotation significantly (p≤0.05) improved SOC levels and recording ∼13% higher total SOC concentration than CP. Although MT-ROT 2 and NT-ROT 2 had no significant difference (p≤0.05) in maize grain yields, CT-ROT 2 plots yielded 13% less maize grain. Thus results indicate that CA involving MT-ROT 2 +N and residue retention enhances higher soil C retention, therefore resulting into improved soil quality and sustainable crop productivity.

The Contribution of Plastic Tube Digester (PTD) Innovations in Climate Change Mitigation and Improved Rural Livelihoods: Case Study of Central Kenya 1Matiri, F.M., 2Kiruiro, E.M, 3Amboga, S.C.

1Francis .M. Matiri. Email address: Francis.Matiri@kalro.org: Tel: 0720120265. KALRO-Embu, P.O. BOX 27-60100, EMBU.2E.M Kiruiro: Email: emkiruiro@yahoo.com. KALRO-Embu, P.O. BOX 27-60100, EMBU.3S.C. Amboga: Email: Seth.Amboga@kalro.org: Tel: 0722445621. KALRO-Embu, P.O. BOX 27-60100, EMBU.

AbstractMost of the rural communities (over 80%) in the country are highly dependent on wood-fuel, charcoal and paraffin as the main sources of energy for cooking and lighting, with consequences of deforestation and water catchments degradation. Massive carbon dioxide (CO2) production, due to tree burning, is associated with climate change, a major challenge and discourse world over. Thus, it’s of necessity to seek for promising innovations that contribute to countering these negative climate change processes while improving household livelihoods. Plastic Tube Digester (PTD) Biogas technology was introduced among small-scale dairy farmers towards this effort. The main aim of this study was therefore to assess the socio-economic and environmental impacts of PTD, challenges to adoption and suggest way forward. Data was collected using formal survey, group and key informant interviews, and analysed by use of SPSS and qualitative tools. Results indicated that most households had small dairy herd sizes (an average of three animals) under zero grazing and low level of biogas awareness (20%). PTD adoption also reduced energy costs and labour requirement, and deforestation in all the households. There were improved ecosystems (63%), improved cooking environment (90%) and increased crop productivity (80%). The main challenge to improved adoption of PTD was inadequate skilled manpower to build farmers’ capacities to adopt and install the PTD technology. Hence a need to build the capacity of local community members to accelerate capacity building, installations and information sharing at the community level for improved PTD adoption.

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Assessing the contribution of climate smart agriculture practices on the resilience of maize farmers in Bungoma County, KenyaSiminyu P. 1, Oluoch-Kosura W. 1, De Groote H. 2, Mbau J. S. 3

1Department of agriculture economics, University of Nairobi. (philipsiminyu@students.uonbi.ac.ke).1Professor, Department of Agricultural Economics, University of Nairobi. (willis.kosura@gmail.com).2Agricultural Economist, Principal Scientist. International Maize and Wheat Improvement Center (CIMMYT), (h.degroote@cgiar.org).3Department of Land Resource Management & Agricultural Technology (LARMAT). University of Nairobi. (jmbau@uonbi.ac.ke).

AbstractShocks and stresses cannot be avoided; significance has to be put on enhancing the resilience of those affected. Climate smart agriculture practices in maize production mitigates against climate change, increases yields and incomes of farmers. This study assesses if climate smart agriculture practices, in particular; intercropping maize with legumes and using animal manure as organic fertilizer enhance farmer’s resilience to maize yield loss. A structured questionnaire was administered to 250 randomly selected maize farmers in Bungoma County, Kenya. This questionnaire was set up in open data kit (ODK). A probability proportionate to size sampling technique was employed to get 10 villages and maize famers were randomly selected from the 10 villages. A maize yield loss resilience index was generated using Principal Component Analysis (PCA). To analyze the maize farmer resilience on maize yield loss that was got, this study used a structural equation model (SEM). The overall model was significant with a very low log likelihood of -2267.1837, Chi square value of 5.724 and p- value of 0.455. The results of this study indicate that when farmers use Climate Smart Agriculture (CSA) practices in their maize production their resilience to maize yield loss is enhanced. The awareness and capacity of farmers in using climate smart agriculture practices in their crop production should be enhanced. When CSA practices are used, there is mitigation against climate change, farmers adapt and become sustainable to climate change, crop yields and incomes increase.

Performance of cereals and pulses under conservation agriculture technologies in coastal KenyaPole F.N1.*, Muthiani E2., Njunie M.N.3, Kiptoo R., Maingu R.A., Munyambu P., Changasi R., Muli B.M.4, Ondiko C., Chivatsi W.S., Kengo D., Mzingirwa A., Esilaba A., Nyongesa D., Thuranira E.G., Angela K., Okoti M.O., and Wasilwa L.A.

1KALRO-Matuga. P.O. Box 4-80406, Matuga. Tel: 254733737794/+254712557178. E-mail: 2 KALRO-Mariakani. P.O. Box 34 - 80108, Mariakani. Tel: +254722899289E-mail: elizabeth.muthiani@kalro.org3KALRO-Matuga. P.O. Box 4-80406, Matuga. Tel: +254722589416. E-mail: mnjunie@gmail.com4KALRO-Mtwapa. P.O. Box 16-80109, Mtwapa. Tel: +254722841390. E-mail: musimuli2@gmail.com

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*Corresponding Author: Email. finyange@gmail.comAbstractConservation Agriculture (CA) is a way of farming that conserves, improves, and ensures efficient use of natural resources. It aims at helping farmers achieve profits with sustained production levels while conserving the environment. A study to evaluate the performance of cereals (maize and sorghum) and pulses (cowpeas and green grams) under different Conservation Agriculture technologies was undertaken in coastal Kenya (Kwale and Kilifi Counties). The trials comprised of three factors namely: mulching with two levels (mulch and no mulch); Tillage practices with three levels (Zai pit, conventional tillage and zero tillage) and crops (maize, sorghum, cowpea and green grams). The 24 resulting treatments were laid out in a split-split plot design with a total of 96 plots that were replicated four times in a randomized complete block design (RCBD). Results indicated that there were no significant differences (P>0.05) between the mulch and no mulch treatments. As regards to the conservation tillage practices, Conventional tillage was significantly different (P<0.05) from Zai pits and zero tillage. However, Zai pits and zero tillage practices showed better performance in some sites. Sorghum and cowpeas gave higher yields compared to the other crops.

Effect of tillage, cropping systems and fertilizers application on Green gram (Vigna radiata L.) biomass and grain yields in semi-arid KenyaEmerita Njiru1*, David Macharia1, Daniel Mutisya1, Anthony O. Esilaba2, Dave Nyongesa3, Angela Ndanu3, Elias Thuranira3, Michael Okoti2 and Simon Nguluu4

1Kenya Agricultural and Livestock Research Organization, KARLO Katumani. P.O Box 340-90100 Machakos, Kenya.2Kenya Agricultural and Livestock Research Organization, KALRO Headquarters. P.O Box 57811-00200 Nairobi, Kenya3Kenya Agricultural and Livestock Research Organization, KARLO Kabete. P.O Box 14733-00800 Nairobi, Kenya4South Eastern Kenya University, Main Campus. P.O Box 170-90200 Kitui, Kenya.* Correspondence: emeritanji@gmail.com; Tel: + 254722893605

AbstractCrop yields in the arid and semi-arid lands (ASALs) of Kenya are low and on the decline as a result of low soil fertility and inadequate water, among other constraints. A field study was conducted in 2017-2018 to study the effect of tillage, cropping systems and application of organic and inorganic fertilizers and their combinations on green gram yields in rainfed conditions of semi-arid Kenya. The objective was to determine the effect of different fertilizer application options on green gram biomass and grain yields, and to assess the yield of green grams under tied ridge and conventional tillage systems in sole and sorghum/green gram intercropped systems. Two tillage systems (tied ridges and flat/conventional) and four fertilizer application options (no application (Nil), Full Manure rates (FM), Full fertilizes rates (FF) and Half manure + Half fertilizer rates (HMF)) were tested. A randomized complete block design (RCBD) with split-plot arrangement and four replicates was used. Green gram variety N26 was used as the test crop. Biomass and grain data was recorded on plot basis at the end of the season and samples oven dried and weighed for extrapolation of dry yields. Data was analyzed in GenStat statistical software and means separated at P≤0.05. Results indicated that fertilizer

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options significantly affected biomass and grain yields of green grams in the cropping systems. Significantly higher yields of both grain and biomass (0.52t ha-1 grain and 2.29t biomass) were obtained in sole crops with application of FF followed by HFM (0.31t ha-1 grain and 1.89t biomass) while the control treatments gave the least yields. No significant difference was found between yields from the two tillage system. It can be preliminarily concluded that FF and HFM increased yields of green grams and could be recommended for adoption with further investigations.

Residue management and tillage practices interactions on crop productivity in semi-arid areas of Embu and Tharaka-Nithi countiesMicheni A1., Njagi I.1., Esilaba A2., Kinuthia P1., Thuranira E3, Gicheru P1.,Nyongesa D3., Nthiga M1. & Muriithi S1.

1Kenya Agricultural and Livestock Research Organization (KALRO-Embu), P.O. box 27-60100, Embu2Kenya Agricultural and Livestock Research Organization (KALRO Headquarters), P.O. box 57811-00200, Nairobi3Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. box 66730-00800, Nairobi*Corresponding author: alfred.micheni@kalro.org

AbstractConservation and utilization of soil moisture in semi-arid areas is an important management option for crop production. A study was conducted in semi-arid areas of Embu and Tharaka –Nithi Counties in Eastern Kenya to determine the effects of tillage practices on cereals and legumes grain yields. For two cropping season, October 2016 and October 2017 the trials were maintained where two residue management (removed or retained) and two tillage practices (conventional and zai pits) were tested on the effect on crop productivity. The test crops were millet, sorghum and green grams. The treatments tested in a split-split plot design arranged in three replications. The highest grain yields were recorded in Tharaka-Nithi County for all three crops. No significant effects were observed from the two residue management systems on any of the crops. However, higher grain yields were observed for the crops grown in zai pits as opposed to conventional tillage system. Thus, the zai pit tillage practice improved crop yields and was therefore recommended for scaling as an effective tillage method in the semi-arid regions.

Physical and hydraulic characterization of soils for the design of the infield water use system for improved irrigation efficiency in lower NzoiaE.M. Muya1*, M. Masaku, I.V. Sijali, L. T. Chirchir and H. Rotich

1Food Crop Research Institute, National Agricultural Research Laboratories, P.O. Box 14733-

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00800, Nairobi

AbstractFor the design and operation of the water distribution system, the supply requirements of the individual fields need to be expressed in flow rate or stream size in m3/sec. The capacity and operation of the distribution system are based on the supply requirement during the peak water use month. The function of the infield water use system is to satisfy the momentary irrigation requirements of each crop and area in terms of size (Q), duration (T) and interval (I) of supply. To achieve this, soil physical and hydraulic characterization, clustering, identification of irrigable area, and selection of optimum cropping were carried out in Lower Nzoia Irrigation Development Project area. From the results of these activities, the infield water use system design parameters were derived, aimed at establishing the optimum cropping programme, peak water use period, supply requirement, duration and design factors. The results showed that 49 ha of land were unsuitable for the intended furrow irrigation. Five clusters were identified as cluster 1 (C1), cluster 2 (C2), cluster 3 (C3), cluster 4 (C4) and cluster 5 (C5) with stream size of 1.5, 0.5, 1.0, 1.4 and 4.5 litres/second respectively. About 425 ha were found to be capable of supporting the selected cropping programme. The peak water use period was found to be between February and April with maximum average daily supply requirement of 11,266 m3/day.

Analysis of soil potential for sustainable land use planning for the third crop in Bunyala Scheme E.M. Muya1*, M. Masaku, I.V. Sijali, L. T. Chirchir and H. Rotich

1Kenya Agricultural and Livestock Research Organization, Kabete Centre, P.O. Box 14733-00800, Nairobi2National Irrigation Board, P.O. Box 30372-00100, Nairobi3Kenyatta University, P.O. Box 43844-00100, Nairobi4Ministry of Agriculture, Livestock and Fisheries. P.O. Box 34188-00100, Nairobi

*Corresponding Scientist: edwardmuya2011@gmail.com

AbstractProduction system, consisting only of rice, supported by increased use of chemical fertilizers, is unsustainable. Therefore, alternative crops were sought through analysis and delineating the project area into soil clusters in terms of physical and chemical productivity index (PI) as a basis of land use planning for alternative crops. The results showed that the project areas selected for the third crop (i.e. cluster 3 and 4) had physical productivity (PI) of 67.8, being rated as marginally suitable for the envisaged crops. The highest physical productivity index was recorded in cluster 7 with value of 96.4%, followed by cluster 6 with PI value of 74.3%. Cluster 5 had the lowest physical PI of 60.1%, being rated as non-suitable. The most fertile soil was identified in cluster 7 with chemical PI of 94.1%, followed by cluster 6 with 75.8%. Cluster 3, 4 and 5 had chemical PI ranging between 50.0 and 57.8%. The differences in PI between different clusters are indicative of the potential differences in plant response to fertilizer application, thereby, invalidating the current blanket application of the agricultural inputs. Based on these potentials, appropriate land use options are provided as well sustainable

land use plan and its implementation framework.Analysis of production systems, soil-related constraints and crop yields under different rainfall regimes in the selected project sites in eastern region of Kenya1E.M. Muya, 1P.N. Macharia, 1J.M. Miriti, 1A.O. Esilaba, 1D. Nyongesa, 1I.V. Sijali, 1A.L. Chek, C. 1H. Rotich, C. Githunguri1Kenya Agricultural and Livestock Research Organization, P.O. Box 57811-00800, Nairobi*Corresponding Scientist: edwardmuya2011@gmail.com

AbstractAnalysis of production systems and crop yields in relation to soil-related constraints and rainfall is key in improving agricultural productivity. This was done through examination of the cropping systems and soil characterization in Kenya Cereal Enhancement Project Sites in Eastern Region of Kenya. The result showed that the major crops were maize, green grams, sorghum and cowpeas, grown in 33, 30, 20 and 17% of the sampled farms respectively. With rainfall range of 400 to 872 mm received in the sampled project sites, the maximum attainable yield of the major crops, were found to be much higher than the actual yields. The yield gaps were attributed to soil-related constraints due to low water uptake, hence relatively low percentage of rainwater utilized and high level of run-off. These constraints were attributed to poor soil structure and increased rate of chemical degradation.

ICT Mediated Climate Information for Adaptation among Small Holder Farmers “the last mile” in ASAL of KenyaNdegwa William, Kenya Meteorological Department, P.O. Box 30259 00100 Nairobi. Kizito Kwena, Kenya Agricultural & Livestock Research Organization (KALRO) , Agricultural Mechanization Research Institute (AMRI), P.O. Box 340-90100, Machakos Hezron Mogaka, University of Embu, P.O. Box 6-60100, Embu. Matere Stella, Kenya Agricultural & Livestock Research Organization (KALRO)

AbstractThis study is based on a baseline assessment conducted in South Eastern Kenyan region to establish the type of climate change adaptation information accessed by smallholder farmers. The better management of the risks of climate variability and change through adaptation informed by science-based climate information and prediction has been identified as the way for the future. The Sub-Saharan Africa region lags far behind in achieving this aim and there is low uptake of climate information, particularly by small holder farmers. Evidence, however, exists for increased interest in climate information for use in decision making for agriculture production among society. ICT is an important tool to overcome the challenges of access to climate information

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for small holder farmers. In SSA the challenge of vulnerable livelihoods which need climate informed decision making, on the one hand, and the fast spread of ICT access and usage on the other, make for an interesting mix that promises potentially rewarding research. There are large proportion of marginalized rural population in Kenya, who rely on subsistence farming for food and nutrition. ICT provides an important linkage for climate information to livelihood strategies. There is in ICT mediation for climate information a huge existential and academic research issues that needs intervention. This paper offers provisional findings concerning the current status and point at available opportunity for scrutiny and progressive development on ICT mediated access and use of climate information to “the last mile”.

SUB THEME 2:

Balanced Plant Fertilization and Good Agricultural Practices for Improving Soil Fertility, Crop Productivity and Profitability

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Effect of Nitrogen Sources on Nitrous Oxide emission, nitrogen use efficiency and maize yield in Western KenyaPeter Asbon Opala1*, David Masika Musuya1 and Harun Ogindo1

1School of Agriculture and Food SecurityMaseno University

Corresponding author: ptropala@yahoo.com

AbstractAlthough high rates of nitrogen fertilizer application increase crop yields, they lower nitrogen use efficiency (NUE) and hence increase emission of nitrous oxide (N2O).We assessed the effect of applying sole inorganic or organic sources of nitrogen, or their combination, on N2O emission, maize yield and NUE at Nyakach, a lowland and Soin, a highland in western Kenya. A randomized complete block design was used with six treatments; a control with no N input, urea applied alone at 30 or 100 kg N ha-1, sole manure at 30 kg N ha-1,a combined application of manure and urea, each providing 50 kg N ha-1, and NPK (17:17:17) applied at 100 kg N ha-

1. N2O emissions were quantified by gas chromatography. The cumulative seasonal emissions were low and ranged from of 0.11 (control) to 0.31 kg N2O-N ha−1 (urea100 kg N ha-1).N2O emission was higher from urea and NPK treatments than from the urea + manure treatments at the same application rate of 100 kg N ha-1. At Nyakach there were no treatment effects on maize grain yield but in Soin, the grain yield ranged from 1.4 ton ha-1 (control) to 4.0 ton ha-1 (manure + urea). Overall, sole manure (30 kg N ha-1) gave the highest (55%) NUE while urea (30 kg N ha-1). However, at the highest N rate of 100 kg N ha-1, combined application of manure and urea had higher NUE than comparable treatments of urea and NPK fertilizer.Our findings suggest that it may be possible to improve the NUE, reduce the overall contribution of N fertilizer application to N2O emissions and increase maize yield by combining the organic and inorganic N sources.

On-station and On-farm Testing of Integrated Soil Fertility Management Strategies and Conservation Tillage Practices in Western KenyaKifuko-Koech, M.N1*, K.W.Ndungu-Magiroi, M. Mutoko, M. Kamidi, J. Barkutwo, J. Wanyama, E. Wanjekeche, V.Ouma, A.O. Esilaba, J.M. Miriti, D. Nyongesa, C. Githunguri, E.G. Thuranira, M.O. Okoti and L Wasilwa

*Correspondence: Mary N. Kifuko-Koech, KALRO- Kitale. Tel: +254 722373530, E-mail: kifukom@yahoo.com

AbstractThe present study evaluated maize (Zea mays) and bean (Phaseolus vulgaris) response to conservation tillage practices (CTP) and integrated soil fertility management (ISFM) technologies in Nandi and Trans Nzoia Counties under on-station (OST) and on-farm (OFT) trials. Two CTP (conventional and ridge tillage), three cropping combinations (pure maize and bean stand, maize and bean intercrop) and four ISFM technologies (control, inorganic fertilizer, farmyard manure and organic and inorganic fertilizer applied at half rates) were tested in a split-split plot structure replicated in a complete randomized block design. Tillage practices, cropping combinations and ISFM were assigned to the main, sub-plot and sub-

32

sub plot respectively. Maize grain yield response to ISFM technologies was superior under OFT compared to OST conditions. While bean grain yield response to ISFM technologies was variable across sites, under OST and OFT, maize yield increment above control due to inorganic fertilizer application was highest and ranged from between 53 to 60% and 62 to 104% respectively. Use of ridge tillage significantly increased maize yield by 1.2 t ha-1 above conventional method under OFT in Trans Nzoia County while no significant tillage effect was observed in other sites and seasons. Results indicated that ridge tillage and ISFM options can effectively improve maize and bean production but performance is likely to vary with seasons, sites, rainfall amount and growth limiting factors.

Rice Response to Different Types of Potassium Fertilizers and their Economic Benefits in Mwea-Kenya*Gikonyo, E.W 1, Kimani, S.K.1, Gichangi, A. Kibunja1, C.N., Esilaba, A.O.1, Mbuthia, L.W.2 and Kega V.

1Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. Box 14733-00800, Nairobi, Kenya2International Potash Institute (c/o ICL Limited), P. O. Box 29183-00100 Nairobi, Kenya

*Corresponding author: estgikonyo@yahoo.com/est.gikonyo@gmail.com/Esther.Gikonyo@kalro.org and Phone contact: +254705895208

Abstract Importance of potash fertilization on most crops to enhance crop yields for food security and income generation cannot be disregarded any more. Balanced fertilization with not only Nitrogen (N) and Phosphorus (P) but also Potassium (K) can lead to sustainable crop yields. The current study aimed at evaluating rice responses to determine the best potassium fertilizer resource for optimum rice yields. The two most popular rice varieties viz. Basmati 370 and BW 196 were grown using three common potash fertilizers in Kenya market; Murriate of Potash (MOP), Sulphate of Potash (SOP) and NPK-17-17-17 (SSS) all applied at 80 kg/ha K2O. Experimental design was, split plot design with Potash fertilizer types as main plots and rice varieties as the sub-plots. Grain yields, total biomass yields and maximum tillering were measured at maturity. Results revealed significant differences in rice paddy yields for both basmati 370 and BW 196 rice varieties. Basmati 370 yields ranged from 5.37 t/ha (with SSS fertilizer at Karaba site) to 11.37 t/ha (with the same SSS fertilizer at Wamumu site) whilst BW 196 paddy yields were higher than basmati’s yields ranging from 9.17 t/ha (with SSS fertilizer at Karaba) to 15.29 t/ha (with MOP fertilizer at Thiba site). Gross margins ranged from Ksh. 40,016/acre per season (~USD 400) for MOP fertilizer on BW 196 at Karaba site to Ksh. 225,698/acre per season (~USD 2, 257) attained with SSS fertilizer in Basmati 370 at Thiba site. The SSS fertilizer gave the highest yields in thee out of four sites and consequently would be the potash fertilizer recommended for the rice growth in Mwea-Kenya.

Overcoming Soil Acidity Constraints through Liming and other Soil Amendments in Kenya. A reviewA.O. Esilaba1, N. Mangale2, A. N. Kathuku-Gitonga2*, D. M. Kamau1, A. W. Muriuki2, D. Mbakaya3 and S. Zingore4

* Corresponding author: andanus@gmail.com

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Book of Absstracts

1Kenya Agricultural and Livestock Research Organization, Headquarters P. O. Box 57811 – 00200, Nairobi, Kenya 2Kenya Agricultural and Livestock Research Organization, Kabete. P. O. Box 14733 – 00800, Nairobi, Kenya3Kenya Agricultural and Livestock Research Organization, Alupe. P. O. Box e m a i l : dsmbakaya@gmail.com4International Plant Nutrition Institute, ICIPE Compound, P. O. Box 30772 – 00100, Nairobi, Kenya

Abstract Food production in Kenya is constrained by low and declining soil health coupled with effects of the emerging climate change leading to recurrent food and nutrition insecurity. The areas with high crop yield potential in the country are greatly affected by soil acidity due to continuous cropping, loss of organic carbon, nutrient leaching and inappropriate use of fertilizers. While use of organic and inorganic sources of fertilizers, improved seed varieties and crop protection have received much research attention, liming as one way of improving soil fertility and crop production has not received similar attention. Consequently, potential yield of crops remains constrained. Soil acidity is mainly ameliorated by applying lime or other acid∼neutralizing materials, which neutralize the acidity, raises soil pH, increases the availability of plants’ nutrients and adds calcium and magnesium to the soil. It also improves the environment for beneficial soil microorganisms thus enhancing rapid breakdown of organic materials in the soil and releases nutrients for growing plants. Soil buffer capacity determines the amount of lime per unit of soil volume needed to alter soil pH. Soils with low Cation Exchange Capacity (CEC) respond rapidly to liming than soils with high CEC. But the low-CEC soils have a high capacity for rapid leaching of the added bases, thus a quicker return to original acidity unless additional liming is done. Over-liming is recommended for soils which have low CEC, such as sand which is deficient in buffering agents such as organic matter and clay. There is therefore need for appropriate attention to be given to ameliorate soil acidity in order to maintain good soil health for food and nutrition security.

Zinc based fertilizer on green grams and sorghum yields in semi-arid areas of Embu and Tharaka-Nithi countiesMicheni A.N1., Esilaba A2., Njagi I.W1., Thuranira E.G3., Kinuthia P.W1., Gicheru P.T1., Nyongesa D3. & Muriithi S.N1.

1Kenya Agricultural and Livestock Research Organization (KALRO-Embu), P.O. box 27-60100, Embu2Kenya Agricultural and Livestock Research Organization (KALRO Headquarters), P.O. box 57811-00200, Nairobi3Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. box 66730-00800, Nairobi*Corresponding author: alfred.micheni@kalro.org

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AbstractZinc (Zn) is a critical micronutrient for the growth and reproduction of cereals and pulses. A study for evaluation of different rates of zinc fertilizer on sorghum and green grams grain yields was conducted at Kenya Agricultural and Livestock Research Organization (KALRO Marimanti) in Tharaka-Nithi County and at the Agricultural Technology Development Center (ATDC) in Embu County. A completely randomized design (CRD) with three replicates was used to lay out the experiments. Zinc was applied in the form of zinc sulphate fertilizer where 5 levels of zinc treatments (0, 5, 10, 15, 20kg ha-1) were incorporated into the soil before sowing the seeds. Data collected were on grain yields. Application of zinc fertilizer at 5 and 20kg ha-1) significantly improved the growth and yield parameters of sorghum and green grams. A recommendation was therefore put forward to further test the zinc element in different soils and crop species.

Demonstrating effect of using DAP and Mavuno fertilizers on groundnuts pod and pop yield in western KenyaRachier G.O1*; I.Njaro1; F. Wayua1 and D. Chengo1

1Kenya Agricultural and Livestock Research Organization, Non-ruminant Research InstituteP.O. Box 169 Kakamega

*Corresponding author: Email: rachiergj@yahoo.com

AbstractGroundnut (Arachis hypogea L.) Forms an important part of the cropping systems in western Kenya but despite this fact, yields are generally low due to a number of factors. Empty pods at harvesting is one of the reasons for the low yields. A study was carried out in three Sub-Counties; Mumias East in Kakamega County, Ugunja and Ugenya both in Siaya County during the long rains of 2018 to demonstrate effect of using DAP and Mavuno fertilizers on groundnuts pod and pop yield in western Kenya. Thirteen individual farmers participated in the trial; eight in Mumias, three in Ugunja and two in Ugenya. Two group plots in Ugunja and Ugenya comprised of 20 and 24 members respectively.A Randomized Complete Block design (RBCD) with three replicates per treatment was used in carrying out the study, where Mavuno treated plots, DAP treated plots as well as unfertilized (control) treatment. DAP and Mavuno fertilizers were applied to two groundnut varieties CG 7 and ICGV SM 90704, respectively, as basal fertilizers at a rate of 100 kg per hectare, while the Control (traditional farmer practice) received no fertilizer treatments. Plot sizes were 10 x 10 m and a spacing of 45 x 15 cm were used. The data was analyzed using Least Significant Difference (LSD) at P<0.05. The results of the study showed that there was a significant difference in bio mass production between Mavuno and DAP treatments. The control (farmer practice) had the lowest bio mass yield. There was no significant difference on pod and biomass yield between Mavuno and DAP treatments. There was no significant difference between Mavuno and DAP treatments which may need further experimentation, bearing in mind the trial was only carried out in one season. Meanwhile recommendation for smallholder farmers are to grow groundnuts using Mavuno fertilizer for planting to maximize groundnut yields.

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Book of Absstracts

Efficacy of common basal fertilizers on maize production in Nandi and Trans Nzoia Counties Ndung’u- Magiroi1, Kifuko. M.N. 1, Mutoko, C.M. 1, Wanjekeche, E. 1, Kamidi, M. 1 Barkutwo, J. 1, Wanyama, J.M., 2J.M. Miriti, 2D. Nyongesa, 2C. Githunguri, E.G. 2Thuranira, 3M.O. Okoti, 3L. Wasilwa and 3A.O. Esilaba

1Kenya Agricultural and Livestock Research Organization (KALRO), Food Crops Research Institute, Kitale, P.O. Box 450 – 30200 Kitale;2 Kenya Agricultural and Livestock Research Organization (KALRO), Food Crops Research Institute, KALRO –NARL, Kabete, P.O. Box 14733-00800, Kenya. 3 Kenya Agricultural and Livestock Research Organization (KALRO), Headquarters, P.O. Box 57811-00200, Kenya.

Corresponding author: Email: keziahmagiroi@gmail.com

AbstractDue to fertilizer liberalization in Kenya, numerous nutrient sources have become available in the market ranging from straight, single nutrient to blended fertilizers. These nutrient sources contain a range of nutrients which target correction of specific nutrient deficiencies in the soils. However, few studies have considered a side by side comparison to assess the efficacy of these fertilizers in maize production. This study assessed the response of lime (0 and 2 t ha-1) and fertilizer (DAP, Mavuno, MEA Mazao, Minjingu, 23-23-0) to maize in Nandi and Trans Nzoia Counties. Results showed significant (p≤0.05) liming and fertilizer effects in Trans Nzoia County. Maize yields increased by 1.7 t ha-1 and 0.6 t ha-1 when lime was combined with MEA Mazao and Minjingu respectively. These blends contain CaO, a liming agent, however, the response to added lime show that these blends are not efficient in liming. Among the blended fertilizers only Mavuno had sufficient liming quality as shown by the low and other cases negative effect on the agronomic efficiency of fertilizers due to lime application. In acidic soils, application of DAP, MEA Mazao, Minjingu and 23-23-0, should be accompanied by lime to improve grain yields and enhance agronomic efficiency of these fertilizers.

Potassium Essential Nutrient Status and Management in Kenyan Soils For Increased Productivity Kathuku-Gitonga A. N. 1*, A.O. Esilaba2, N. Mangale1 L. Wasilwa2, M. Okoti2, D. Nyongesa2, C. Githunguri1, J.M. Miriti1, E. Thuranira1, G. Ashiono, Woyengo V., Ooro, P.A., H.G, Mwangi, M.N. Kifuko-Koech, K.W. Ndungu-Magiroi, Kimani S. K., Gikonyo E. W., Mbuthia L., Kamau D., Kibunja C. N., M. Njunie, B. M. Muli, E. Muthiani, D. Mutisya, D. R. Macharia and C. Nekesa

* Corresponding author:andanus@gmail.com: angela.ndanu@kalro.org

1Kenya Agricultural and Livestock Research Organization, Kabete P. O. Box 14733 – 00800, Nairobi, Kenya2Kenya Agricultural and Livestock Research Organization, Headquarters P. O. Box 57811 – 00200, Nairobi, Kenya

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AbstractNitrogen, phosphorus and potassium are regarded as the main basic nutrients necessary for plant growth and production and their functions are interrelated. Potassium is necessary for regulation of plant cells for the production of proteins and enzymes, and the production is impossible without an adequate amount of it. Potassium deficiency inhibits protein production even when nitrogen is abundant. It improves disease and pests resistance, and it increases crop yield and plays significant roles in enhancing crop quality. Studies were carried out in Kenya through laboratory soil analysis, meta-data analysis and fertilizer response studies. Soils were collected in the trial sites and analyzed using wet chemistry method. For meta-analysis, published materials were collected, collated, digitized and harmonized. Benefit cost ratios were calculated for each technology to ascertain its profitability. The results showed that potassium was deficient in smallholder farms. Nitrogen, organic carbon and some micro-nutrients were also deficient. The meta-analysis results showed that, few research studies had been conducted on potassium especially in Eastern, Coast and Rift Valley. The most economical potassium responses were under application of 60 kg K/ha, although the yields were not profitable. However, the fertilizer response studies showed increased crop yields on addition of potassium fertilizer up to 40 kg K/ha. Hence lower rates of potassium (less than or equal to 40 kg K/ha) should be recommended to offset and maintain adequate potassium levels in the soil for optimum crop production and income. Nevertheless soil analysis is key before any fertilizers are added to soils.

Value addition and use of integrated soil fertility management (ISFM) technologies toEnhance production of soybean (SB 19) in Eastern KenyaPeterson N. M. Njeru1*, Stephen. K. Kimani1, Violet O. Kirigua2 and David K. Lelgut1

1Kenya Agricultural and Livestock Research OrganizationFood crops Research Institute, Muguga2Kenya Agricultural and Livestock Research Organization, HQ

*Corresponding author: Email: Peterson.Njeru@kalro.org, njerupeterson1@gmail.com

AbstractSoybean (SB 19) is a potential oil crop and a legume that can be grown in areas where dry beans grow. Soybean varieties are rich in oil, protein, iron, most minerals and vitamins required by the body. It fixes nitrogen in the soil thereby reducing soil N mining and improving the soils for cereals grown in an intercrop system. It can be used to produce oil, milk, beverages and eaten as food. The main objective of the study was to evaluate different farmer’s categories on Soybean production in Meru, Tharaka Nithi and Makueni Counties. The experimental design was arranged in baby trial arrangement where farmers were classified into three typologies based on soil conservation and integrated soil fertility management in three Counties. The results indicated that farmers in class 1 plus external soil amendment of 40 Kg P /ha + 40 Kg N /ha + manure 5 t/ha had the highest grain yield of (2.9 t/ha), (2.7 t/ha) and (2.5 t/ha) in Meru, Tharaka Nithi and Makueni Counties respectively. The grain yields were recorded in farmers classified as class 3 whom where considered as experiment controls with mean grain yielding as low as (1.5 t/ha), (1.3 t/ha) and (1.0 t/ha) in Meru, Tharaka Nithi and Makueni Counties respectively. Therefore, integration organic and inorganic inputs on Soybean production under

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Book of Absstracts

farmers in typologies class 1 could be an alternative option contribution to food security in Eastern Kenya.

Determining effect of different integrated soil fertility management on capsicum (Capsicum anuum) under controlled environmental condition C. H. Morit1, F. L. Mkandawire1 , O .H.Moracha1 , SK Kimani2, PNM Njeru2, I Sijali2 and J. Gacheru2.

1University of Eastern Africa Baraton. P.O. Box 2500-30100, Eldoret2Kenya Agriculture and Livestock Research Organization, FCRC Muguga P.O. Box 30148, Nairobi

Corresponding author: email. cheruiyothedmond@gmail.com

AbstractA study was done on capsicum (Capsicum annum) under controlled environmental conditions to determine the effect of different soil fertility management on plant height (cm), number of fruits, and crop yield (kg). The experiment was set up at University of Eastern Africa, Baraton, Agricultural Research and Demonstration Farm. The treatments were laid out in Randomized Complete Block Design, six replicates with four randomized treatments of T1 Farmer Practice (0.5kg cow manure/hole), T2 Cow Manure (5kg/m2), T3 Combined Inorganic Fertilizer (17:17:17) 5g/hole and Cow Manure (2.5kg/m2), and T4 Inorganic Fertilizer (17:17:17) 10g/hole. Treatment under organic fertilizer showed increase on number of branches (T2-11.83, T3-10.50, T1-8.67, T4-6.83 means) and plant height (T2 66.2 T1 53.8 T3 58.0 T4 44.2 means). Yield was highest for the combined interaction of inorganic fertilizer and cow manure T3 as seen on Number of Fruits (29 fruits/treatment) and Weight of Fruits (T3-9611, T2-9083, T1-8261, T4-6539 gm./treatment). The results indicate that there is need to combine Inorganic Fertilizer and well decomposed cow manure for maximum yield of capsicum (Capsicum annum). This should be done under greenhouse where climatic conditions are controlled.

Performance of open pollinated maize varieties under low Nitrogen conditions in highland and transitional ecologies of Kenya.Ligeyo D.O 1, Saina E1, Awalla B. J1, Wanyama J. M1 and Woyengo V. W2

1 Kenya Agricultural and Livestock Research Organization –Kitale Centre- P.O. Box 450 Kitale, Kenya, 2 Kenya Agricultural and Livestock Research Organization –Kakamega Centre- P.O. Box 169 Kakamega, Corresponding Author:ligeyootieno@yahoo.co.uk

AbstractAfter water, nitrogen is the single most important input for maize production, and lack of N is the principal constraint to cereal yields. However, crop plants are only able to convert 30–40% of this applied nitrogen to useful food products such as grain. An experiment was carried out evaluate the effect of low N on open pollinated maize genotypes. Fourteen test OPVs and one check were evaluated under low N at two sites. The experiment was set up in a randomized complete block design with three replicates. The varieties were planted to two row plots of 21

38

hills spaced 0.25 m apart with an inter-row spacing of 0.75 m. Phosphorus was applied in form of Triple Super Phosphate at the rate of 36 kg P ha-1, but no topdressing was done. Analysis of variance revealed that there were significant differences (p≤0.01) between entries and entry x year for yield. Significant differences (p≤0.001) between entries for plant height, ear height and days to 50% pollen shed were observed. There were significant differences (p≤0.001) between years for yield and days to 50% pollen shed while significant site x entry and site x year interactions were observed for ear height (p≤0.05) and days to 50% pollen shed (p≤0.001). Site x entry x year interactions were only significant for days to 50% pollen shed (p≤0.001). Higher mean maize grain yields were generally achieved in year 1 (4.41 t ha-1) compared to year 2 (4.05 t ha-1). The highest mean grain yield of 4.29 t ha-1 was obtained at Kitale while at Kakamega the average yield was 4.18 t ha-1. The mean grain yield ranged from 3.74 t ha-1 in Kitale composite A to 4.77 t ha-1 in Medium altitude synthetic 1. The overall mean grain yield across sites was 4.23t ha-1. The overall mean ear height and plant height across sites was 144.8cm and 268.8cm respectively. The mean number of days to anthesis was 97.04. The mean blight, GLS and rust scores were 2.58, 2.37 and 1.64 respectively across sites indicating that rust was not a major problem. The results indicate that there is a potential to develop varieties which can extract soil available N and also utilize the N applied to the soil more efficiently. The selected OPVs have been submitted to Doubled Haploid unit for extraction of inbred lines which will be used to develop future hybrids.

Effect of Fertilizer Rates and Variety on Bean (Phaseolus vulgaris L.) Grain Yields in Different Counties of Western Kenya1C. M. Githunguri, 2A. O. Esilaba, 2M. Okoti, 1J. Miriti, 1D. Nyongesa, 1E. Thuranira, 3M. Koech, 3C. Mutoko, 3K. Ndungu, 4P. Ooro, 4P. Ketiem, 4H. Mwangi, 5V. Woyengo, 5M. Odendo, and 5G. Ashiono

1Kenya Agricultural and Livestock Research Organization (KALRO), Food Crops Research Centre Kabete, Nairobi, P.O. Box 14733– 00800; Tel: 0726959592; 020-2464435; Email: cyrusgithunguri@yahoo.com; cyrusgithunguri@gmail.com; jmmiriti2008@gmail.com; dave.nyongesa@kalro.org; elias.thuranira@kalro.org2KALRO Headquarters, P. O. Box 57811-00200, Nairobi; Email: anthony.esilaba@kalro.org; michael.okoti@kalro.org3KALRO- Kitale, P. O. Box 450-30200, Kitale. Tel: 0203509161, Cell phone: +254-717646971Email: mary.koech@kalro.org; morgan.mutoko@kalro.org; keziah.ndungu@kalro.org4KALRO – Njoro, Private Bag (20107) Njoro; Tel: +254-020-3510865; Email: patrick.ooro@kalro.org; patrick.ketiem@kalro.org; hgachuna2003@yahoo.co.uk5KALRO – Kakamega. P.O.BOX 169 – 50100, Kakamega; Tel: 020 2619792; Email: vincent.woyengo@kalro.org; martins.odendo@kalro.org; gerald.ashiono@kalro.org

AbstractBeans (Phaseolus vulgaris L.) are the most important pulses ranking second to maize in importance as food crops in Kenya. They provide cheap source of protein-and essential amino acid (lysine) for majority households. Bean production is mainly at subsistence level by smallholder farmers. The crop is grown either as pure stand or as intercrops with other crops such as maize. Different bean varieties from different sources were tested under recommended rate of fertilizer and no fertilization in Nakuru, Nandi, Trans-Nzoia, Kakamega, and Bungoma Counties. In Nakuru County Ciankui, Tasha, Chelalang, GLP-x-92, and GLP-2

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varieties produced significantly higher yields than the local checks (Saitoti) and KK8. In Nandi County, Wairimu, gave significantly higher grain yields than varieties, Tasha, Chelalang, KK8, Ciankui, GLP-2, and GLP-x92. The bean varieties exhibited similar yields in Nakuru and Nandi Counties when assessed under optimum and no fertilizer application. This suggested that the varieties are quite stable in terms of fertilizer needs. In Trans-Nzoia County, with or without fertilizer application, variety Wairimu gave significantly higher grain yields than the other six varieties, Tasha, Chelalang, KK8, Ciankui, GLP-2, and GLP-x92. In Kakamega County, variety Chelalang produced significantly higher grain yields than varieties, GLP-2 (Rosecoco), GLP-x92 (Mwitemania), and Canadian wonder. All seven varieties, Tasha, Chelalang, KK8, GLP-2, GLP-x92, Wairimu, and Canadian wonder, produced statistically similar yields in Bungoma. Application of fertilizer in Trans-Nzoia , Kakamega and Bungoma Counties resulted in significantly higher bean grain yields than those grown without fertilizer meaning fertilizer application by farmers to their bean crop should be encouraged in these three Counties.

Effect of Fertilizer Rates and Variety on Maize Yield in Different Counties of Western Kenya1C. M. Githunguri, 2A. O. Esilaba, 2M. Okoti, 1J. Miriti, 1D. Nyongesa, 1E. Thuranira, 3M. Koech, 3C. Mutoko, 3K. Ndungu, 4P. Ooro, 4P. Ketiem, 4H. Mwangi, 5V. Woyengo, 5M. Odendo, and 5G. Ashiono

1Kenya Agricultural and Livestock Research Organization (KALRO), Food Crops Research Centre Kabete, Nairobi, P.O. Box 14733– 00800; Tel: 0726959592; 020-2464435; Email: cyrusgithunguri@yahoo.com; cyrusgithunguri@gmail.com; jmmiriti2008@gmail.com; dave.nyongesa@kalro.org; elias.thuranira@kalro.org2KALRO Headquarters, P. O. Box 57811-00200, Nairobi; Email: anthony.esilaba@kalro.org; michael.okoti@kalro.org3KALRO- Kitale, P. O. Box 450-30200, Kitale. Tel: 0203509161, Cell phone: +254-717646971Email: mary.koech@kalro.org; morgan.mutoko@kalro.org; keziah.ndungu@kalro.org4KALRO – Njoro, Private Bag (20107) Njoro; Tel: +254-020-3510865; Email: patrick.ooro@kalro.org; patrick.ketiem@kalro.org; hgachuna2003@yahoo.co.uk5KALRO – Kakamega. P.O.BOX 169 – 50100, Kakamega; Tel: 020 2619792; Email: vincent.woyengo@kalro.org; martins.odendo@kalro.org; gerald.ashiono@kalro.org

AbstractIn Kenya the highest maize production is found in the high potential central highland zones while the lowest potential for increasing is in the lowland regions. Kenya has lost its competitiveness in maize production to the neighbouring regions due to the high cost of production. One of the most important avenues for reducing production cost is to increase yield per unit area by use of quality seed and appropriate fertilizer. The performance of maize varieties grown in Western Kenya under the recommended fertilizer application rates and management practices were evaluated in Nakuru, Trans Nzoia, Nandi, Kakamega and Bungoma counties during the 2017 long rains season. All varieties gave lower yields than their genetic potential across all Counties. In Nakuru County, the yield of the varieties tested were not significantly different across all the sites. However, those grown with fertilizer produced significantly higher yield

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than those planted without. In Nandi County variety H6213, produced significantly higher yield than the other varieties whether planted with or without fertilizers and was closely followed by varieties H628, H6210, PAN691, H600-11D, and KH600-23A with Pioneer variety producing the lowest yield. In Trans Nzoia County varieties H6213, H629, PAN691, and H6210 were the highest yielding, while H600-11D, H628, PIONEER were the lowest yielding. Varieties H6218, H614D, and KH600-23A had moderate yields. Maize grown with fertilizer produced significantly higher yield than those planted without. The ten varieties tested in Kakamega were not significantly different from each other. However, those grown without fertilizer produced slightly lower yields than those planted with fertilizers. Similar trends were obtained for the ten maize varieties tested in Bungoma County even though the yields obtained were much lower than those obtained in Kakamega County under similar environments and field management. Generally, selection and recommendation of varieties should not only be based on mean yield across different production environments per se but also on genotypic stability since stable varieties are climate smart. Varieties with above average yield that maintain consistent high rank across different environments should be selected and recommended.

Evaluation of different fertilizer application techniques on the growth and leaf yield of nightshade under greenhouse condition in Baringo County.G. Kigen, P.N.M. Njeru, S. S. Kimani and I. Sijali.

Corresponding Author: Geoffrey Kigen

Kenya Agriculture and Livestock Research Organization, ARI- Perkerra P.O. Box 32- 400, Baringo Email; Kigenkibet23@gmail.com

AbstractAfrican Indigenous Vegetables form an integral part of the Kenyan diets, among the Most commonly consumed being the African nightshade. These vegetables contain important phenolics that have medicinal values and good health attributes. They are also an insurance against food insecurity and malnutrition by providing readily available vegetables of high nutritive value which require minimum production input. Nutrients contained in African nightshade including proteins, amino acids, vitamins, and fiber. The most parts being consumed in this vegetable are leaves sometimes tender top part of the stem. Therefore, the goal of the study was to evaluate different fertilizer application techniques on the growth and number of leaves of African night shade under greenhouse condition in Baringo County. Four treatments were used which were; bare soil (farmers practice), organic manure, inorganic fertilizer, and combined organic and inorganic fertilizer. The experiment was done in Complete Randomized block Design (CRD) with three replicates.. Neither height nor number of leaves had significance difference. Though mean of heights of plants planted with manure alone were highest followed by combined fertilizer and manure then fertilizer a lone and finally control had the lowest mean of number of leaves. Combined fertilizer and manure had the highest mean of number of leaves, followed by manure a lone, the fertilizer and lastly control treatments. We therefore recommend the use of manure alone when planting African night shade since use of manure combined with fertilizer will increase the cost of production and majority of people prefers vegetables grown by use organic fertilizer.

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Yield Response of Finger Millet to Poultry Manure application in Western KenyaMakete, N. N1*, Oduori, C.A., Opole, R.A., Mulindo, C.J., and Nungo, R.A.

1*Kenya Agricultural and Livestock Research OrganizationP.O. Box 169-50100, Kakamega Kenya.

*Corresponding author: neks2030@yahoo.com

AbstractDeclining soil fertility is affecting finger millet production in Western Kenya and inorganic fertilizer use is proving expensive for most small holder farmers. With over 90% of small holder farmers keeping poultry, its manure appears to be a potential alternative source of fertilizer for finger millet production. An experiment was conducted to evaluate the yield response of finger millet (Eleusine coracana) to different rates of poultry manure (0, 5, 10, 15, 20, 25 and 30t/ha). The study was conducted on-station at KALRO-Kakamega during the 2016 long rains (March – August) and 2016 short rains season (September – December). Experimental layout was Randomized Complete Block Design with three replications. Well decomposed poultry manure was incorporated into plots before planting. Results from this study indicated a significant yield increase from 1148kg/ha (control) to 1925.9kg/ha (5t/ha rate) which was also significantly different from the 10t/ha rate (2463kg/ha) during the long rains season. No significant yield increase was observed beyond 10t/ha rate. No significant yield difference was recorded with increasing rates of poultry manure during the short rains season. This clearly indicated that finger millet yield may have been affected by other factors besides poultry manure rates. Significantly higher finger millet mean yields were recorded during the long rains season (2431.74kg/ha) when compared to the short rains season (936.51kg/ha). The positive yield response of finger millet variety U-15 to increased rates of poultry manure during the long rains season indicates that smallholder farmers can consider using poultry manure (5-10t/ha) as an alternative fertilizer for finger millet production.

Effect of different potassium fertilizer rates and liming on recommended maize yield grown in western KenyaCyrus M Githunguri1*, Joseph M Miriti1, Elias G Thuranira1, Mary N Koech2, Keziah W Ndungu2, Vincent W Woyengo3, Gerald Ashiono3

1Kenya Agricultural and Livestock Research Organization (KALRO), Food Crops Research Centre Kabete, Nairobi, P.O. Box 14733– 00800; 2KALRO- Kitale, P. O. Box 450-30200, Kitale; 3KALRO – Kakamega. P.O.BOX 169 – 50100, Kakamega

*Correspondence: cyrusgithunguri@yahoo.com; cyrusgithunguri@gmail.com

AbstractDespite the importance of maize, yields per acre have continued to decline in Kenya which is majorly attributed to low soil fertility. Potassium (K) is the third major primary essential nutrient after nitrogen and phosphorus which is required by plants in large quantities. Potassium regulates the uptake of nitrates from the soil, has a balancing effect on phosphorus uptake and

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strengthens stalks of plants which enhances the plants resistance to fungal and bacterial attacks and lodging. It also influences very many physiological processes in plants such as transpiration, synthesis of carbohydrates, proteins and translocation of the synthesized food. Potassium deficiency in Kenya may manifest in some soils depending on the management practices. Several fertilizer companies in Kenya include K in their product. Since K is a very expensive nutrient, these trials sought to assess the K response in maize production in selected western Counties. The broad objective of the study was to determine the crop response to potassium in western Kenya. The specific objective of the study was to demonstrate the effect of potassium and liming on the yield of maize in selected western Kenya sites. The trials were established in KALRO Njoro, Nakuru County; Baraton University; Nandi County; KALRO Kitale; Trans Nzoia County; KALRO Kakamega; Kakamega County; and Bungoma Agricultural Training Centre in Bungoma County during the 2017 long rains season. Lime was applied at two levels (with and without lime) and K at 0, 40, 80,120, 160 and 200 kg K20 ha-1. All the plots received a blanket application of nitrogen (N) and phosphorus (P) at the recommended rates of 60 kg N and 60 kg P2O5 ha-1. The treatments were arranged in a split- plot in a randomized complete block design replicated four times. Lime was allocated to the main plot and the various K rates to the sub-plots. The trial was established in plot sizes of 6 m x 4 m with a harvested area of 9 m2. Potash was applied at different rates as K2O in form of Muriate of Potash as follows: i) absolute control (nil); ii) recommended N and P minus K (NP); iii) NP + 40kg K2O ha-1; NP + 80 kg K2O ha-1; iv) NP + 120 kg K2O ha-1; v) NP + 160 kg K2O ha-1; and vi) NP + 200 kg K2O ha-

1. Prior to land preparation, soil sampling was conducted for analysis of selected physical and chemical properties. Basal N and P was applied as Mavuno fertilizer (10-26-10) by banding at 60 kg N and 60 kg P2O5 ha-1. Maize variety H6218 was planted at 0.75 m between rows × 0.25 m within the row. Recommended agronomic practices were followed. At six weeks after crop emergence, calcium ammonium nitrate, was used for topdressing. At harvest the grain was oven-dried to attain a moisture content of 12.5%. Data was subjected to analysis of variance (ANOVA) to determine the effect of treatments using SAS. Means were separated using least significant difference at 5% level of significance. Plots without liming that were supplied with 200 kg K ha-1 produced significantly higher (p≤ 0.05) maize yield at KALRO Njoro in Nakuru County than those supplied with Nil, NP_0K, NP_80K, and NP_160K kg ha-1. However, plots without liming that were supplied with NP_40K and NP_120K kg ha-1 did not produce significantly (p≤ 0.05) different yield than those supplied with 200 kg K ha-1. On the other hand, where lime was supplied there were no significant differences in maize yield obtained with different K rates. In Nandi County, though not significantly different from the other K rates, maize supplied with NP_160 kg K20 ha-1and with or without lime produced significantly (p≤ 0.05) higher yields than those without fertilizer. In Trans Nzoia, Kakamega and Bungoma Counties sites, maize response to K was not significant. There could be some interactive effects between K and lime that could be inhibiting uptake of K by maize plants in the KALRO Njoro site. Potassium was adequate in the Trans Nzoia, Kakamega and Bungoma Counties trial farms and as such application of K based fertilizers is not necessary in these sites, considering the high cost of K. The application of K and liming has the potential to produce positive responses on maize grain yields. The lack of differences between lime and no lime application may be due to the method of lime application, which may have negatively affected plant germination. As such, the method of lime application is likely to be a key factor in maximising the expected interactions between liming, K and NP. Finally, potassium application above NP_40 kg K+/ha in Nakuru and Nandi Counties County may not be necessary.

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Participatory On-farm Trials Providing Soil Fertility Information on Raising Maize Yield in Semi-Arid Eastern Kenya1C. M. Githunguri, 2A. O. Esilaba, 3S. Zingore, and 1C. Kibunja

1Kenya Agricultural and Livestock Research Organization (KALRO), Food Crops Research Centre Kabete, Nairobi, P.O. Box 14733– 00800, KenyaEmail: cyrusgithunguri@yahoo.com; cyrusgithunguri@gmail.com; catherine.kibunja@kalro.org2Kenya Agricultural and Livestock Research Organization, P. O. Box 57811-00200, Nairobi; Email: anthony.esilaba@kalro.org3International Plant Nutrition Institute, Nairobi; Email: szingore@ipni.net

AbstractSmallholder farmers in the southern rangelands of semi-arid eastern Kenya keep on growing maize despite frequent crop failures and receiving extension communications that clearly recommend growing of other highly drought tolerant crops. Thus to mitigate frequent serious food and nutrition shortages, there is need for appropriate agronomic recommendations. Onfarm soil nutrient agro-ecological intensification and omission trials were established at Makindu in the Southern Rangelands of eastern Kenya. A 10 km radius transect in Makindu / Kiboko area in Makueni County was selected and 30 onfarm trials established to evaluate and promote site-specific nutrient management recommendations. Maize responded positively to applications of NPK + Mavuno, NPK + Lime (1000kg/Ha), and NPK + Manure (10 T/Ha). Micronutrients (Mavuno), lime, and manure had positive effects on performance of maize. As such, complimentary addition of manure, micronutrients (Mavuno), and lime should be encouraged in the semi-arid areas. There is need to demonstrate and communicate to farmers the need to adopt an integrated natural resource management approach in crop production in the semi-arid areas. In addition, there is also need to create awareness among farmers on appropriate soil and water management options through appropriate training.

Effect of Integrated Soil Water and Fertility Management in Maize - Bean Cropping System in Western Kenya1 Ashiono, G.B., 1Woyengo, V., 2 Esilaba, A.O. and 2 Wasilwa, L.

1Kenya Agricultural and Livestock Research Organisation P.O Box 169-50100 Kakamega. 2Kenya Agricultural and Livestock Research Organisation P.O Box 169-50100 Kakamega.Corresponding author: Email:gashiono@gmail.com

AbstractDegraded lands, inadequate soil moisture and low soil fertility have been identified as some of the principal factors limiting crop production in Kenya. A trial was conducted for two seasons to determine the effect of tillage, nutrient management and cropping systems on maize and bean yields in Kakamega and Bungoma Counties of western Kenya. Maize variety 6218 and bean variety KK8 were used in the experiment as pure stands and in combination. Treatments factors were tillage (flat cultivation and ridges), fertilizer management (No fertilizer, inorganic fertilizer, Manure and their combinations) and cropping systems (sole Maize, sole beans and Maize intercropped with beans). The treatments were laid out in a split-split plot design with

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the tillage systems allocated to the main plot, cropping systems to the sub-plot and fertilizer sources to the sub-sub plots in a randomised complete block design (RCBD). Treatment effects were determined using grain yield.Tillage systems did not confer a significant (P<0.05) advantage to crop production in Kakamega County. Mean grain yields of maize were similar under conventional tillage (6.999 kg/ha-1) and ridges (7.091 kg/ha-1) while mean grain yields of beans were equally similar under conventional tillage (389kg/ha-1) and ridges (460kg/ha-1). However in both cases higher grain yields were obtained under soil water conservation system (ridges). In Bungoma tillage systems were not significantly (P<0.05) different but higher grain yields were obtained under ridge tillage (1532 kg/ha-1) compared to Conventional tillage (1445 kg/ha-1).Cropping systems were not statistically different (P<0.05) in Kakamega although higher mean maize grain yields (7192kg/ha-1) was produced in mono cropping compared to intercropping (6.897 kg/ha-1). In Bungoma cropping systems were also not significantly different however higher maize grain yields were obtained in intercropping (1500 kg/ha-) compared to mono cropping (1477 kg/ha-1). Fertilizer application in Kakamega did not differ significantly among the different levels although higher mean grain yields (7179kg/ha-1) were obtained when Half Manure and Half Fertilizer were applied. Fertilizer application in Bungoma was significantly different (P>0.05) with higher yields (1891kg-ha) obtained where Full Fertilizer (FF) was applied followed by Half Manure and Half Fertilizer (HMF) which produced (1649kg/ha-1).The study has shown that any of the tillage systems are suitable for Kakamega while in Bungoma ridge farming is more beneficial while and nutrient addition to the soil can enhance crop production with the application of half fertilizer and half manure (HMF).

Effects of Tunza organic bio -fertilizer on maize crop yields, soil nutrients and microbial dynamicsIrambu. E. M1*, Kibunja, C.N., Thuranira, E.G and Mary.W. Gateri.

1*Kenya Agricultural Research and livestock research organization –KabeteP.O Box 14733- 00800 Nairobi

Corresponding Author: eirambu2@yahoo.com

AbstractIn this study, the efficacy of TUNZA a bio-fertilizer imported from USA and marketed by African Bio products Ltd in Kenya was evaluated under greenhouse conditions in three soil types from Matuu, Mwea and Kabete. The soils were selected from 3 diverse agroecological zones of the country The objective of the study was to assess the effectiveness of the bio-fertilizer in enhancing crop yields without endangering the indigenous soil biodiversity. The three soils had varying inherent soil fertility and represent different soil types in the country. Kabete soil was representative of moderately fertile humic Nitisols; Mwea soil was representative of [Vertisols] while Matuu soil was representative of [Acrisols]. The experiment was laid out in a randomly complete block design (RCBD) using seven treatments and replicated three times. Maize was used as the test crop. Application of TUNZA had no significant effect on pH, phosphorus, magnesium, calcium and potassium levels of the tested soils. However it was found to increase organic carbon and nitrogen in Mwea soil. It also significantly increased manganese in the Kabete soil and sodium in all the soils. Overall it significantly enhanced the uptake of all the

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major and minor nutrients. TUNZA enhanced growth in form of increased bio-volume, height, root volume, root mass, girth and chlorophyll. It also increased the dry matter yields. The order of performance was as follows: NPK = TUNZA + NPK =TUNZA (L) = TUNZA (H) =TUNZA (L} +NPK + FYM > Cont =FYM. Generally most parameters showed significant soil x treatment interaction effects implying that treatment effects differed from one soil to the other.TUNZA is not harmful to the soil microbes. Indeed its application significantly increased the population of bacteria in all the soils. It increased the microbial activity in the Kabete soil. Thus it can be concluded that use of TUNZA as a bio-fertilizer is beneficial to crop production as well as soil fertility improvement. It can be applied alone or in combination with either FYM or inorganic fertilizers. The product needs to be tested under field conditions in Kabete, Mwea and Matuu so as to evaluate its agronomic effectiveness in those soils and application rates.

The Effective Method in Making Goat Manure-Based Vermicompost for Organic Garlic Production in Manyatta sub-county, KenyaGichaba, V.M1*, Ndukhu, H.O1, Muraya, M1, Odilla, G.A2

1Department of Plant Sciences, Chuka University, P.O. Box 109-60400, Chuka Kenya2Department of Agricultural Education, Agricultural Economics and Agribusiness Management, Chuka University, P.O. Box 109-60400, Chuka Kenya

*Corresponding Author: Email: vincent.gichaba@gmail.com

AbstractMany recent studies have demonstrated the effectiveness of vermicompost in providing essential soil nutrients for plant growth and development and results have shown that application of vermicompost brings about improvement in soil chemical properties. The continued use of chemical fertilizers in garlic production causes health and environmental hazards such as ground and surface water pollution by nitrate leaching. Besides, in recent times more consumers prefer organically produced products. Goat manure-based vermicompost was prepared at KALRO Embu station, Embu County between July – November 2018. The vermicompost obtained was dried, screened and filled into bags and was used for growing garlic. A sample of goat manure-based vermicompost was analysed for chemical properties and the results showed that it had high total N (1.79%), high available P (52 ppm), high exchangeable K (1.75 Cmol Kg-1) and it was moderately alkaline (pH 7.73). Hence, goat manure-based vermicompost will be recommended in the organic production of garlic in Eastern Kenya.

Effect of fertilizer on yield performance and stability on popular maize varieties in Mid-late agro-zone of western KenyaWoyengo V.W1, Ashiono G1, Odendo M.1, Onyango E.1, Esilaba A. O.2, Nyongesa D. W.3, Githunguri C.M3 , Thuranira E. G.3, Miriti J. M.3., Okoti M. O.2,and Lusike, W.2

1KALRO–Kakamega. P.O.BOX 169 – 50100, Kakamega; Tel: +254 729981023; Tel: 020 2619792; Email:

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vwoyengo@gmail.com; vincent.woyengo@kalro.org; martins.odendo@kalro.org; gerald.ashiono@kalro.orgeunice.onyango@kalro.org;2KALRO Headquarters, P. O. Box 57811-00200, Nairobi; Email: anthony.esilaba@kalro.org; michael.okoti@kalro.org3KALRO, Food Crops Research Centre Kabete, Nairobi, P.O. Box 14733– 00800; Tel: 0726959592;020-2464435; Email: cyrusgithunguri@yahoo.com; jmmiriti2008@gmail.com; dave.nyongesa@kalro.org; elias.thuranira@kalro.org

AbstractMaize varieties development and release in Kenyan is under optimal fertilizer condition targeting different macro agro-ecological zones (AEZ). There is need to determine the performance of the commercial under sub-optimal fertilizer condition, a common phenomenon on farmers’ fields. Ten popular commercial maize varieties in mid-late agro ecological zone were evaluated using mother-baby trials under optimum and no fertilizer. Variety, fertilizer, site, year and their interactions MS were significant (P<0.05) indicating significant genotypic differences between the varieties, effect of fertilizer use, test location, year and genotype x environment interaction on grain yield. Differences between variety, effect of fertilizer and their interaction necessitates selection of superior varieties and fertilization regime to be based on both mean performance but also stability. Only H624 produced above average mean grain yield of 6.18t/ha and 3.99t/ha when grown with and without fertilizer, respectively. H614D and H624 with bi value of 0.92 and 0.91 (closest to one) and with the lowest absolute (bi-1) values of 0.08 and 0.09, respectively are the most stable genotypes under varying soil fertility. H624 is therefore both a high yielding and stable variety across varying soil fertility and should be recommended to farmers mainly resource poor farmers. All varieties highly responded to fertilizer application (mean yield increase of between 42% and 99%) irrespective of site and year implying in order to realize good yields, farmers must use fertilizer.

Effects of Cattle Manure on Growth and Yield of Tomato (Solanum lycopersicum.) under Greenhouse Condition in Uasin Gishu CountyC., Gloria1*, P.N. M. Njeru and S.K. Kimani

Mateeny Soy Farmers Cooperative society limited, P.O Box 269-30105 Soy

*Corresponding Author: tetichgloria@gmail.com

Abstract The tomato is the edible, often red, berry of the plant solanum lycopersicum, commonly known as a tomato plant. The species originated from South America. Though we technically eat the fruit of the tomato plant, the tomato is typically treated as a vegetable in eating and cooking and thus categorized as such .Tomatoes are an important commercial crop for horticulture farmers in Kenya. The market is strong and the crop is relatively easy to grow. It is a favorite for greenhouse farmers. Globally the demand for food is increasing due to increase in

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population. Degrading soils necessitates novel approaches to soil fertility management. The aim of this research was to investigate the effects of cattle manure and inorganic fertilizer in tomato production under greenhouse conditions in Uasin-gishu County, Kenya. The research treatments were organic manure, inorganic fertilizer, combined inorganic and organic fertilizers and a farmers practice. The treatments were arranged at a completely Randomized block design with six replications making a total of twenty four plots. Tomato growth characteristics and yield were measured and the data subjected to analysis of variance (ANOVA) Combination of organic and inorganic fertilizer recorded the highest number of fruits hence highest yield. On the other hand Farmers practice gave the lowest number of fruits thus lowest yield. The study concluded that combination of organic and inorganic supplied the require plant nutrients, improves soil structure and water holding capacity. It is therefore recommend to greenhouse farmers to use combination of organic and inorganic fertilizer for maximum tomato production.

Efficacy of Rizofos veggies on plant vigour and tuber yield of potato (Solanum tuberosum)Pwaipwai, P.

AbstractEfficacy trials were conducted to evaluate the efficacy of Rizofos veggies on performance and yield of potato. Rizofos Veggies is a bio-fertilizer containing Pseudomonasfluorescens bacteria that increases soil phosphorous availability by mineralizing the organic fraction and solubilizing the inorganic nutrients present in the rhizosphere which could be complexed in the rhizosphere. The trials were carried out in February 2016 and September 2017 in three potato growing counties (Kiambu-Tigoni, Nyandarua- Njabini and Nakuru- Molo). The experimental plots measured 3.75m by 6m,had five rows planted at a spacing of 75cm by 30 cm, to give a population of 100 plants/plot. The treatments were 6 namely T1-Control, T2-DAP (200kg/acre) alone, T3-DAP (100kg/acre) alone, T4-Rizofos alone, T5-Rizofos+DAP (200kg/acre) and T6-Rizofos+DAP (100kg/ha) arranged in Randomized Complete Block Design (RCBD) with four replications. Well sprouted seed potato tubers of variety Shangi, a popular highly marketable commercial variety released in 2015 obtained from KALRO Seed unit was used. Data on yield was collected at harvesting and analyzedfor variances (ANOVA) using the GenStat statistical Package (Gen, 2012). Treatment means were separated using Fischer’s LSD at 5%.Application of Rizofos significantly (P≤0.05) affected the number of tubers produced by each plant at each trial sites in both seasons (Table 1). The treatment with the highest number of tubers was DAP 100 kg/ha with 8.25, an increase of 19.5% compared to control. In regards to tuber yield, significant effect (P≤0.05) of Rizofos was recorded on tuber yields (Table 2). Indeed, even when applied alone, Rizofos produced a significant increase in tuber yield 11.56kg compared to 9.10kg (this represented a 27% increase). Application of Rhizofos in combination with full rate of DAP (200kg/acre) produced the highest yield of 13.35kg (47% above the NIL Control). This yield is not statistically different from the yield achieved after application of Rizofos and half rate of DAP fertilizer (100kg/acre) that had had an equivalent of 32% increase in tuber yield above the NIL control.When assessed as an individual applicationplanting, Rizofos alone yielded highest in Njabini and lowest in Molo, implying that the organisms unlocked phosphates in the soil thus releasing nutrients and phytohormones in the soil for plant utilization. As the results of the efficacy trial show a consistent positive effect of Rizofos with no adverse effect on potato acrossthetestingsites, thus useofRizofos is recommended for use in Kenya.

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Evaluating the effects of a formulated slow release nano-composite NPK fertilizer on growth and yield of maize, kale and capsicum*Kiplangat Rop1, George N. Karuku2, Damaris Mbui1, Njagi Njomo1, Immaculate Michira1

1Department of Chemistry, University of Nairobi. P.O. Box 30197-00100, Nairobi, Kenya. Email: dmbui@uonbi.ac.ke, imichira@uonbi.ac.ke, njaginjomo@uonbi.ac.kebDepartment of Land Resource Management and Agricultural Technology, University of Nairobi. P.O. Box 29053-00625, Kangemi, Nairobi, Kenya. Email: gmoe54321@gmail.com

*corresponding author, Email: kiplangatrop@uonbi.ac.ke or kiplangatrop@gmail.com

Abstract Effect of formulated slow release NPK fertilizer [cellulose-graft-poly(acrylamide)/nano-hydroxyapatite/soluble fertilizer] composite (SRF) on the performance and yield of maize, kale and capsicum was evaluated in a greenhouse experiment. No significant difference in growth parameters was observed between SRF and commercial fertilizer (CF) treatments. SRF recorded higher dry matter and yields relative to CF with similar application rates, though statistically insignificant. P deficiency was observed in maize at lowest SRF applicationrateof45-57-17. N deficiency in CF was observed at the 8thweek, but not in SRF with similar application rates during the same period. Kale showed both N and P deficiencies in the 7thweek, while capsicum alone showed N deficiency in the 14th week in SRF at low application rates. NPK content in both maize and kale tissues, was significant between the amendments and control. Capsicum tissues had significantly (p≤0.05) higher N content both in SRF and CF higher application rates of 125-159-45 & 100-100-100, respectively, compared to control. At final harvest, soil samples planted with maize and amended with the highest SRF rate showed significantly (p≤0.05) higher P content, compared to lower rates and the control. The agronomic optimal rate of SRF determined by quadratic function were found to be higher than that of CF. SRF was found to enhance growth and yields of crops just like CF and could potentially have greater benefits such as improving soil health and resilience.

Formulation of slow release nano-composite NPK fertilizer using biodegradable polymer hydrogel and evaluating the release of nutrients*Kiplangat Ropa, George N. Karukub, Damaris Mbuia, Immaculate Michiraa, Njagi Njomoa

aDepartment of Chemistry, University of Nairobi. P.O. Box 30197-00100, Nairobi, Kenya. Email: dmbui@uonbi.ac.ke, imichira@uonbi.ac.ke, njaginjomo@uonbi.ac.kebDepartment of Land Resource Management and Agricultural Technology, University of Nairobi. P.O. Box 29053-00625, Kangemi, Nairobi, Kenya. Email: gmoe54321@gmail.com

*corresponding author: kiplangatrop@uonbi.ac.ke or kiplangatrop@gmail.com

AbstractSlow release fertilizer (SRF) composite was formulated by incorporating nano-hydroxyapatite (nano-HA) and water soluble fertilizers (urea, (NH4)2HPO4 and K2SO4) into cellulose-graft-poly(acrylamide) polymer hydrogel. Fourier Transform Infra-red spectra revealed existence of chemical interaction between the monomer, cellulose, urea and nano-HA. The release of nutrients

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was assessed using laboratory incubation experiment. Significantly higher content of mineral nitrogen (MN) was observed in the first 4 wks (wks) in conventional fertilizer (CF) compared to SRF treatments and the control. MN content in SRF treatments increased considerably between the 8th and 12th wk, and declined in the 16th wk. The values of potentially mineralizable N estimated using first order kinetics model related well to the observed cumulative MN at 16th wk. No significant difference was observed between CF and SRF treatments for available P content in the 2nd wk. Significantly higher P content was observed in CF compared to SRF treatment in the 4th wk, whereas in the 8th wk, some SRFs released significantly higher content than CF. Available P peaked in the 8th wk in all the treatments and remained constant at 12th and 16th wk. Availability of P in SRFs increased with increased content of soluble P and decreased content of nano-HA. Exchangeable K showed less variation during the incubation period, suggesting short release time. The data revealed reduced chances of leaching losses and toxic effect to the plant roots, as well as synchronized nutrient release and requirement by crops.

Prospects of using Integrated Soil Fertility Management practices for improved Soil Productivity and Food Security in Machakos CountyS. W. Wamalwa1, Danga, B1. and Kwena, K2

1Department of agricultural Resources and Management, Kenyatta University P. O. Box 43844-00100, Nairobi, Kenya2Kenya Agricultural and Livestock Research Organization, P.O. Box 340 – 90100 Machakos

Corresponding author: wanjala2002@gmail.com; 0720364747

AbstractIntegrated soil fertility management practices (ISFM) in the recent past have been promoted as the best option towards improving soil productivity, however, little evidence exist confirming if the adopters meet the requirements stated in principles of ISFM. A survey was conducted in Mwania watershed located in Machakos, Eastern Kenya in 2016, to establish the prospects of using ISFM practices in reversing soil nutrient depletion and increasing crop yields. The survey was conducted using a structured questionnaire, key informants’ interviews, and focus group discussions. Data collected from 175 households head (HHHs) included evidence on use of insitu water harvesting structures, soil fertility practices, land tenure and history of crop yields. Data was analysed using the Statistical Package for Social Sciences (SPSS) Version 22 computer program. The results showed 60 % of the households owned and intensively cultivated less than 2 hectares of land with little or no soil nutrient restitution. Legume and cereal yields obtained seldom surpasses 0.5 and 0.8 t ha-1 respectively. Majority 80% of households had adopted legume-maize intercropping, in situ water harvesting, manure and chemical fertilizers but they were using them independently because of diverse household adaptive power and high input cost. Most of respondents 83%, intensively cultivated < 2 ha with little of no external soil nutrient replenishment and cereal and legume yields seldom exceeding 0.68 and 0.29 t ha-1 respectively. Therefore, occurs huge potential of upscaling appropriate ISFM practices in entire community of Mwania watershed.

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Sustainable increase of maize production using potassium fertilizer for enhancing Food Security in KenyaS.K. Kimani (1) *, Gikonyo, E.W. (1), C.N. Kibunja (1), A.O. Esilaba (1), Kamau, D.M. (1) P.N.M Njeru and L.W. Mbuthia(2)

(1)Kenya Agricultural and Livestock Research Organization, (KALRO-Muguga), Nairobi, Kenya(2)IPI Coordinator for Eastern Africa, International Potash Institute (IPI), Zug, Switzerland

*Corresponding author: stephen.kimani@kalro.org

AbstractMaize is the most important staple in Kenya, and is grown across a wide range of agro-ecological zones, accounting for about 40 percent of daily calories. A major constraint in maize production in Kenya is low and declining soil fertility. Nutrient input and output studies on farmlands across Kenya and sub-Saharan Africa show an alarming negative balance leading to widespread land degradation. This study sought to increase maize yield through application of potassium and lime in western Kenya. The field experiments are conducted at Bungoma and Trans Nzoia counties in western Kenya, considered the breadbasket region for the country. The objectives were to establish maize responses to K fertilization and to evaluate maize responses to different potash sources, with and without lime. The study also aimed at applying coated N fertilizer compared with top-dressed N. In a second experiment, the study explored the effects of three different K fertilizers on maize yields. At Bungoma, liming increased stover yields by 70% from 2.4-4.3 t/ha. Bungoma, maize yields ranged from 2.2-4.5 t/ha in Mabanga and 3.6-6.2, with optimal response to K at 40 kg/ha at Ndengelwa and 80 kg/ha at Mabanga sites. In Trans Nzoia, liming treatment stratum was significantly different at 5% level. Overall, liming increased stover yields by 17%. At 40 kg K application, liming increased stover yields by 50% (6.3-9.5 t/ha), whilst under no liming, 40 kg/ha K application increased stover yields by 30% at 5.4-6.9 t/ha. Our work confirms that soils in western Kenya are acidic and have low levels of K. This requires liming and NPK fertilization. Our results indicate responses to K fertilization, as well as benefits realized through controlled release N fertilizer.

Different potash fertilizers increase maize yields in Trans Nzoia and Bungoma Counties in Western KenyaS.K. Kimani(1) *, Gikonyo, E.W.(1), C.N. Kibunja(1), A.O. Esilaba(1), Kamau, D.M. (1) PNM Njeru(1)* and L.W. Mbuthia(2)

(1)Kenya Agricultural and Livestock Research Organization, (KALRO-Muguga), Nairobi, Kenya (2)IPI Coordinator for Eastern Africa, International Potash Institute (IPI), Zug, Switzerland

*Corresponding author: peterson.njeru@kalro.org

AbstractMaize is the most important staple in Kenya, and is grown across a wide range of agro-ecological zones, accounting for about 40 percent of daily calories. Approximately 3.5 million small-scale farmers are involved in maize production accounting for 75% of the total maize crop while

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1,000 large-scale farmers produce the remaining 25% of the production. Annual Per capita consumption of maize in Kenya is estimated at 98 kilograms which translates to between 30 and 40 million bags of maize annually. Over the years, production has fallen behind the national demand for maize, and the deficits have had to be met through imports. A major constraint in maize production in Kenya is low and declining soil fertility. Nutrient input and output studies on farmlands across Kenya and sub-Saharan Africa show an alarming negative balance leading to widespread land degradation. This study explored the effects of three different K fertilizers on maize yields. The work was carried out in Trans Nzoia and Bungoma counties of western Kenya. The three sources of K were Potassium sulphate (KS), muriate of potash (MOP) and triple seventeen (SSS). The experimental design was a randomized complete block design with four replicates. In Trans Nzoia, the three sources of K significantly increased maize yields to 10-15 t/ha. KS and MOP had slightly higher yields, though not significantly different. At Bungoma, yields were lower at (3-11 t/ha). Within farms, there were no significant differences in the three fertilizer sources of K.

Anthill soil utilization in maize cropping systems: an endogenous soil fertility management practice by smallholder farmers in Zambia Kafula Chisanga1,2, Ernest R. Mbega1, Patrick A. Ndakidemi1,2

1Department of Sustainable Agriculture, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania2Centre for Research, Agriculture Advancement, Teaching Excellence and Sustainability (CREATES) in Food and Nutrition Security, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania

*Corresponding author: chisangak@nm-aist.ac.tz

AbstractTwo districts of Zambia namely; Choma and Pemba were surveyed. The overall objective of the study was to get farmer perceptions of anthill soil utilization practices for key information that would contribute towards the development of anthill soil based research agenda. The study employed both qualitative and quantitative methods approach to collect data from the respondents that included farmers and key informants who had the knowledge about anthill soils in crop production. Qualitative data was analyzed using triangulation method and Computer Assisted Qualitative Data Analysis Software (CAQDAS), Nvivo version 10 while data generated from quantitative interviews with a Smart phone Application (Open Data Kit) was analyzed using Statistical Package for Social Sciences (SPSS). Results revealed that the major key hurdles to the application of anthill soil lay in biophysical, technological, land, institutional and agro-climatic constraints. Largely farmers reported poor rainfall patterns (94.62 %), decreasing soil fertility (69.74 %), limited farm products (69.23 %), finance (66.41 %), limited access to research and extension services (54.62 %) as key constraints confronted on their farms coupled with security of land tenure (48.21 %). We, therefore, advocate for strengthened social networks of the smallholder farmers for them to have access to information on the efficient approach of utilizing anthill soil technology. Enhancing institutional linkages between research and extension is critical for information dissemination which would aid in decision making for farm operations.

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Evaluation of the soil fertility status and limiting nutrients for Maize Production in KenyaJ. A. Omwakwe a*, Prof George N. Chemining’wab, Dr. A.O. Esilaba c, EG Thuraniraa

a Kenya Agricultural and Livestock Research Organization, Kabete. P.O Box 14733-00800 Nairobi Kenya. b Department of Plant Science and Crop Protection, University of Nairobi, P. O. Box 29053-00625, Kangemi. c Kenya Agricultural and Livestock Research Organization, Headquarters. P. O. Box 57811, City Square, Nairobi, 00200 Kenya.

*Corresponding author:addahjoyce@yahoo.com

AbstractMaize is the staple food for most Kenyan households, however over the decades maize yields have decreased or remained stagnant. This is partly attributed to poor soil fertility and soil heterogeneity, despite much work been done to tackle soil fertility issues. This has however led to investigation of individual nutrients to determine their limitation in different soil types. To investigate this, 23surface soils (0 to 30 cm) were collected from 13 counties in Kenya and a nutrient omission trial was set up in the greenhouse at the Kenya Agricultural and Livestock Research Organization Kabete. The objective was.to assess the limiting nutrients in the soil and evaluate the response of maize to applied nutrients. The experiment was laid out in a completely randomized design with 12 treatments; complete (all macro and micro nutrients), complete plus lime, five treatments where one macro nutrient was omitted from the nutrient solution, one treatment where the micro-nutrient mixture was omitted from the nutrient solution, one treatment with all the micro nutrients except zinc, the other with all micronutrients except boron, one treatment with all the micro nutrients except molybdenum and one control (distilled water only). Significantly (P<0.05) lower dry shoot dry weights than the complete treatment were observed in most of the soils. The results showed that poor maize growth was mainly due to omission of nitrogen, phosphorous, zinc, molybdenum and micronutrients. An addition of nutrients, improved the yield relative to the control in most soils, as most of the controls were limiting. The ability to rapidly assess the nutrient supplying capacity of soils is an essential first step in developing useful nutrient management systems. Research should focus on laboratory, greenhouse and field trials, to correlate and calibrate the plant availability of macronutrients and micronutrients for site specific smart fertilizer recommendations in Kenya.

Potassium based fertilizer on green grams and millet yields in Embu and Tharaka-Nithi countiesMicheni A1., Kinuthia P1., Njagi I1., Esilaba A2., Muriithi S1. , Thuranira E3., Gicheru P1. & Nyongesa D3.1Kenya Agricultural and Livestock Research Organization (KALRO-Embu), P.O. box 27-60100, Embu

2Kenya Agricultural and Livestock Research Organization (KALRO Headquarters), P.O. box

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57811-00200, Nairobi3Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. box 66730-00800, Nairobi*Corresponding author: alfred.micheni@kalro.org

AbstractThe study was conducted to determine the appropriate amount of potassium (K) fertilizer (in form of muriate of potash on grain yields of peal millet and sorghum in Embu and Tharaka-Nithi Counties. Treatments were arranged in split–plots in a complete randomized block design (RCBD) with two factors and three replicates. Factor I: crops= Millet (KPM 3 variety) and sorghum (Gadam variety); Factor II: K fertilizer dose consisting of seven rates (including absolute zero input) or Nil. Potassium was applied to the crops at seeding time at varying rates. The K fertilizer dose (40 – 200 kg ha-1) increased the yields of millet and sorghum, particularly in Embu County. Further analysis indicated that the K fertilizer applied at 80kg ha-1 K2O as the most effective rate for the two crops. This rate may even be the most cost effective in the two Counties. Thus, more studies needed to define the ecology, economics and crops needs for different rates of K based fertilizers.

Effects of blended NPK fertilizer sources and rates on growth and yield of maize in Kirinyaga County, Central KenyaP.W. Mwangi, J.M. Miriti* and E.M. Muriuki

Kenya Agricultural and Livestock Research Organization, Food Crops Research Institute, National Agricultural Laboratories Kabete, P.O. Box 14733-00800 NAIROBI.

*Corresponding author: jmmiriti2008@gmail.com

Abstract The genetic potential of existing maize varieties has not been fully exploited in many areas of Kenya mainly due to the low and declining soil fertility. Although fertilizers can improve soil fertility, crop response to conventional mineral fertilizers is low because they lack important secondary nutrients such as sulphur (S), Calcium (Ca), boron (B), zinc (Zn), manganese (Mn), and copper (Cu) required for optimum crop growth. A study was conducted for two season (2012 Long rains and Short rains seasons) in Central Kenya to compare the effect of two blended fertilizers (10N+26P+10K+5S+14CaO+4MgO+ Traces and 26N+0P+0K+5S+10CaO) that contain secondary and micronutrients with compound fertilizers diammonium phosphate (DAP) and calcium ammonium (CAN) on the growth and yield of maize. Fertilizers application rates were 50, 100, 150 and 200 kg/ha. The highest maize growth (plant height and leaf area index) and yield (seed size, cob length and grain yield) parameters were observed in maize grown with fertilizer blends supplying nitrogen (N) phosphorus (P) and potassium (K) at 82, 52, 20 kg /ha (or application of blended fertilizer at 200 kg/ha), respectively. There were no significant differences between blended fertilizers and DAP/CAN in their influence on maize growth and yield parameters when they were applied at the same rates. The treatment with NPK (10:26:10)+5S+14CaO+4MgO+5 trace plus 26:0:0+5S+10CaO (200kg/ha) had however the highest grain yield (6732.7 and 7154.5 kg/ha in the LR and SR season, respectively) while the lowest grain yield was observed

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in plots that did not receive any fertilizer. Higher agronomic nitrogen and phosphorus use efficiencies were recorded in maize grown with fertilizer blends compared to maize grown with compound fertilizers (DAP/CAN combinations). Nitrogen and Phosphorus use efficiencies of maize diminished as fertilizer application rates increased in both growing seasons. In general, relative to the control, percentage increase in both growth and yield parameters were higher when maize was grown with blended fertilizers compared to compound fertilizers (DAP/CAN application). The study demonstrated that blended fertilizers have the potential to improve maize yields in central Kenya.

Strong spatial-temporal patterns in maize yield response to nutrient additions in Western Kenya Samuel Njorogea,b,*, Antonius G.T. Schutb, Ken E. Gillerb, Shamie Zingorea, Joses Muthamiaa

aInternational Plant Nutrition Institute, ICIPE Compound, Box 30772, Nairobi, KenyabPlant Production Systems, Wageningen University, P.O. Box 430, 6700AK, Wageningen, The Netherlands

*Corresponding author: snjoroge@ipni.net

Abstract Large variability in crop responses to macronutrient application at various spatial scales present challenges for developing effective fertilizer recommendations for crop production in smallholder farming systems of sub-Saharan Africa. We assessed maize yield responses to nitrogen (N), phosphorus (P) and potassium (K) application and evaluated relationships between crop responses to N, P and K application and soil analysis data. Nutrient omission trials were conducted on 23 farms located in Sidindi, Western Kenya, selected to be representative of the main soil and management factors in maize based systems in Siaya County. Treatments included a control and PK, NK, NP and NPK applications. The trials ran for six consecutive cropping seasons, without changing treatments or plot location, covering the period 2013–2015. Strong spatial-temporal patterns in maize yield responses to N, P and K applications were observed. Average maize yields in the control, PK, NK, NP and NPK treatments were 2.8, 3.2, 5.1, 5.1 and 5.5 t ha-1 at 88% dry matter respectively in the first cropping season, and 1.1, 1.4, 2.9, 3.6 and 5.3 t ha-1 at 88% dry matter respectively in the sixth cropping season. In all seasons, variability in maize yield between fields was greatest in the control treatment followed by the NK treatment and least in the NPK treatment. Mean relative yield was 0.6, 0.92 and 0.93 for N, P and K respectively, in the first cropping season, and 0.25, 0.52 and 0.68, respectively, in the sixth cropping season. Six main maize yield response categories were identified that differed in the maize grain yield responses to recursive N, P and K applications. Maize yield responses to N, P and K were not fully accounted for by soil organic matter, soil available P and exchangeable K respectively. Our results indicate that current methods for soil analysis do not adequately predict the response to application of N, P and K fertilizer under the highly variable soil fertility conditions encountered in smallholder farming systems. The strong spatial-temporal patterns observed present major challenges for the development of effective site-specific fertilizer recommendations. Potential avenues for future research and options for more effective intensification strategies are discussed.

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Maize Hybrid Response to Rates and Timing of Basal Phosphate Application in an Acidic Ferralsol of North Rift KenyaNdung’-Magiroi, K.W. uand Kifuko-Koech, M.N.

Kenya Agricultural and Livestock Research Organization, Food Crops Research Institute (KALRO- FCRI) P.O. Box 450, Kitale 30200

Corresponding author: keziahmagiroi@gmail.com AbstractAn on-farm trial was conducted to assess the effect of timing and rate of basal fertilizer application on two KALRO maize hybrid varieties in acidic soils. Treatments were assigned to a split-split plot structure arranged in a completely randomized block design replicated seven times in four farms. Main plot consisted of time of phosphorus (P) application (0 and 3 weeks after planting- WAP), while varieties (K614D and KH 600-16A) were assigned to sub plot and fertilizer rates (0, 7, 13, 26 kg P/ ha and CAN at 60 kg N/ha) to the sub-sub plots. Results showed that maize yields increased with increasing rates of P, but no varietal effect was noted. Application of basal fertilizer as DAP or CAN gave significantly (p=0.05) higher maize grain yields compared to the control. The recommended fertilizer rate (26 kg P/ha) produced the highest grain yields that were 140% higher than the control (no fertilizer). Agronomic P use efficiency significantly increased with decreasing rates of P application, with the highest increase noted in 7 kg P /ha applied 3WAP. Based on grain yield and increased nutrient use efficiency, it was concluded that application of 7kg P/ha DAP at 3WAP could be more appropriate dose of P for maize for farmers who may not afford the recommended rate.

Potassium response in maize at Bungoma and Trans Nzoia counties western KenyaS.K. Kimani(1) *, Gikonyo, E.W.(1), C.N. Kibunja(1), A.O. Esilaba(1), Kamau, D.M. (1) and L.W. Mbuthia(2)

(1)Kenya Agricultural and Livestock Research Organization, (KALRO-Muguga), Nairobi, Kenya (2)IPI Coordinator for Eastern Africa, International Potash Institute (IPI), Zug, Switzerland

*Corresponding author: stephen.kimani@kalro.org

AbstractMaize is the most important staple in Kenya, and is grown across a wide range of agro-ecological zones, accounting for about 40 percent of daily calories. A major constraint in maize production in Kenya is low and declining soil fertility. Nutrient input and output studies on farmlands across Kenya and sub-Saharan Africa show an alarming negative balance leading to widespread land degradation. This study sought to increase maize yield through application of potassium and lime in western Kenya. The field experiments are conducted at Bungoma and Trans Nzoia counties in western Kenya, considered the breadbasket region for the country. The objectives were to establish maize responses to K fertilization and to evaluate maize responses to different potash sources, with and without lime. The study also aimed at applying coated N fertilizer compared with top-dressed N. In a second experiment, the study explored the effects of three different K fertilizers on maize yields. At Bungoma, liming increased stover yields by 70% from 2.4-4.3 t/ha. Bungoma, maize yields ranged from 2.2-4.5 t/ha in Mabanga and 3.6-6.2, with optimal response to K at 40 kg/ha at Ndengelwa and 80 kg/ha at Mabanga sites. In

56

Trans Nzoia, liming treatment stratum was significantly different at 5% level. Overall, liming increased stover yields by 17%. At 40 kg K application, liming increased stover yields by 50% (6.3-9.5 t/ha), whilst under no liming, 40 kg/ha K application increased stover yields by 30% at 5.4-6.9 t/ha. Our work confirms that soils in western Kenya are acidic and have low levels of K. This requires liming and NPK fertilization. Our results indicate responses to K fertilization, as well as benefits realized through controlled release N fertilizer.

Effects of phosphorus levels on bush bean and climbing bean productivity in greenhouse under low nitrogen sand J.G.N. Muthamia1 P.M. Kimani2 G.C. Chemining’wa2, A.O. Esilaba3 C. Kibunja4

1KALRO-Embu, P.O. Box 27, 601002University of Nairobi, P.O. Box, 290533KALRO-HQ. P.O. Box 57811 Nairobi4KALRO-NARL P.O. Box 14733 00800

*Corresponding Author: muthamiajohn@yahoo.com

AbstractA split plot designed greenhouse trial to monitor the influence of phosphorus levels (0, 25, 50 and 75 kgha-1 P) on three bean varieties (Mwende, GLP2 and non nodulating reference variety Bat477nn) supplied with labelled N15 as starter Nitrogen at 20 kgha-1 and also to help in quantifying N-fixation was carried out at Kabete Field Station.. The data collected included chlorophyll content measurements (SPAD) at Wooteekly intervals, nodule number and nodule dry weight per plant at flowering stage, root and shoot biomass, plant tissue analysis for N15 excess, total N for foliage and roots. Statistical data analyses was done using a Genstat statistical package. Results showed that both bush test varieties (Mwende and GLP2) optimized N-fixation at 25 kgha-1 P and additional P suppressed N-fixation. Mwende fixed more nitrogen by 83% over GLP2 at peak fixation. It was also observed that by the end of three weeks after inoculating the seedlings, nitrogen fixation was evident. Increased P continued to increase nodulation in both commercial varieties with more nodules in Mwende. It was also observed that as P was increased there was a corresponding non statistical increase in shoot biomass and a corresponding statistical significance of decline in root biomass. These observations lead to the conclusion and recommendation that the optimum levels of P for bush bean growth should be 25-50 kgha-1 P.

Effect of Application of Blended Fertilizers on Biomass and Grain Yields of Sorghum and Pearl Millet Under Rain-fed Condition in Kitui County, Eastern Kenya.David Macharia1*, Daniel Mutisya1, Emerita Njiru1, Anthony Esilaba2, Angela Kathuku-Gitonga3, Dave Nyongesa3, Elias Thuranira3, Micheal Okoti3 and Simon Nguluu4

1Kenya Agricultural and Livestock Research Organization, KARLO Katumani. P.O Box 340-90100 Machakos, Kenya.2Kenya Agricultural and Livestock Research Organization, KALRO Headquarters. P.O Box 57811-00200 Nairobi, Kenya

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3Kenya Agricultural and Livestock Research Organization, KARLO Kabete. P.O Box 14733-00800 Nairobi, Kenya4South Eastern Kenya University, Main Campus. P.O Box 170-90200 Kitui, Kenya.

*Corresponding Author: davriba@gmail.com

AbstractSorghum (Sorghum bicolor (L.) Moennch) and Pearl millet (Pennisetum glaucum (L.) R. Br.) are important cereal crops and stable food for the semi-arid small scale farming communities in Kenya. Despite their importance, their yields are limited by different factors including declining soil fertilizer and improper utilization of fertilizer. Results of the research conducted in South Eastern Kenya University during the cropping season of 2017-18 are presented in this paper. The aim was to investigate the effect of blended fertilizers on total biomass and grain yields of sorghum and pearl millet. The experiment was set up in a completely randomized block design with a split plot arrangement with crops (sorghum and pearl millet) as the main plots and six blended fertilizers (DAP, Mavuno (Cereal planting), MEA Mazao, Minjingu (Nafaka Plus), NPK 17:17:17 and NPK 23:23:0) and the control (no nutrient input) as the subplots. The trail was replicate four times. The results indicate that there was a significant interaction effect of fertilizer treatments and sorghum variety on the two parameters studied. The use of NPK 23:23:0 blended fertilizer recorded the highest total biomass yield (6.61 t ha-1), and grain yield (0.88 t ha-1) in sorghum and was closely followed by application of DAP. The results also revealed that application of different fertilizer blends significantly affected the total biomass and grain yields of pearl millet. Highest pearl millet total biomass was obtained from the application of NPK 23:23:0, while application of MEA Mazao ranked second for total biomass. Application of NPK 23:23:0 recorded the highest pearl millet grain yield and was statistically similar to the use of Mavuno.

Evaluation of Maize Varieties under Two Fertilizer RegimesKamidi M.1, E, Wanjekeche1, M. Koech1, Mutoko1, K. Ndung’u1 J. Barkutwo1, J. Wanyama1, V. Ouma1 A.O Esilaba3, M. Okoti3, E, Thuranira2, L. Wasilwa3, C. Githunguri2, D. Nyongesa2, J. Miriti2

1 Kenya Agricultural Research Institute (KALRO)-Kitale, P. O. Box 450-30200, Kitale2 KALRO-NARL, P. O. Box 14733-00800, Kabete3 KALRO-Headquarters, P. O. Box 57811-00200, Nairobi.

*Corresponding Author: kamidimargaret@yahoo.co.uk

AbstractThis study was undertaken during 2016 and 2017 to demonstrate and expose farmers to ten high yielding maize varieties for them to observe performance, adopt them, increase yield hence food security and income. The maize was planted with and without fertilizer. At KALRO Kitale, the differences in grain yield among the varieties were significant (P<0.5), in both years. Varieties H6213 and H629 were among the top three varieties for yield in both years. No significant differences (P>0.5) were observed in grain yield on-farm in Trans Nzoia during both years. Lime had no effect on the yields of maize during 2016. There were significant differences

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(P<0.05) in biomass production among varieties both on-station and on-farm. A range of 5.76 t/ha was observed on-station between H6218 with the highest biomass and Pioneer the lowest and 7.08 t/ha on-farm between H6210 and the lowest H614D. H6210 had the lowest number of rotten cobs compared to PAN691, Pioneer, and H614D that had the highest.In Nandi county, there were significant differences (P<0.5) in maize yield in both years on station and on-farm in 2016. Hybrids H6213 and H6210 were among the top three varieties for yield overall. There was no significant response to fertilizer in the first year but significant differences (P<0.5) were observed in 2017 at all sites. No significant difference was observed in the number of rotten cobs. In 2017 fertilizer increased biomass production on-farm by 2.53 t/ha in Trans Nzoia and 2.59 t/ha in Nandi. Overall increment on-station was 2.76 t/ha and 1.58 t/ha at KALRO Kitale and Baraton respectively. There were no significant differences in both harvest indices among varieties in all sites. Seed density range among varieties was only 0.0085 g/100 in Trans Nzoia and 0.007 g/100 in Nandi.

Selection Process of Performing Integrated Soil Fertility Management (ISFM) Technologies for Enhanced Maize Production in KenyaN. Mangale1, A. N. Kathuku-Gitonga1, A. W. Muriuki1 and J. K. Mutegi2

1Kenya Agricultural and Livestock Research Organization, Kabete, P. O. Box 14733 – 00800, Nairobi, Kenya 2International Plant Nutrition Institute, ICIPE Compound, P. O. Box 30772 – 00100, Nairobi, Kenya

Abstract Per capita food production in Kenya has continued to decline in spite of the successful introduction of new crop varieties, associated fertilizer and pesticide packages coupled with excellent research outcomes. Natural disasters (increased incidences of floods and droughts) and degradation of the soil resource base among others have been cited as the main reasons for the decline. Degradation of the soil resource base is directly linked to poor land management including land use without installation of appropriate erosion control measures and exportation of nutrients from farms through the crop harvests without adequate replenishment of the removed nutrients. Additional soil fertility information showed that most farmed soils were deficient in organic matter and are acidic. The decreased soil organic matter and widespread soil acidity is due to prolonged removal of crop residues, limited use of good quality organic manure and injudicious use of inorganic fertilizers. The traditional way of maintaining soil fertility through shifting cultivation, application of sub-optimal amounts of mineral fertilizers and/or manure and inclusion of grain legumes into the cropping systems is not sufficient to meet crop nutrients demands and ensure food security in the country. A large body of research to this effect is available such as the crop-soil and agro-ecological zone specific fertilizer recommendation developed by the Fertilizer Use Recommendation Project (1989 to 1994) and verified through the Fertilizer Extension Project (1994 to 1999), limiting nutrient trials carried out by Tropical Soil Biology and Fertility Institute (1990’s to 2000’s) and within the last decade the International Plant Nutrition Institute (IPNI) and Alliance for a Green Revolution in Africa (AGRA).The results from these research efforts support combined use of organic and inorganic

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fertilizers popularly known as Integrated Soil Fertility Management (ISFM), which has proved to restore the soil resource capital base and significantly increase crop yields. However these technologies are in agronomic published form in journals, PhD and MSc theses and technical reports. They are thus not accessible to farmers and other end users. Even if they may be accessible to the end users, they are written in scientific language that only researchers and academia can understand them. This paper features the process of selecting and simplifying performing Integrated Soil Fertility Management (ISFM) Technologies from ISFM research legacy data collected in Kenya for use by targeted audience to enhanced maize production in the country.

Sulphur Nutrition in Crop Production Research in Kenyan: A ReviewN. Mangale1*, A.O. Esilaba2, A. N. Kathuku-Gitonga1, D. Nyongesa1 and L. Wasilwa2

1Kenya Agricultural and Livestock Research Organization, Kabete, FCRI, P. O. Box 14733 – 00800, Nairobi, Kenya2Kenya Agricultural and Livestock Research Organization, Headquarters P. O. Box 57811 – 00200, Nairobi, Kenya

AbstractSulfur (S) is an essential nutrient in crop production. It is classified as a secondary element, along with Magnesium and Calcium, but it is sometimes called “the 4th major nutrient”. Some crops can take up as much S as Phosphorus. Sulfur has become more important as a limiting nutrient in crop production in recent years for several reasons. These include higher crop yields that require more S, less S impurities in modern fertilizers, less use of S-containing pesticides, reduced industrial S emissions to the atmosphere, and a greater awareness of S needs.Sulfur serves many functions in plants. It is used in the formation of amino acids, proteins, and oils. It is necessary for chlorophyll formation, promotes nodulation in legumes, helps develop and activate certain enzymes and vitamins, and is a structural component of two of the 21 amino acids that form protein.The majority of S in most soils is contained in organic matter. Organic S must be mineralized to the inorganic sulfate anion (SO4

-2) before it can be taken up by crops. Organic matter decomposition and the resulting S release is affected by temperature and moisture, and generally conditions that favor crop growth also favor mineralization and release of S. Sulfate, like most anions, is somewhat mobile in soils and therefore subject to leaching. Soil conditions where S is most likely to be deficient are low organic matter levels, coarse (sandy) textured soils with good drainage, and high rainfall conditions. But, these are generalizations and S can be deficient under other conditions as well.Sulfur, though widely deficient in Africa, has received little attention by soil fertility researchers. Shifts to low-S, high-analysis fertilizers, continuous cropping, and higher-yielding varieties may have increased S limitations in crop production. The efficiency of applied high-analysis fertilizers such Urea, Di-ammonium phosphate (DAP), Triple superphosphate (TSP), Calcium ammonium Nitrate (CAN) NPK and others together with the economics of their use are seriously affected under sulphur deficient conditions. Hence, higher crop yields may not be

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sustained. This essay should encourage decision-makers to take more care about this essential element.Effect of Tillage, Liming and Cropping Systems on Maize Yields during the Long Rains Season in Different Agroecological Zones in Western Kenya1C. M. Githunguri, 2A. O. Esilaba, 2M. Okoti, 1E. Mutuma, 1J. Miriti, 1D. Nyongesa, 1E. Thuranira, 3M. Koech, 3C. Mutoko, 3K. Ndungu, 4P. Ooro, 4P. Ketiem, 4H. Mwangi, 5V. Woyengo, 5M. Odendo, and 5G. Ashiono

1Kenya Agricultural and Livestock Research Organization (KALRO), Food Crops Research Centre Kabete, Nairobi, P.O. Box 14733– 00800; Tel: 0726959592; 020-2464435; Email: cyrusgithunguri@yahoo.com; 2KALRO Headquarters, P. O. Box 57811-00200, Nairobi 3KALRO- Kitale, P. O. Box 450-30200, Kitale4KALRO – Njoro, Private Bag (20107) Njoro 5KALRO – Kakamega. P.O.BOX 169 – 50100, Kakamega

*Corresponding Author: cyrusgithunguri@yahoo.com

AbstractClimate change is estimated to contribute to reduced global yields of maize. There is therefore need to endow farmers with innovative and transformative climate smart agriculture technologies to urgently address food insecurity and the realities of climate change in cereal growing regions of Kenya. Technologies have been generated for improved maize and beans production whose impact has not been fully felt. In this study technologies and innovations on tillage, liming and cropping systems that can improve maize and beans production were evaluated and demonstrated to farmers in different agroecological zones in western Kenya with the aim of enhancing their adoption. Trials were established at KALRO-Njoro, KALRO-Kakamega, KALRO-Kitale, Baraton University, and Mabanga Agricultural Training Centre, in Nakuru, Kakamega, Trans-Nzoia, Nandi, and Bungoma Counties, respectively. The tillage treatments evaluated included conventional, tied ridges, minimum and zero tillage planted in plots applied with two tons ha-1 of lime or without lime. The cropping systems evaluated were maize intercropped with beans or sole cropped maize. A split-split plot design with four replications was used. Data was collected on yield, analysed for variance, and treatment means separated using least significant difference. In Nakuru, Nandi and Trans-Nzoia Counties the plots under conventional, tied ridges, and minimum tillage produced significantly higher yields than the zero tillage with or without lime irrespective of the cropping system used, even though, plots treated with lime in Nandi County produced significantly higher yields than those without. In the Kakamega and Bungoma Counties, there were no significant differences between the four tillage systems. The liming and cropping effects on maize yields were not significant in Nakuru, Nandi, Trans-Nzoia, Kakamega, and Bungoma Counties irrespective of the tillage method used. The tillage effects on maize yields were not significant in Nandi, Kakamega, and Bungoma Counties irrespective of the cropping system used.Evaluation of Fertilizer Sources and Efficacy on Maize Production in Western Kenya1C. M. Githunguri, 2A. O. Esilaba, 1E. Mutuma, 2M. Okoti, 1J. Miriti, 1D. Nyongesa, 1E. Thuranira, 3M. Koech, 3C. Mutoko, 3K. Ndungu, 4P. Ooro, 4P. Ketiem, 4H. Mwangi, 5V. Woyengo, 5M. Odendo, and 5G. Ashiono

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1Kenya Agricultural and Livestock Research Organization (KALRO), Food Crops Research Centre Kabete, Nairobi, P.O. Box 14733– 00800; Tel: 0726959592; 020-2464435; Email: cyrusgithunguri@yahoo.com; 2KALRO Headquarters, P. O. Box 57811-00200, Nairobi 3KALRO- Kitale, P. O. Box 450-30200, Kitale4KALRO – Njoro, Private Bag (20107) Njoro 5KALRO – Kakamega. P.O.BOX 169 – 50100, Kakamega

AbstractStudies conducted in western Kenya showed that the response of maize to the application of the different nutrient sources and amendments varied with the soil with maize responding differently to application of all the sources of nutrients and amendments. Blended fertilizers are simple physical mixtures of dry fertilizer materials such as urea or potassium chloride. Some fertilizer blends contribute to increased soil acidity which in the long run may lead to low soil fertility due to nutrient fixation and eventually to low maize yields. Some of these fertilizers could also expensive when considered on the basis of the quantities of plant nutrients they supply. Consequently trials to evaluate and demonstrate the efficacy of the plant nutrients available in the diverse fertilizer sources and lime in central Rift Valley and Western regions of Kenya were established in Nakuru, Nandi, Trans Nzoia, Kakamega, and Bungoma counties during the 2017 long rains season. Maize supplied with Mavuno and DAP fertilizers produced significantly higher yields than those grown with MEA Mazao, Minjingu and NPK 23:23:0, while those grown without fertilizer (nil) had the lowest yield. Application of lime did not significantly influence grain yield in Nakuru, Nandi, Kakamega and Bungoma Counties. All sources of fertilizer did not significantly influence grain yield of maize irrespective of lime and no lime application in Kakamega and Bungoma Counties. In Nandi and Trans Nzoia Counties, maize planted with DAP, Mavuno, MEA Mazao, and NPK 23:23:0 fertilizers produced significantly higher yields than those grown with Minjingu while those grown without fertilizer (nil) had the lowest yield. Maize grown with lime produced significantly higher maize yields than those without lime irrespective of source of fertilizer in Trans Nzoia County. There were no significant yield differences between maize planted with or without liming. In addition, those planted with lime produced slightly higher yields than those without lime irrespective of fertilizer source. Across all five Counties, maize planted with DAP, MEA Mazao, Mavuno, and NPK 23:23:0 fertilizers produced higher yields than those grown with Minjingu and without fertilizer (nil) with or without lime application. Generally it seems DAP, Mavuno, NPK, and MEA Mazao sources of fertilizer are ideal for all Counties irrespective of the liming regime and as such, farmers should make informed decision on fertilizer use based on nutrient content, cost of applied nutrient and economic returns from the fertilizer.

Effect of different zinc fertilizer rates and cropping systems on recommended maize and beans grown in western KenyaCyrus M Githunguri1∼, A. O. Esilaba2, Joseph M Miriti1, M. Okoti, Elias G Thuranira1, Mary N Koech3, Keziah W Ndungu3, C. Mutoko3, M. Kamidi3, J. Barkutwo3, Vincent W Woyengo4, Gerald Ashiono4

*Corresponding Author: cyrusgithunguri@yahoo.com

1Kenya Agricultural and Livestock Research Organization (KALRO), Food Crops Research Centre Kabete, Nairobi, P.O. Box 14733– 00800;

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2KALRO Headquarters, P. O. Box 57811-00200, Nairobi3KALRO- Kitale, P. O. Box 450-30200, Kitale.4KALRO – Kakamega. P.O.BOX 169 – 50100, Kakamega

AbstractMicronutrients like zinc (Zn) are involved in the key physiological processes of photosynthesis and respiration and their deficiency can hamper these crucial physiological processes and thus curtailing yield gain. Dry beans and maize are sensitive to Zn deficiency with early deficiency symptoms manifesting as mild interveinal yellowing and leaf deformation on new leaves and eventually progressing necrotic spots, with leaf margins appearing lighter in colour than the interior of the leaf. Micronutrient requirements depend on plant uptake, soil availability and growing seasonal conditions. Several soil conditions could lead to development of Zn deficiencies, which can reduce yields and delay crop maturity. Zinc has important functions in protein and carbohydrate metabolism. The main function of zinc is catalytic, playing a role in building and activating plant enzymes and as such its deficiency can be critical. Currently several different Zn sources, including ZnSO4, ZnCO3, ZnO, Zn (NO3)2 and ZnCl2 are being used as fertilizers. It is therefore important to explore management options that could enhance the performance, quality and yields of maize and bean crops using zinc. As such, the objective of the study was to demonstrate the effect of zinc fertilizer on the performance of maize and beans grown in Nandi, Trans Nzoia, and Kakamega counties in western Kenya. The study was conducted under field conditions in Nandi, Trans Nzoia, and Kakamega counties during the main rain season of 2017. Different zinc fertilizer rates on recommended maize and beans grown in western Kenya were tested under optimum (with recommended rate of fertilizer) and low input (zero fertilizer) management. The different zinc fertilizer rates and two cropping systems were laid out in a randomized complete block design (RCBD) in a factorial arrangement with four replications. The zinc fertilizer was assigned as the main plot while the cropping system formed the sub-plot. During the study, all recommended cultural practices were carried out and the crops harvested at physiological maturity. Grain samples were oven-dried at 650C to attain 12.5% moisture content. Data was analysed following analysis of variance procedure in SAS software. Treatment means were separated using least significant difference at 5% level of significance. There were no significant differences (p ≤ 0.05) in beans and maize grain yield planted under different zinc fertilizer rates and with or without Zn fertilizer across the three counties. Similarly, there were no significant differences (p ≤ 0.05) in maize grain yield planted either as a mono crop or intercropped with beans across the three counties. However, beans planted as a mono crop produced significantly higher grain yield (p ≤ 0.05) than those intercropped with maize across the three counties. There could be some interactive effects between zinc and cropping system that could be inhibiting uptake of Zn by beans and maize plants in the three sites. Lack of significant response to Zn application could be an indication that Zn was adequate in these farms. This study therefore propose that application of Zn based fertilizers in maize and bean crops is not necessary in the Nandi, Trans Nzoia, and Kakamega Counties sites. This study also suggests that when maize is the targeted crop it should be grown either as a monocrop or intercropped with beans. However, when bean production as the targeted enterprise, then it should be grown as a monocrop to achieve maximum yields. Finally, due to the nutritional importance of Zn there is need to conduct plant uptake of this element by both bean and maize grains.

Effect of seed treatment on Ridomil® application frequency in managing potato late blightKilonzi, J.M1*, Mafurah, J.J2, and Nyongesa, M.W3

1,2Egerton university, Department of Crops, Horticulture and Soil, P.O Box 536-0000, Njoro3Kenya Agricultural Livestock and Research Organization- Tigoni, P.O Box 338-0217, Limuru

*Corresponding authors 1*kilonzijack@gmail.com, +254725605844

Abstract Regular application of fungicide including copper based over cropping seasons has raised not only their efficacy in late blight management but also biodiversity and climate change concern. Field trial was to determine the efficacy of Trichoderma asperellum seed treatment concentration on Ridomil® application interval to manage late blight. 21, 14 and 7 days (Manufacturer recommended interval (MRI)) fungicide interval was applied on pre-treated seed with T. asperellum at concentration of 33 % (3 × 1006), 66% (7 × 1006) and 100% (1 × 1007 CFU/mL) the Manufacturer’s Recommended Rate (MRR)). 7 and 14 days spray interval were not significantly different (p=0.05) in terms of yield and late blight severity. 21 days interval was an intermediate between the unsprayed and 14 days interval. Environmental factors contributed to higher disease severity during long rains than short rains. Sprout emergence and survival was reduced by 32% and 21% on tuber and apical cuttings respectively in untreated. T. asperellum at 66%, 100% concentration and Mistress 72® reduced disease severity by 26%, 27% and 26.5% while increasing yield by 30%, 29% and 28% respectively relative to untreated control. Combination of 66% concentration T. asperellum seed treatment with 14 days interval provided better late blight management. The results suggest that seed treatment could delay late blight epidemics resulting to increased fungicide application interval thereby lowering the number fungicide applications.

Effects of cattle manure on growth and yield of tomato (solanum lycopersicum.) Under greenhouse condition in uasin gishu county.Gloria C., P.NM.Njeru and S.K. KimaniMateeny Soy Farmers’ Cooperative society limited, P.o Box 269-30105 Soy

*Corresponding Author:. tetichgloria@gmail.com

AbstractThe tomato is the edible, often red, berry of the plant solanum lycopersicum, commonly known as a tomato plant. The species originated from South America. Though we technically eat the fruit of the tomato plant, the tomato is typically treated as a vegetable in eating and cooking and thus categorized as such .Tomatoes are an important commercial crop for horticulture farmers in Kenya. The market is strong and the crop is relatively easy to grow. It is a favorite for greenhouse farmers. Globally the demand for food is increasing due to increase in population. Degrading soils necessitates novel approaches to soil fertility management. The aim of this research was to investigate the effects of cattle manure and inorganic fertilizer in tomato production under

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greenhouse conditions in Uasin-gishu County, Kenya. The research treatments were organic manure, inorganic fertilizer, combined inorganic and organic fertilizers and a farmers practice. The treatments were arranged at a completely Randomized block design with six replications making a total of twenty four plots. Tomato growth characteristics and yield were measured and the data subjected to analysis of variance (ANOVA).Combination of organic and inorganic fertilizer recorded the highest number of fruits hence highest yield. On the other hand Farmers practice gave the lowest number of fruits thus lowest yield.The study concluded that combination of organic and inorganic supplied the require plant nutrients, improves soil structure and water holding capacity. I therefore recommend to greenhouse farmers to use combination of organic and inorganic fertilizer for maximum tomato production.

Evaluation of Maize Varieties under Two Fertilizer RegimesKamidi M.1, E, Wanjekeche1, M. Koech1, Mutoko1, K. Ndung’u1 J. Barkutwo1, J. Wanyama1, V. Ouma1 A.O. Esilaba3, M. Okoti3, E, Thuranira2, L. Wasilwa3, C. Githunguri2, D. Nyongesa2, J. Miriti2

1 Kenya Agricultural Research Institute (KALRO)-Kitale, P. O. Box 450-30200, Kitale2 KALRO-NARL, P. O. Box 14733-00800, Kabete3 KALRO-Headquarters, P. O. Box 57811-00200, Nairobi

*Corresponding author: kamidimargaret@yahoo.co.uk

AbstractThis study was undertaken during 2016 and 2017 to demonstrate and expose farmers to ten high yielding maize varieties for them to observe performance, adopt them, increase yield hence food security and income. The maize was planted with and without fertilizer. At KALRO Kitale, the differences in grain yield among the varieties were significant (P<0.5), in both years. Varieties H6213 and H629 were among the top three varieties for yield in both years. No significant differences (P>0.5) were observed in grain yield on-farm in Trans Nzoia during both years. Lime had no effect on the yields of maize during 2016. There were significant differences (P<0.05) in biomass production among varieties both on-station and on-farm. A range of 5.76 t/ha was observed on-station between H6218 with the highest biomass and Pioneer the lowest and 7.08 t/ha on-farm between H6210 and the lowest H614D. H6210 had the lowest number of rotten cobs compared to PAN691, Pioneer, and H614D that had the highest.In Nandi county, there were significant differences (P<0.5) in maize yield in both years on station and on-farm in 2016. Hybrids H6213 and H6210 were among the top three varieties for yield overall. There was no significant response to fertilizer in the first year but significant differences (P<0.5) were observed in 2017 at all sites. No significant difference was observed in the number of rotten cobs. In 2017 fertilizer increased biomass production on-farm by 2.53 t/ha in Trans Nzoia and 2.59 t/ha in Nandi. Overall increment on-station was 2.76 t/ha and 1.58 t/ha at KALRO Kitale and Baraton respectively. There were no significant differences in both harvest indices among varieties in all sites. Seed density range among varieties was only 0.0085 g/100 in Trans Nzoia and 0.007 g/100 in Nandi.

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Book of Absstracts

Potassium Fertilizer Recommendation Rate for Economic Rice Production at Mwea Irrigation scheme - Kenya*Gikonyo1, E.W., Kimani1, S.K., Gichangi1 A., Kibunja1, C.N., Esilaba1, A.O., Mbuthia2, L.W. and Kega1, V.M

1Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. Box 14733-00800, Nairobi, Kenya2International Potash Institute (c/o ICL Limited), P. O. Box 29183-00100 Nairobi, Kenya

Abstract Importance of potash fertilization on most crops to enhance crop yields for food security and income generation cannot be disregarded any more. Balanced fertilization with not only Nitrogen (N) and Phosphorus (P) but also Potassium (K) can lead to sustainable crop yields. The current study aimed at developing potassium fertilizer recommendation rate for maximum rice yields. The two most popular rice varieties viz. Basmati 370 and BW 196 were used. They were grown at 5 rates of K2O (kg/ha) viz. 0, 40, 80, 120 and 160 applied as murriate of potash (MOP). The treatments also received balanced fertilization of nitrogen (N) and phosphate (P) at 160 kg/ha and 60 P2O5 kg/ha, respectively. Micronutrients that tested deficient in the soils, such as Zinc were also applied. Experimental design was, split plot design with fertilizer rates as main plots and rice varieties as the sub-plots. Data collection included plant height (PH) and tillers/hill taken during the growing period whilst grain yields, total biomass yields, maximum tillering and final plant height were measured at maturity. Yield components data viz. panicle length, grain length, panicle weight, 1000 grains weight, filled grains and empty grains were also taken (not included in this paper).The trial was conducted in the main growing season (July to December) for three consecutive years (2016 to 2018). High grain and biomass plot yields were harvested, above the general variety yields in the scheme. Generally, the different yield responses were exhibited by the two varieties. BW 196 variety gave higher grain yields than basmati 370 in almost all the sites. On the other hand, Basmati 370 variety gave lower grain yields but higher BW 196 but the opposite was observed in gross margins. Maximum paddy yields and highest gross margins of the two rice varieties were attained at 80 K2O kg/ha in majority of sites. In conclusion, the K fertilizer recommendations should be considered as 80 K2O kg/ha for both basmati 370 and BW 196. Further work should be done in field demonstrations and up-scaling the results to the entire Mwea and other rice growing regions in Kenya.

Integrating inorganic and organic fertilizers in cropping systems for the transformation of maize productivity in Nakuru CountyOoro, P.A1, Mwangi, H.G1., Esilaba, A.O2., Nyongesa, D3., Miriti, J.M3., Okoti, M2., Lusike, W2., Githunguri, C3., Moraa, L.M1., Bor, P.K1., Luvonga, J1., Osoo, J.O1. and Thuranira, E3.1KALRO-Njoro, P.O. Njoro2KALRO Headquarters, P.O. Box 57811- 00200, Nairobi.3KALRO Kabete, P.O. Box 14733, Nairobi

*Corresponding author: Patrick.ooro@kalro.org and paooro@yahoo.com

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AbstractIn spite of huge importance maize for food security and economic wellbeing of Kenya, the productivity and production have not shown significant improvements over the years. This is attributable to a number of factors including declining soil fertility. A study was therefore conducted between 2016 and 2017 in Nakuru County at the Kenya Agricultural and Livestock Research Organization (KALRO), Njoro Centre, Nakuru County to determine the suitability of Integrated Soil Fertility Management (ISFM). Three factors namely: two soil and water conservation strategies, three cropping systems and four ISFM options in a split-split plot structure replicated four times at on-station trials in a complete randomized block design (RCBD) and in a complete block design (CRD) under on-farm conditions. Data were collected on various maize and beans variables including plant stand at germination, plant vigor, and days to 50% flowering, days to 50% maturity, plant stand at harvest, number of pods per plant, number of cobs, and number of seeds per pod, grain yield, and 100-grain weight. Significantly higher maize yields( p<0.05) were obtained due to the application of full rate of inorganic fertilizer than all the fertility management options except in situations where a half rate of inorganic and organic fertilizers was used. The results further showed a significant increase in maize yield when grown either as sole or intercrop was significantly enhanced by the addition of inorganic fertilizer alone compared to farmyard manure applied alone or in combination with inorganic fertilizer under on-station conditions during the year 2017. Significant maize grain yield increase with application of inorganic fertilizer alone or in combination with farmyard manure was an indication that maize would benefit ISFM options. In an intercropping system of maize and beans, the results generally showed maize as a good competitor and this compromised the yield of beans.

Effect of zinc on yield of sorghum and green gram in semi-arid eastern KenyaP. Kathuli1, D. Mutisya1, D. Macharia1, A. Esilaba2, A. Kathuku2, D. Nyongesa, L. Wasilwa2

1KALRO AMRI Katumani. P. O. Box 340. 90100. Machakos.2KALRO Headquarter. P.O. Box 57811. 0200. Nairobi.

*Corresponding author: peterkathuli@yahoo.com

AbstractFarming communities in Kenya lack information on importance of zinc as an important fertilizer ingredient in crop production systems of the country in soils with zinc deficiency. A field study was established to evaluate zinc fertilizer requirement in sorghum and green grams. The test crop was sole sorghum and green gram intercropped systems. Zinc fertilizer rates were 0, 5, 10, 15 and 20 kg/ha zinc. The experimental design was RCBD with a split plot replicated 4 times. Zinc fertilizer was the main plot while cropping systems were in split plots. The experiment was carried out for two seasons. The results showed that, sole sorghum stands appeared to significantly (p < 0.05) respond to higher (> 10kg/ha) zinc levels in first season but in second season there were no significant differences. Both plant biomass and highest yield peaks were scored at zinc levels of greater than (>) 10 kg/ha. Sorghum yield was generally low probably due to rainfall amounts received. Sole sorghum responded significantly to zinc at rates greater than 10kg/ha in one season while there was no significant response to zinc application in second season prompting further research work on zinc response on sorghum and sorghum green gram intercrop in the study site. This further work would be supported by soil analysis for available zinc from the site

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Soil fertility inputs on sorghum performance in semi-arid areas of Embu and Tharaka-Nithi countiesIrene Njagi1, Alfred Micheni1, Peter Kinuthia1, Patrick Gicheru1, Dave Nyongesa3, Anthony Esilaba2, Silas Muriithi1, Elias Thuranira3, Madrine Nthiga1

1Kenya Agricultural and Livestock Research Organization (KALRO-Embu), P.O. box 27-60100, Embu2Kenya Agricultural and Livestock Research Organization (KALRO Headquarters), P.O. box 57811-00200, Nairobi3Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. box 66730-00800, Nairobi

*Corresponding author: irene.njagi@kalro.org

AbstractLow soil fertility levels has been one major factor limiting household food security especially in the sub-Saharan region of Africa. Loss of nutrients through harvested products and leaching has resulted in reduction of yields in croplands. This study therefore seeks to alleviate this through the use of fertilizer and manure and their combinations for increased yields. The main objective was to demonstrate the effects of different fertilizers (organics and inorganics) on crop yields in semi-arid areas of Embu and Tharaka-Nithi Counties.For three seasons (October 2016, April 2017 and October 2017 rainy season), the trials were therefore managed in Mbeere and Tharaka in Embu and Tharaka-Nithi County, respectively. The trials had 8 treatments replicated 3 times. The treatments consisted of tillage systems and soil fertility inputs, arranged in a split-plot in a randomized complete block design and planted with sorghum. The tillage methods were allocated the main plots, while the fertilizer types were allocated to the sub-plots. In the three seasons of testing, there were no significant differences in sorghum yields due to fertilizer, manure or/and their combinations. Application of these inputs significantly increased the crop yield when compared to the no input system, - indicating that fertility inputs application is beneficial for improving crop yields in semi-arid areas. The study recommended for more research on the cost benefit of using various soil fertility inputs with different crops and agro-ecological zones.

Effect of soil fertility inputs on green gram yields in semi-arid areas of Embu and Tharaka-Nithi countiesPeter Waweru1, Alfred Micheni1, Irene Njagi1, Patrick Gicheru1, Elias Thuranira3, Dave Nyongesa3, Anthony Esilaba2 and Silas Muriithi1

1Kenya Agricultural and Livestock Research Organization (KALRO-Embu), P.O. box 27-60100, Embu2Kenya Agricultural and Livestock Research Organization (KALRO Headquarters), P.O. box 57811-00200, Nairobi3Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. box 66730-00800, Nairobi

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*Corresponding author: peter.waweru@kalro.org

AbstractLow soil fertility levels has been one major factor limiting household food security especially in the sub-Saharan region of Africa. Loss of nutrients through harvested products and leaching has resulted in reduction of yields in croplands. This study therefore designed to determine ways of alleviating the soil infertility challenge through the use of fertilizer and manure and their combinations for increased green gram yields in semi-arid zones of Embu and Tharaka-Nithi Counties. For three seasons (October 2016, April 2017 and October 2017 rainy season) the trials were managed with 8 treatments replicated 3 times. The treatments consisted of tillage systems and soil fertility inputs arranged in a split-plot in a randomized complete block design in three replications. The tillage methods were allocated the main plots, while the fertilizers were allocated to the sub-plots. Results indicated that application of fertilizer, manure and their combinations yielded similar yields for all the three seasons under study. The only difference was from the no input treatments, - indicating that application of inorganic fertilizers and manure or/and their combinations improved yields. The study recommended for more research on the cost benefit of using various soil fertility inputs with different crops and agro-ecological zones.

Zinc based fertilizer on greengrams and sorghum yields in semi-arid areas of Embu and Tharaka-Nithi countiesMicheni, A.N.1., Esilaba A.O.2., Njagi I.W.1., Thuranira E.G.3., Kinuthia P.W.1, Gicheru P.T.1, Nyongesa D3. & Muriithi S.N1.

1Kenya Agricultural and Livestock Research Organization (KALRO-Embu), P.O. box 27-60100, Embu2Kenya Agricultural and Livestock Research Organization (KALRO Headquarters), P.O. box 57811-00200, Nairobi3Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. box 66730-00800, Nairobi

*Corresponding author: alfred.micheni@kalro.org

AbstractZinc (Zn) is a critical micronutrient for the growth and reproduction of cereals and pulses. A study for evaluation of different rates of zinc fertilizer on sorghum and green grams grain yields was conducted at Kenya Agricultural and Livestock Research Organization (KALRO Marimanti) in Tharaka-Nithi County and at the Agricultural Technology Development Center (ATDC) in Embu County. A completely randomized design (CRD) with three replicates was used to lay out the experiments. Zinc was applied in the form of zinc sulphate fertilizer where 5 levels of zinc treatments (0, 5, 10, 15, 20kg ha-1) were incorporated into the soil before sowing the seeds. Data collected were on grain yields. Application of zinc fertilizer at 5 and 20kg ha-1) significantly improved the growth and yield parameters of sorghum and green grams. A recommendation was therefore put forward to further test the zinc element in different soils and crop species.

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Diammonium phosphate or NPK-23-23-0 for maize and wheat production in the acidic soils of Uasin Gishu*Gikonyo, E.W.1, Gacheru, E.N.1, MuriukiA.W.1, Kibunja C.N.1, Kamau, D.M.1, Ogolla, H.2, Ouko, O.C.2

1Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. Box 14733-00800, Nairobi, Kenya2Chemagro international Limited, International House, 12th Floor, PO. Box 75914-00200, Nairobi-Kenya.

*Corresponding author: estgikonyo@yahoo.com, est.gikonyo@gmail.com/Esther.Gikonyo@kalro.org, Phone Number: +254705895208

AbstractThe major purpose of the study was to quantify the advantages of Ma’aden DAP compared to other N and P source fertilizers found in the Kenya market. Since Ma’aden DAP has low impurities (heavy metals) and is of high solubility, it is envisaged to become the preferable fertilizer of choice. The specific objectives were to: 1) inventorize the most commonly used phosphate fertilizers 2) establish the efficacy and cost-effectiveness of best practice Ma’aden-DAP fertilizer application for maize and wheat production 3) determine heavy metal uptake from Ma’aden-DAP fertilizer and other commonly used phosphate fertilizers in Kenya using spinach and amaranth, 4)demonstrate that liming reduces soil acidity even when DAP is used continuously and 5) establish that the risk of cadmium transfer to the food chain is higher on acidic soils. Results from the maize and wheat trials indicated response to fertilizers in all sites in Nyeri, Murang’a and Uasin Gishu except Ngodecwa site in Uasin Gishu farm for maize. Maize yields varied from County to County and site to site and the fertilizer treatments. Lowest maize yields were attained were about 0t/ha in the control treatment, in the strongly acidic soils at Simbi in Uasin Gishu County. The highest maize grain yields attained were 7.2t/ha at Kihate site in Nyeri County. In majority of cases Ma’aden and Ma’aden + lime treatments gave the highest yields but not significantly different from the other DAP fertilizer. In Kihate site application of lime + Ma’aden DAP and DAPX+Lime increased maize grain yields by 65.8% and 38.6%, respectively. All other sites in Nyeri and Murang’a did not show significantly different responses to maize grain yields. In Uasin Gishu, lowest maize yields of almost 0 t/ha were attained in the strongly acidic site of Simbi. Application of lime and the DAP fertilizers increased yields by up to 468%. The so called ‘non-acidifying fertilizer’ NPK-17-17-17 gave very low yields in Uasin Gishu compared to the DAPs, even when it was applied at double the rate of DAP. In wheat, a similar trend to that in maize grain yields was observed. Application of the DAPs plus lime increased wheat yields to about 5t/ha, which was 200% compared to the sole DAPs while NPK-17-17-17 resulted in 50% lower wheat yields compared to the DAP fertilizers particularly, in the strongly acid soils. Thus, Ma’aden DAP would be preferred to other DAPs tested in this study.

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SUB THEME 3

Enhancing the Status of Food and Nutrition Security and Incomes through Soil Health and Quality Improvement and Agricultural Water Management

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Changes of soil conditions and maize yield after years of conventional or reduced tillage on a mollic andosolMwangi, H.G., Irene, W.G, Ooro, P.A1. 3Esilaba A. O. , 3Githunguri, C. and 3Lusike, W.

1 Kenya Agricultural Livestock Research Organization, KALRO-Njoro, Private Bag, NjoroEmail : hgachuna2003@yahoo.co.uk, Phone: +254723697936,2Department of Microbiology and Biochemistry University of Nairobi, P.O. Box, 29053, Nairobi, Kenya, 3KALRO Headquarters, P.O. Box 57811- 00200, Nairobi

AbstractSoil tillage affects soil physical, biological and mineral nutrient cycling capacity and hence soil quality in diverse ways. Intensive tillage may break the soil physical structure and influence soil water retention capacity. Soil disturbance may affect soil biological biodiversity that provide essential services for the sustainable functioning of all ecosystems. Tillage may also affect availability of C, N, and S nutrients that are largely mediated through microbial community. The objective of this study was to evaluate changes in some soil properties induced by two different tillage systems and their effect on maize grain yield. Field studies were conducted from 2016 with continuous maize on same site using two tillage systems; conventional tillage CT and reduced tillage RT at KALRO-Njoro on a mollic Andosol. Changes in water stable aggregates %WSA, compaction as measured by changes in bulk density (b d), soil water retention at pF 4.2, total soil organic carbon and hence organic matter (SOM), Microbial biomass (bacteria and fungi), in form of total microbiol biomass-N and microbiol biomass-C and maize yield were obtained after three years in 2018. With exception of bulk density that as found to be higher in CT, results showed that aggregate stability %WSA,soil water retention capacity at pF4.2, SOM, total microbiol biomass-N and microbiol biomass-C were higher in RT as factors that were adversely affected by intense soil disturbance. Maize grain yield was significantly (p<0.05) higher in reduced tillage. Bulk density of the soil was observed to be higher after 3 years of conventional tillage compared to reduced tillage. Reduced tillage increased SOM, structure, water retention, and microbial biomass and maize yields. This study has demonstrated that RT is pivotal in healing the highly weathered soils that have become degraded and soil fertility has declined through decades of continuous disc and plow tillage, lengthy exploitation and nutrient mining leading to low crop yields.

Tillage, residue management and cropping systems affect soil aggregation, organic carbon and microbial biomass in tropical Ferralsols of western KenyaPeter Omondi Bolo1, 2*, Job Kihara1, Monicah Mucheru-Muna2a, Ezekiel Mugendi2b

1International Centre for Tropical Agriculture (CIAT), Nairobi, Kenya2aSchool of Environmental Studies; Department of Environmental Sciences Kenyatta University, Nairobi, Kenya2bSchool of Pure and Applied Sciences; Department of Microbiology Kenyatta University, Nairobi, Kenya

* Corresponding author email: p.bolo@cgiar.org. Contact: 0713285830;

Abstract

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Soil aggregates are important indicators of soil health, nutrient status and ability to resist erosion. This parameter is sensitive to soil disturbances that occasion disintegration of aggregate sizes, loss of organic carbon and physical killing of the soil dwelling macro- and micro-fauna. Numerous agronomic practices have been promoted to enhance sustainable food production, but little concern has been taken on the effects of such practices on soil aggregate stability and microbial biomass and soil organic carbon, yet these are vital indicators of soil health, nutrient availability and structure maintenance. A study was conducted in Western Kenya to assess the effects of tillage, cropping systems and residue management on soil aggregate stability, microbial biomass carbon and soil organic carbon. At both depths assessed (0-5 cm and 5-15 cm), tillage, cropping systems and residue retention significantly (P ≤ 0.05) affected soil aggregate stability. Mean weight diameter (MWD) was significantly higher (P ≤ 0.05) in; Reduced tillage (RT) than conventional tillage (CT) (P ≤ 0.05), maize-soybean intercrop compared to rotation system (P ≤ 0.05), and in residue retention compared to residue removal treatment (P ≤ 0.05). Microbial biomass carbon was not significantly affected by either tillage, reside retention or cropping systems, but was 23% and 29%, respectively higher in reduced tillage and maize-soybean intercropping systems respectively. Soil organic carbon (SOC) was not significantly affected by treatments, but was slightly higher in residue retention (3.57%) and maize-soybean intercropping systems (6.0%). These findings suggest that practicing reduced tillage, combined with residue retention while observing proper cropping systems can markedly reduce the susceptibility of soil to erosion, improve soil organic carbon and increase soil microbial biomass.

Soil health constraints contributing to maize (Zea mays l.) yield gap in Upper Tana watershed of Murang’a County, KenyaErmias Aynekulua, *, Robin Chachaa, Ruth Sitieneib, Felix Kamaub, Klauser Dominikc, Samuel Steinerc, Damaris Mboi a, Keith Shepherda

a World Agroforestry Centre (ICRAF), United Nations Avenue, P.O. Box 30677-00100, Nairobi, Kenyab The Nature Conservancy, 31 El Molo Drive Maji Mazuri Road Lavington, Nairobi -Kenyac Syngenta Foundation for Sustainable Agriculture, Nairobi – Kenya, P.O Box 30393 - 00100*Corresponding author: E-Mail: e.betemariam@cgiar.org; Tel.: +254207224356; fax: +254207224001; ruth.sitienei@tnc.org; Tel: +254725473899; fkamau@tnc.org; Tel: +254786583113

AbstractSmall-scale farming in sub Saharan Africa is central to food security. However, subsistence farming is not yet meeting its role in reducing the current yield gaps and ensuring food security. Current agronomic recommendations are too broad to be useful and remain largely un-validated. Therefore, there is a growing demand for high precision information on soil conditions and agronomic performance to guide investment decisions on use of agro-inputs and other land management interventions. We collected 524 soil samples (0-20 and 20-50 cm depth ranges) to identify soil-health constraints for targeting interventions to improve maize production in Murunga County, Kenya. Our results showed that the soils in the study area were short of both macro (N, P, K) and micro (B, Zn, Mn, Cu) nutrients which – without substantial nutrient input - makes them marginally suitable for maize production. About 75% of the soils have pH values which are suitable for maize production while the remaining 25% are slightly acidic. Future

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management should consider maintaining the current pH level of most soils. DAP (18:46:0) and CAN (26:0:0) were the most widely applied fertilizers as basal and top-dressing applications, respectively. The current fertilizer application does not address the critically low potassium & Micro nutrient levels in the study area. About 78% of the top soils have a soil organic carbon value of less than 2%, indicating a need to apply more organic inputs.

Growth of rainfed maize and soil microbial dynamics under different soil agronomic practicesNyamwange, M.M., Njeru, E.M., Mucheru-Muna, M., Ngetich, F.

1Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, P. O. Box 43844-00100, Nairobi, Kenya2Department of Environmental Sciences, Kenyatta University, P. O. Box 43844-00100, Nairobi, Kenya3University of Embu, Department of Land Use and Water Management, P.O. Box 6-60100, Embu, Kenya

*Corresponding author: Methuselah Mang’erere Nyamwange; cell: +254719376608, Email: nmethu1992@gmail.com

AbstractSoil management practices influence beneficial soil biota, especially arbuscular mycorrhizal fungi (AMF). A five-year field experiment was carried out in Central Kenyan Highlands to determine the effect of tillage, mulching and inorganic fertilizers on the number of AMF propagules in the soil and uptake of nitrogen (N) from the soil. The study involved conventional and minimum tillage systems, mulching using dried maize stovers and inorganic fertilizers (120 kg N/ha). The experiment was set up in randomized complete block design and replicated three times. The number of infective AMF propagules decreased in the following order; V4 stage (p <0.0001), V6 stage (p <0.0001), maize harvest (p =0.0076) and before maize planting (p =0.0061). Minimum tillage + mulch + no NPK fertilizer (ZRO) treatment recorded the highest number of infective AMF propagules with an average of 90 propagules g-1 of soil whereas conventional tillage + mulch + NPK fertilizer (CRF) and conventional tillage + no mulch + NPK fertilizer (CWF) treatments recorded the lowest number of AMF propagules with an average of 1.33 propagules g-1 of soil. Results at juvenile stage showed a strong positive correlation between AMF colonization and shoot N (r =0.928, p <0.0001). These findings demonstrate a strong effect of agronomic management practices on soil AMF propagules which subsequently affected uptake of essential nutrients such as N for growth of maize.

Integrated effects of rhizobium inoculation and phosphorus application on tissue content, rhizobium and phosphorus use efficiency in soybean productionMulambula, S.1*, Gathungu, G.K.1 Ndukhu, H. O1 and Ogolla, F.O.2

1Department of Plant Sciences Chuka., Kenya2Department of Biological Sciences Chuka University, Kenya*1Corresponding author: Email. siomulambula@yahoo.com Tel. 0723860702

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AbstractSoybean (Glycine max) is an important legume crop that is cultivated all over the world as livestock feed, food for human consumption, soil fertility improvement and industrial products such as candles and paints. However, Nitrogen (N) and phosphorus (P) nutrient have been attributed to the decline in soybean yields. Furthermore, scanty information is documented on P-efficient soybean genotypes, which are a sustainable P management strategy for enhancing symbiotic efficiency (SEF) and phosphorus use efficiency (PUE). As a solution, field experiment was conducted at Chuka University farm to evaluate the integration effect of rhizobium inoculation (R) and P on tissue nutrient content, SEF and PUE in soybean production in Meru South Sub County. Two cultivations (Trial I and II) were done in 2018. Treatments included; three rates of R (0, 100 and 200 g ha-1), three rates of P (0, 20 and 30 kg- ha-1), either applied alone or integrated and soybean genotypes (SB19 and SB24). Both Trials were laid out in a randomized complete block design in split-split plot arrangement with each treatment replicated thrice. Genotypes were assigned main plot, R subplots and P in sub-subplots. Data collected was subjected to analysis of variance using the Scientific Analysis System SAS and significantly different means separated using Tukeys test at (p≤0.05). The results showed significant difference in N and P tissue content, SEF and PUE for SB19 and SB24 genotypes in both Trials at (p≤0.05). The highest N tissue content of between 1.73% and 9.10% was observed when integration of R and P were applied at the rate of 200 g and 30 kg for SB19 and SB24 in both Trials. While R and P at the rate of 200 g and 30 kg per ha showed the highest P content of between 849.6 ppm and 955.0 ppm in both Trials. The highest SEF recorded was 207% and 261%, and 201% and 227% in Trials I and II, respectively. The PUE was highest when R and P was applied at the rate of 200 g and 30 kg per ha for SB19 and SB24 soybean in both Trials. Integration of R and P at the rate of 200 g and 30 kg ha-1 and adoption of either SB19 or SB24 showed a potential in enhancing soybean cultivation.

Emissions intensity and carbon stocks of a tropical Ultisol after amendment with Tithonia green manure, urea and biocharFungo, B.a,b,c,, Lehmann, J.d, Kalbitz, K.b,e, enywa, M.f, Thionģo, M.c, Neufeldt, N.c

aNational Agricultural Research Organization (NARO), P.O. Box 1752, Kampala, UgandabInstitute for Biodiversity and Ecosystem Dynamics (IBED), Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The NetherlandscCGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), World Agroforestry Center (ICRAF), P.O. Box 30667, UN, Avenue-Gigiri, Nairobi, Kenyad Soil and Crop Sciences, Cornell University, Bradfield Hall, Ithaca, NY 14853, USA

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e Soil Resources and Land Use, Institute of Soil Science and Site Ecology, Dresden University of Technology, Pienner Strasse 19, 01737 Tharandt, Germanyf Collage of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062, Kampala, Uganda

AbstractBiochar has been shown to reduce soil emissions of CO2, CH4 and N2O in short-term incubation and greenhouse experiments. Such controlled experiments failed to represent variable field conditions, and rarely included crop growth feedback. The objective of this study was to assess the effect of biochar, in comparison to green manure and mineral nitrogen, on greenhouse gas Emissions Intensity (EI=emissions in CO2 equivalents per ton of grain yield) in a low-fertility tropical Ultisol. Using a field trial in western Kenya, biochar (0 and 2.5 t ha−1; made from Eucalyptus wood) was integrated with urea (0 and 120 kg N ha−1) and green manure (Tithonia diversifolia; 0, 2.5 and 5 t ha−1) in a factorial design for four consecutive seasons from October 2012 to August 2014. Compared to the control, biochar increased soil CO2 emissions (9–33%), reduced soil CH4 uptake (7–59%) and reduced soil N2O emissions (1–42%) in each season, with no seasonal differences. N2O emissions increased following amendment with T. diversifolia (6%) and urea (13%) compared to the control. Generally, N2O emissions decreased where only biochar was applied. The greatest decrease in N2O (42%) occurred where all three amendments were applied compared to when they were added separately. EI in response to any of the amendments was lower than the control, ranging from 9 to 65% (33.0 ± 3.2 =mean ± SE). The amendments increased SOC stocks by 0.1–1.2 t ha−1 year−1 (mean ± SE of 0.8 ± 0.09 t ha−1 year−1). The results suggest decreased net EI with biochar in low fertility soils mainly through greater net primary productivity (89% of the decrease).

Effect of Different Soil Enhancements on Maize Grain Yield and its Parameters in Central Highland of Kenya for Improved ProductivityKenya Agricultural & Livestock Research OrganizationCentre- Kalro Embu P. O. Box 27Embu, Kenya Fax: 068 30064 *Corresponding Authors: Catherine.muriithi@kalro.orgmuriithicatherine16@gmail.com

Abstract Low maize productivity in Central Kenya highlands is contributed by various factors such as to low soil fertility, poor agronomic practices, minimum use of agricultural inputs, pest and diseases and use recycled seed. Soil fertility decline has the greatest contribution to this low productivity. The objective of the study was to evaluate nutrient management technologies on acidic soils using organic and inorganic commercial fertilizers to improve soil fertility and to monitor soil pH status following application of these enhancements. The study was conducted in six counties namely Nyeri, Embu, Kirinyaga Meru, Murang’a and Tharaka Nithi for both organic and inorganic fertilizers combined with water harvesting technologies through furrow and tied ridges. The test crop were two maize hybrids (H517 and Duma 43). The plots were laid in Randomized complete Block Design (RCBD) and counties being replicates. The plot size was 10m x 10m. At harvest, the outer rows on either side of the plot and the last plant in each row were removed and data collected from the middle rows. The treatments included

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NPK 23.23.0 at 250kg ha-1 and cattle manure at 5.0t ha-1, Mavuno blend fertilizer applied at 250kgha-1 and cattle manure alone at 5.0 t ha-1 and top dressed with CAN in all the plots, The three treatments were applied in furrow and tied ridges while the same treatments were applied on the flat bed and top dressed with CAN at 60kg/ha at knee height. Data was subjected to analysis of variance (ANOVA) and means separation using LSD carried out. The results showed significance difference (P<_=0.0017) in plant height. A combination of furrow and ridges combined with Mavuno blend fertilizer + Manure produced the tallest (232.80 cm), highest weight of stovers (10.05 T/Ha) and highest grain weight of 6.67 T/ha while Flat Bed Manure alone recorded the lowest grain weight (4.16 T/Ha). It also showed the lowest plant height as well as stover weight.

SUB THEME 4:

Crop-Livestock Integration Options for Sustainable Intensification and Diversification of Farming Systems

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Properties of Spent Mushroom Substrate and its Potential uses Particularly in Crop and Animal Production Systems: A review.Gateri M. W1., Muriuki A. W. and E. Irambu

1Food Crops Research Centre- KALRO-Kabete, P.O Box 14733 – 00800, Nairobi.

Corresponding author: marygmakanga@gmail.com

AbstractMushroom cultivation is taking root in Kenya, promising to generate a large amount of ‘Spent Mushroom Substrate’ (SMS). The management of this organic waste is a major environmental concern especially in the large scale farms where it is left to decompose in piles. However, scope exists on how to recycle this waste in crop and animal production systems which provides a friendlier and economically viable disposal system. Questions arise as to whether farmers in the larger community, scientist as well as entrepreneurs are aware of the existence of this valuable organic waste. This review gives available scientific literature and practical applications of SMS with a view to provide a spectrum of its characteristics and potential use in crop and animal production systems. Scientific journals, technical bulletins, books and papers in conference proceedings were reviewed. It was found that SMS is an organic waste containing both macro and micro nutrients and without the presence or with undetectable levels of heavy metals. It exhibits many other characteristics typical of organic waste including low bulk density, favourable pH, high cation exchange capacity (CEC), low conductivity and optimal C: N ratio with an added advantage of absence of weed seeds and pathogens. Its potential uses include bioremediation, plant fertilizer, animal feeding, pest and disease management, enzyme production, alternative energy and reuse as substrate in mushroom production. Soil application for crop production and animal feeding are promising strategies for recycling the waste. It is concluded that SMS is a valuable resource with good properties and multiple uses.

Crop – livestock integration systems in mountain areas of Northern KenyaDuba Golicha1 and Hassan Charfi2

1Kenya Agricultural and Livestock Research Organization, Marsabit Research CentreP.O. Box 147 – 60500, Marsabit, Kenya2Ministry of Agriculture, County Government of Marsabit

*Corresponding author: golichdub@yahoo.com

AbstractThe mountain areas of northern Kenya is inhabited by agro-pastoralists. Small-scale crop production and livestock keeping is the main sources of livelihoods in the arable mountain areas of northern Kenya. Using structured questionnaires, this study clarified whether there is interdependencies among the crop and livestock components of the farmers in arable northern Kenya. The area of interactions for crop-livestock systems of northern Kenya include: farm power, use of crop residues, manure for field’s fertilization and cash-flows between crop and livestock component. In arable mountain areas of northern Kenya, animal power is mainly used for farm operations like ploughing, and also donkeys are used watering livestock. Nevertheless,

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93% of interviewed farmers use people-power while 40% uses animal-power. Furthermore, during the long rain season, the time of planting is in the month of March for farmers with oxen (animal power) and in the Month of April for the farmers without oxen. Additionally, 71% of interviewed farmers use crop-residues for feeding livestock with negligible amount of crop-residues availed for field’s fertilization. The study also revealed inefficiency in the utilization of manure. In fact, only 43.4% of interviewed farmers use the manures for fertilization, while others throws the manure away. In a nutshell, the crop-livestock systems of arable northern Kenya, lacks the beneficial interconnectedness between the crop and livestock components. The minimal utilization of manure and out-flow of crop-residues into livestock component can result into nutrients imbalance. In-depth research into nutrient flows and capacity building on sustainable crop-livestock integration is necessary for farmers in arable mountain areas of northern Kenya.

Potential of intercropping for increased income, food and nutrition security in Kenyan Arid and Semi-Arid Areas (ASALs)A. N. Kathuku-Gitonga1*, A.O. Esilaba2, N. Mangale1 L. Wasilwa2, M. Okoti2, D. Nyongesa1, P.T. Kamoni1, B. K. Waruru1, E.M. Muya1, E. Thuranira1, D. Mutisya3, D. R. Macharia3

1Kenya Agricultural and Livestock Research Organization, Kabete, FCRI, P. O. Box 14733 – 00800, Nairobi, Kenya2Kenya Agricultural and Livestock Research Organization, Headquarters P. O. Box 57811 – 00200, Nairobi, Kenya 3Kenya Agricultural and Livestock Research Organization, Katumani, AMRI, P.O.BOX 340 – 90100, Machakos, Kenya

* Corresponding author:andanus@gmail.com; angela.ndanu@kalro.org

Abstract Food and nutrition security and lowering the risk of climate change have increasingly become national critical challenges, especially in fragile ecological zones. Sustainable food production thus has to take the centre stage to meet the above challenges. Intercropping legumes with cereals crops could play a key role in this context by delivering multiple services in line with sustainability principles. The first study was a desk study which collated, collected and harmonized previous research on intercropping over a long time. These were published data from previous research work done for more than 50 years in Kenya. The second was an on-station study where sorghum was intercropped with green grams under different fertilizer regimes. The harmonization results showed that beans performed well under mono-cropping. However, in an intercropping set-up, when bean were inoculated with rhizobium, both maize and beans had high yields and highest benefit cost ratio (BCR). Cowpeas when rotated with cereals (maize or millet) had the highest yield and benefit cost ratio. Pigeon peas performed well particularly when organic fertilizers were applied and improved maize yields. The on-station results showed that sorghum/green gram intercropping was beneficial for food security. Sole cropping performed better for both sorghum and green grams.

Appropriate cropping pattern for improved land productivity on terraced Andosols in Suswa, Narok County, Kenya

*Alice Rutoa, Charles Gachenea, Patrick Gicherub, David Mburuc and Zeinabu Khalifd

aUniversity of Nairobi, Department of Land Resources Management and Agricultural Technology, Faculty of Agriculture, P. O. Box 29053-00625, Nairobi, gachenecharles@gmail.combKenya Agriculture and Livestock Research Organization, Embu P.O. Box 27-60100, Embu, ptgicheru@yahoo.comcJomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00100, Nairobi. dmburu.mburu13@gmail.comdUnited Nations Development Program P.O. Box 30218-00100 UN Complex Gigiri, Nairobi. zeinabu.khalif@undp.org

*Corresponding author: arutoc@gmail.com

Abstract A field experiment was carried out in Suswa, Narok County in the crops’ growing season of 2013-2015 to determine a suitable cropping pattern to optimally utilize moisture in terraced fields. A randomized complete block design was used with maize and beans as test crops. The study examined, under different cropping patterns (CP) soil moisture, soil nutrients and crop yields in terraced and on non-terraced farmers’ fields as control (CP4). The results showed significant differences (p≤0.05) in moisture and nutrients availability with bottom terrace position recording on average higher (15%) moisture content compared to 13% in upper position. The bottom recorded 16 and 21% higher soil carbon and 33 and 48% higher N than the mid and upper positions, respectively. The bottom had the highest soil P (24.88) followed by mid (18.36) and top slope (14.85) ppm. K however was not affected by slope position. The yields were significantly (P<0.05) higher according to terrace slope position with values ranging from 7.2 t ha-1 to 3.0 t ha-1 for maize and 1374 kg ha-1 to 306 kg ha-1 for beans in lower and upper slope respectively. Significant differences (P<0.05) were also observed in cropping patterns with CP2 on average recording the highest (803 kg ha-1) bean yields and CP4 (control) the lowest (576 kg ha-1) in season I. The study found CP2 (Maize/Bean in upper and lower slope position and sole bean in the middle) most favourable for the study area and concluded that terracing and appropriate cropping pattern improved land productivity

Effect of land configuration and cow dung on maize performance in Minna, Southern Guinea Savanna zone of Nigeria1Eze, P.C., 2Onyekwere, I. N., 3Azuatalam, C. E., 1Adava, A. O. and 1Ayankeye, O. E..

1Department of Soil Science and Land Management, Federal University of Technology, Minna, Niger State. 2National Root Crops Research Institute, Umudike, Umuahia, Abia State.3Department of Soil Science and Land Management, Federal University of Agriculture, Abeokuta, Ogun State.

*Corresponding author:andanus@gmail.com; angela.ndanu@kalro.orgCorresponding Author: ezepc66@gmail.com; ezepemec66@yahoo.com; peter.eze@futminna.

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edu.ng

Abstract

Field trials were carried out during the 2014 and 2015 growing season to evaluate the performance of maize as affected by different land configurations and rates of application of cow dung in Minna, Nigerian southern guinea savanna zone . The land configuration (ridge, flat and mound) and cow dung application rate (0, 5 and 10 tons ha-1) treatments were arranged in a randomized complete block design and replicated four times. Agronomic practices carried out included land preparation, planting, thinning, weed control, fertilization, harvesting and processing of maize cobs. Plant height at seedling emergence, vegetative growth, tasseling and maturity stages, grain and stover yields, cob length and cob weight after crop harvest were determined. In this study, it was found that land configuration had significant (P ≤ 0.05) influence on cob length and plant height at the seedling establishment and tasseling growth stages. Planting on the flat and on ridges, and application of 10 tons ha-1 of cow dung produced the tallest (P ≤ 0.05) maize plants. Land configuration did not significantly affect grain yield, stover yield, cob length and cob weight, while 10 tons ha-1 cow dung application rate resulted in the highest grain yield, cob length and cob weight. Application of cow dung as manure at 10 tons ha-1 has the potential for improving maize performance for sustainable food security.

Evaluation of the Effects of Goat Manure-Based Vermicompost on Soil Chemical Properties under Garlic Production in Eastern KenyaGichaba, V.M1*, Ndukhu, H.O1, Muraya, M1, Odilla, G.A2

1Department of Plant Sciences, Chuka University, P.O. Box 109-60400, Chuka-Kenya2Department of Agricultural Education, Agricultural Economics and Agribusiness Management, Chuka University, P.O. Box 109-60400, Chuka-Kenya

AbstractMajority of farmers in Eastern region of Kenya mainly apply chemical fertilizers to boost crop yields. Continuous use of chemical fertilizers causes several adverse effects such as P-fixation, volatilization of essential nutrients and leaching that affect safety of groundwater and agricultural environment. Hence, the effects of goat manure-based vermicompost on soil chemical properties under garlic were evaluated in Chuka University farm, Meru South sub-county and KALRO Embu horticultural field, Manyatta sub-county from 2018 to 2019. The experiment was laid out in a randomized complete block design and replicated thrice. The treatments were; goat manure-based vermicompost applied at five levels (0, 5, 10, 20 and 30 t ha-1), NPK 17-17-17 at 200 kg ha-1 and goat manure (30 t ha-1). Soil sampling and analysis were done before planting on the entire experimental sites and after harvesting of garlic on each experimental plot. The results showed that application of goat manure-based vermicompost had statistically significant difference (p ≤ 0.05) on soil chemical properties. Application of 30 t ha-1 goat manure-based vermicompost showed significantly (p ≤ 0.05) higher soil pH (8.00), total N (0.606%), available P (21.933 ppm) and exchangeable K (0.863 Cmol Kg-

1) than control treatment that had pH (6.59), total N (0.043%), available P (4.67 ppm) and exchangeable K (0.456 Cmol Kg-1) at Chuka. A similar trend was observed in Embu where vermicompost gave significantly higher soil pH (7.91), total N (0.563%), available P (21.053 ppm) and exchangeable K (0.71 Cmol Kg-1) compared to control which had pH (6.54), total

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N (0.03%), available P (4.6 ppm) and exchangeable K (0.34 Cmol Kg-1). The results of this experiment revealed that addition of goat manure-based vermicompost enhanced soil chemical properties leading to improved garlic productivity.

Tillage practices on crop productivity in semi-arid areas of Embu and Tharaka-Nithi countiesNjagi I1., Micheni A1., Kinuthia P1., Gicheru P1., Nyongesa D3., Esilaba A2., Thuranira E3., Muriithi S1 and Nthiga M1.

1Kenya Agricultural and Livestock Research Organization (KALRO-Embu), P.O. box 27-60100, Embu2Kenya Agricultural and Livestock Research Organization (KALRO Headquarters), P.O. box 57811-00200, Nairobi3Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. box 66730-00800, Nairobi

*Corresponding author: irene.njagi@kalro.org

AbstractGlobal food production is currently a major challenge due to the effect of climate change. It is therefore imperative that farming be done using practices that are geared towards mitigating the negative impacts of climate change. The most important management practice imposed on soils and greatly affects crop production systems is tillage. A study was therefore conducted in semi-arid areas of Embu and Tharaka-Nithi Counties of Eastern Kenya to evaluate the effects of tillage practices on cereals and legume yields. The study was conducted during three seasons; October 2016, April 2017 and October 2017. Three tillage treatments; conventional, zero and zai pits tillage methods were tested. The experiments were laid out in a split-split-plot design with three replications. The highest grain yields were attained in Tharaka-Nithi County for the three crops; green grams, millet and sorghum where average yields of 1.82, 1.97 and 2.74 t ha-1 were attained, respectively in October 2017 season. In Embu County, average yields of 1.13, 1.61 and 2.43 t ha-1 were attained for green grams, millet and sorghum respectively for the same season. Higher grain yields were observed for the crops grown in zai pits as opposed to the other tillage systems tested alongside. The study recommended zai pitting as the most effective tillage method in the semi-arid regions.

Soil fertility inputs on sorghum performance in semi-arid areas of Embu and Tharaka-Nithi countiesIrene Njagi1, Alfred Micheni1, Peter Kinuthia1, Patrick Gicheru1, Dave Nyongesa3, Anthony Esilaba2, Silas Muriithi1, Elias Thuranira3, Madrine Nthiga1

1Kenya Agricultural and Livestock Research Organization (KALRO-Embu), P.O. box 27-60100, Embu2Kenya Agricultural and Livestock Research Organization (KALRO Headquarters), P.O. box 57811-00200, Nairobi3Kenya Agricultural and Livestock Research Organization (KALRO-Kabete), P.O. box 66730-

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00800, Nairobi

*Corresponding author: irene.njagi@kalro.org

AbstractLow soil fertility levels has been one major factor limiting household food security especially in the sub-Saharan region of Africa. Loss of nutrients through harvested products and leaching has resulted in reduction of yields in croplands. This study therefore seeks to alleviate this through the use of fertilizer and manure and their combinations for increased yields. The main objective was to demonstrate the effects of different fertilizers (organics and inorganics) on crop yields in semi-arid areas of Embu and Tharaka-Nithi Counties.For three seasons (October 2016, April 2017 and October 2017 rainy season), the trials were therefore managed in Mbeere and Tharaka in Embu and Tharaka-Nithi County, respectively. The trials had 8 treatments replicated 3 times. The treatments consisted of tillage systems and soil fertility inputs, arranged in a split-plot in a randomized complete block design and planted with sorghum. The tillage methods were allocated the main plots, while the fertilizer types were allocated to the sub-plots. In the three seasons of testing, there were no significant differences in sorghum yields due to fertilizer, manure or/and their combinations. Application of these inputs significantly increased the crop yield when compared to the no input system, - indicating that fertility inputs application is beneficial for improving crop yields in semi-arid areas. The study recommended for more research on the cost benefit of using various soil fertility inputs with different crops and agro-ecological zones.

Effect of maize-cowpea cropping patterns on soil moisture conservation in Meru and Tharaka Nithi countiesKirimi, I. Mwenda1, Munyiri, S. W2, Ndukhu H. O3

1Department of Plant Sciences, Chuka University, P. O. Box 109-60400, Chuka Kenya

*Corresponding author; Kirimi Ian Mwenda: Email: ianmwenda89@gmail.com

AbstractGiven the frequent drought pressure caused by the unpredictable and limited precipitation concurrent with global climate change, highly efficient cultivation technologies have been increasingly recognized by various levels of scientific communities. Maize (Zea mays L.) based intercropping systems are widely practiced in Kenya, but only a few studies have focused on cowpea (Vigna unguiculata L.) as the companion intercrop. This two site study was conducted during the 2018 long rains of March-April at the Kenya Agricultural and Livestock Research Organization (KALRO) Igoji research station and Magutuni in Meru and Tharaka-Nithi Counties Respectively. The objective of the study was to assess the effect of incorporating cowpea into the maize production pattern on crop cover and soil moisture content (SMC). Randomized complete block design was used in the experiment with three replications in 3 x 4 m plots. The treatments comprised of pure maize stand (T1), maize intercropped with inoculated cowpea (T2), maize intercropped with non-inoculated cowpea (T3) and pure non-inoculated cowpea (T4). A generalized linear model (GLM) was used to determine the effects of cropping patterns on ground cover, leaf area index and soil moisture content, using Genstat

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19th edition. Means were separated using Fischer’s protected least significant difference (LSD) test, with differences considered significant at P ≤ 0.05. Significantly higher (82%) crop cover was exhibited at kernel development stage in T2 compared to 78, 64 and 53% in T3, T4 and T1 respectively. Similarly, the highest SMC was recorded at kernel development stage: 210.3, 209.3, 200.2 and 196.4 mm in T2, T3, T4 and T1 respectively. Relative to (T1 and T4), (T2) recorded the peak LAI of 3.75 at 70 DAP at Igoji and 3.16 at 63 DAP in Magutuni. The study showed that cowpea is a promising legume crop that could be integrated into maize cropping patterns to improve moisture conservation.

Maize inoculation with Arbuscular Mycorrhizal Fungi as a striga control methodD. Samanya1, J.B. Tumuhairwe1and S.Dahlin2

1College of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062 Kampala, Uganda2Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala*Corresponding author: dsamanya@yahoo.com

Abstract

Striga hermonthica is a semi-endo - parasite that causes enormous and sometimes complete maize yield losses if left unbridled. Its infestation is high in areas of low rainfall and soil fertility. Arbuscular Mycorrhizal Fungi (AMF) inoculation on sorghum both in the screen house and field reduces striga attachment and emergence in soils with high striga seed bank due to the reduction in strigolactone release by maize plants upon mycorrhizal colonization, release of cyclohexene during decomposition of AMF and increase in nutrients in the rhizosphere due to enhanced nutrient solubilsation and mobilization by the AMF hyphae. However, the effect AMF inoculation and the integrative effect of AMF inoculation and P application on maize on striga hermontheca emergence in the field has not yet been explored. The aim of the experiment therefore was to determine the effect of Arbuscular Mycorrhizal Fungi (AMF) inoculation and the integrative effect of AMF inoculation and P application on maize on Striga hermontheca emergence. A field experiment was conducted in Namutumba District, eastern Uganda with Arenosols as the dominant soil type and low annual precipitation. A Randomized Complete Block Design (RCBD) with split plot arrangement was used and replicated three times. The main plot was cropping system, i.e., maize monocrop, subplots were AMF strains, sub-sub plots were fertilizer levels (P: 30 kg/ha), and control was without any fertiliser and/or AMF applied. Inoculation of maize with AMF Inoculation of maize with AMF significantly reduced Striga hermontheca emergence in the field (0.26/m2 plot). However, integrating AMF inoculation (14g/hill) with P (30kg/ha) application on maize seeds did not have any significant effects on striga emergence. In addition, inoculation of maize with AMF did not significantly increase maize yield. Therefore, inoculating AMF on maize can be used as a striga control method.

Epidemiology, host range and molecular characterization as a control tool for groundnut rosette assistor virus in western KenyaMabele, A. S. *1, Mukoye, B. 2

, Ndong’a, M. F. O. 1, Were, H. K. 1 and Torrance, L. 3

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1Department of Biological Sciences, School of Natural Sciences (SONAS), Masinde Muliro University of Science and Technology (MMUST), Kakamega, Kenya2Department of Biosafety and Phytosanitary, Kenya Plant Health Inspectorate Service (KEPHIS), Nairobi, Kenya3Cell and Molecular Biology Sciences, The James Hutton Institute (JHI), Invergowrie Dundee DD2 5DA Scotland, United Kingdom (UK)

*Corresponding author: mabeleanthony@gmail.com

AbstractGroundnut (Arachis hypogaea L.) is an important legume in western Kenya, but yields are low and declining. Groundnut rosette disease (GRD) is the main disease causing up to 100% yield loss. Rosette is transmitted by Aphis craccivora Koch and caused by two synergistic viruses, groundnut rosette assistor luteovirus (GRAV) and groundnut rosette umbravirus (GRV) associated with a sat-RNA. Inadequate current information was available on the epidemiology, host range and molecular diagnostics of GRAV in western Kenya. This is a limiting factor on proper management of GRD. This study determined the epidemiology and host range of indicator plants of GRD. A survey of GRD was conducted in Bungoma and Kakamega Counties during the short rains and long rains of 2016-2017. Symptomatic leafy samples were collected in falcon tubes containing RNAlater solution, and preserved for laboratory analysis. Data on incidence and severity was recorded. Screening for resistance to GRAV was done on five popular legume varieties and one solanaceous golden berry. The data collected on incidence and severity was subjected to analysis of variance (ANOVA) and pairwise comparison of means done using Least Significance Difference (LSD) at P ≤ 0.05. A total of 144 farms were surveyed. Rosette incidence was significantly higher in Bungoma (66.51%) than Kakamega (60.52%). Short rains had higher incidence than the long rains season. All tested plants developed typical GRD symptoms and tested positive for GRAV with RT-PCR. The fact that GRD occurs wherever groundnuts are grown in western Kenya, is of great concern and may be the reason for the observed low yields. Leguminosae and Solanaceae crops should not be intercropped with groundnuts to eliminate alternative hosts of GRD pathogens. Incorporation of GRD resistant genes in the local cultivars may be the only practical solution.

Effect of DAP, Mixture of Goat and Poultry Manure on Growth and Yields of Green Grams (Vigna Radiata L.) in Embu County, Kenya.Nyapola Andulu Carolyne1, Johnson Kwach2, Jayne Njeri Mugwe3,

1KALRO-USAID Intern Feed the Future Program, Tom Mboya University College,P.O Box 199-40300, Homa Bay.2Department of Biological and Physical Sciences,Tom Mboya University College, P.O Box 199-40300, Homabay.3Department of Agricultural Resource Management, Kenyatta University, P.O43844-00100, Nairobi, Kenya.

*Corresponding author: caroshiner@gmail.comAbstractGreen grams have high demand of phosphorous as a macro nutrient element. This can be

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provided with organic manure or fertilizer. The objective of the experiment was to evaluate the effect of DAP fertilizer, goat and poultry manure on plant hieght, number of trifoliate leaves, pod number, pod weight and biomass of green grams. The experiment was carried out at University of Embu demostration farm on February, 2018 in a random complete block design (RCBD). The experiment involved four treatment; DAP fertilizer at 50kg/ha, mixture of goat and poultry manure at 10tonnes/ha, DAP fertilizer at 25kg/ha with goat poultry manure at 5tonnes/ha and control (no input). The treatments were replicated thrice and data collected at 6th and 8th week using; tape measure, 30cm ruler and weighing balance. The data collected was entered in excel and then subjected to stastical analysisi software (SAS) for analysis .The means from analysis were separated using L.S.D to evaluate significant different at probability of 5% in ANOVA using student f-distribution.The result showed significant difference on plant hieght and biomass at 8th week, there was no significant difference on plant height at 6th week, number trifoliate leaves, pod number, pod weight The use of mixture of DAP fetilizer, goat and poultry manure gave the highest biomass weight.The poultry goat manure gave the highest plant height.

Evaluation of Traxos One 67.5 EC on Weed Control in Wheat (Triticum aestivum L) in Rift Valley Kenya.Mbanda G.O.1 Amadi D.O.K1., Alomba E.O1., Kipkemoi P.L1., Mukisira C.M2.

1Crop Protection. The Kenya Agricultural and Livestock Research Organisation (Food Crops Research Institute- NJORO)2 Socio-Economics. (KALRO) Food Crops Research Institute- NJORO.

*Corresponding author: mbandago@yahoo.com George.mbanda@kalro.org

AbstractWeeds are the most ubiquitous class of crop pests. While they seldom cause massive crop failures over vast areas they are an ever present nuisance that reduces crop quantity and quality while increasing production costs and human drudgery. If left uncontrolled, the weed populations are capable of reducing crop yields by more than 80%.An experiment was conducted in Njoro (KALRO Field 12 at an elevation of 2160, rainfall of between 931 mm- 1200mm /yr Agro Eco zone LH3 with humic soils called Molic andosols of recent volcanic activity) (Joetdzold et al 1982) site during the long rains of 2014 to evaluate the efficacy of Traxos One 67.5 EC a.i (Pinoxaden 30g/l +Clodinafop propergyl 30g/l + Florasulam 7.5g/l) for control of annual grass weeds and broad leaf weeds in wheat (Triticum aestivum L. c.v. Yombi). Traxos One 67.5 EC was applied at 0.75L ha-1, 1.00L ha-1 and 1.25Lha-

1. Three products were used as the local standard check, namely Puma Super® EC applied at (0.75 L ha-1), Topic® (1.00 L ha-1) and Traxos® 045 EC applied at (1.00 L ha-1). The experimental design was randomized complete block (RCBD) with three replicates. All variables i.e. crop emergence, crop density, crop height, and thousand kernel weight (TKW) and wheat grain yield were exposed to analysis of variance at 95% confidence level and the means separated by LSD at p (≤0.05).The safety of the herbicide treatments on the wheat cultivar planted at the site was also assessed. The results indicated that Traxos One 67.5 EC was effective for control of the annual grass weeds and broad leaf weeds at the rates of 1.0 L ha-1 and 1.25 Lha-1. It was noted that Traxos One 67.5 EC applied at the rate of 0.75 Lha-1 poorly controlled the target

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weeds. There was no visible crop reaction symptoms to the herbicide test rates applied. This meant that Traxos 67.5 EC was effective in the control of both annual grass weeds and broad leaf weeds in wheat.

Performance of maize hybrids under contrasting crop management Strategies in Nakuru CountyOoro, P.A.1, Mwangi, H.G.3, Esilaba, A.O.2, Nyongesa, D.3, Miriti, J.M.3., Okoti, M.2, Lusike, W.A.2, 2Githunguri, C. 3, Thuranira, E.G. 3, Moraa, L.M. 1, Luvonga, J.1., Osoo, J.O. 1 and Bor, P.K.1

1KALRO-Njoro, P.O. Njoro2KALRO Headquarters, P.O. Box 57811- 00200, Nairobi.3KALRO Kabete, P.O. Box 14733, Nairobi

*Corresponding author: Patrick.ooro@kalro.org and paooro@yahoo.com

AbstractMaize (Zea Mays L.,) is the most important staple food crop in Kenya and its variety development has been considered to be the most successful in the Sub-Saharan Africa (SSA). In spite of this, the yields have remained below the general potential. A study was therefore conducted between 2016 and 2017 at KALRO-Njoro Centre and at the farmers’ fields in four wards in Njoro and Molo Sub-Counties. In Njoro Sub-counties on-farm trials were conducted in Kihingo ward whereas in Molo Sub-county, two sites were established in Turi and Elburgon wards. Ten different maize (Z. Mays L.) varieties from four different seed companies including Kenya Seed (H520, H614D, H6210, H6213, H6218 and H625), KARO Seed (KH500 – 31A), Pannar Seed (PAN691) and Pioneer seed company (PHB 30G19 and PN|HB3253) were tested under optimum (with recommended rate of fertilizer) and low input (zero fertilizer) management. The trial was laid out in a randomized complete block design (RCBD) in a split-plot arrangement with four replications at KALRO Njoro site while one replicate of the on-station trial was established as baby trial in a farmer’s field (on-farm). Maize variety was assigned as the main plot while the fertilizer rates management formed the sub-plot. At KALRO Njoro site, the greatest yield fain of 47.4% was achieved with an application of fertilizer and specific maize varieties, PHB3253 increased its yield by about 98% when grown under fertilizer in 2017 and this was followed immediately by H520 with a yield gain of 93% and the least yield gain in that year was Pan691 with as little as 2% gain. Notably in the on-farm sites a variety like KH500 -41A in 2017 had risen in yield by about 55% under fertilizer application and this was followed by H614D which had a yield gain about 37%. Stable varieties are not affected by changes in environment and are therefore climate smart.

Effectiveness of push-pull techniques on choice of companion plants in management of fall armyworm on cereal crops in eastern KenyaD. Mutisya1, J. Wambua1, E. Njiru1, J. Kavoi1, D. Macharia1, A. Esilaba2, D. Nyogesa2

1Agricultural Mechanization Research Institute-Katumani. P. O. Box 340.9010 Machakos 2KALRO HQ/ P.O. Box 57811. 00200. Nairobi.Abstract

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The presence of fall armyworm (FAW), Spodoptera fruigiperda in maize and sorghum production systems in Kenya and the larger African continent continues to cause panic among farmers due to possible crop yield loss. Studies on repellence properties of various crop types as well as trap crops are being advocated for in Kenya Cereal Enhancement work under the Climate Resilient Agricultural Livelihood window (KCEP CRAL); what has come to be known as push-pull technologies to manage FAW damage on major cereals like sorghum and maize. Brachiaria spp and Panicum maximum grass types have been selected as the choice of “pull” while lablab bean and green gram as the “push” companion test crops. Recent results have demonstrated that the lablab bean being more effective as the push crop while P. maximum does well as the choice “pull” grass in the in the marginal dry land environment of eastern Kenya. The findings here give direction towards which kind of push-pull technology might provide some reliable information on management of FAW in cereal production.

Livestock Keepers in Isiolo County, Embrace New Adaptive Strategies as Mitigation Measures against the Effects of Drought*Anastasia Kagunyu1, Steve Nangendo2 and Joseph Wanjohi3

1Kenya Agricultural and Livestock Research Organization- Sericulture P.O.BOX 14733-00800, Nairobi2 Institute of Anthropology, Gender and African Studies, University of Nairobi, P.O.BOX 8711 Nairobi3Catholic University of Eastern Africa, P.O.BOX 805-00200 Nairobi

*Correspondence author: kagunyu2010@gmail.com

Abstract Drought has become a perennial problem in Kenya with chronic vulnerability being concentrated in Arid and Semi-Arid lands (ASALs). Over recent years, pastoral communities have had to employ other supportive activities to supplement pastoralism, which has proved to be ineffective in meeting all their economic and social needs. There was inadequate information about the alternative adaptive strategies applied by the Borana of Isiolo in their response to the effects of droughts. As a result, this study was initiated whose overall objective was to investigate the new adaptive strategies being used by livestock keepers of Isiolo to cushion themselves against the negative impact of droughts. To achieve this objective this study applied household interviews, focus group discussions and key informant interviews to collect data. The results of this study revealed that the Borana Community has come up with new adaptive strategies which included causal labor, formal employment, small scale farming, small scale businesses, camel rearing, eating of wild edible plants and receiving assistances from development agents. However, it came out clearly that the alternative adaptive strategies the Borana community is engaged in are short-lived and not sustainable since the community has

limited skills and capital to enable it have better gains. This study therefore came up with some recommendations which include; the need for livestock keepers to be trained on appropriate skills on crop production and entrepreneurship, the need for development agents to include camels in their restocking programmes in the region. The need for pastoral community to be trained on the best methods of conserving wild edible plants and even planting drought resistance plants. There is also the need for the development agents to establish long term programs such as restocking with livestock species like camel which seems to be suitable for the dry lands and promoting water harvesting technologies.

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SUB-THEME 5:

Digital Soil Mapping, Precision Agriculture, Resource Inventory and Land Use Planning for Sustainable Food and Nutrition Security

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Spatial Vulnerability Assessment of River Mitano Catchment to Degradation in SW Uganda-Congo Boarder P. Musinguzi1*; B.Barasa2, John Kameri3, B. Atukwase3, E. Elizabeth Aisu3; S. Ogwete4; S. Opio4; W. Epalitai3; J.Okot-Okum5

1Department of Agricultural Production, Makerere University2Kyambogo University3Pinnacle integrated Resource Ltd4Ministry of Water and Environment 5Department of Environment Management, Makerere University

*Corresponding email: musipato7@gmail.com

AbstractLand remains a finite resource despite the increasing pressure from the rapidly growing human population due to high demand for water, food, fuel, fibre, fodder and better income. Pressure on land has resulted in negative impacts on water resources, ecosystem health and livelihood strategies. A spatial analysis of land use and related biophysical factors on increasing risks for productivity is important. A study was conducted in south western Uganda, along the River Mitano catchment, to analyze the level of vulnerability and risk of the catchment to degradation. A GIS environment supported the analysis. Results indicated that there is high variability in the vulnerability of the catchment to degradation with intensively cultivated most vulnerable. More than 30% of the land areas registered high risk for soil loss, sediment loading, low fertility and low crop productivity. Soil fertility has declined over 10 years with evidence by low productivity. Degradation along the hot spot regions have orchestrated wetland encroachment, with evidences of decline in the wetland cover and degraded boundaries Findings indicate that there is need for land use management interventions in hot spot zones for increased adaptation targeting soil management for reduced risks to land degradation

Planning for Land Degradation Neutrality in Nalwekomba catchment, Kamuli district UgandaIsabirye Moses1, Stephen Muwaya2, Mathias Magunda2

1Busitema University, P.O. Box 236, Tororo, Uganda2Ministry of Agriculture Animal Resources and Fisheries, P.O. Box 102, Entebbe, Uganda

AbstractLand cover has changed significantly in Nalwekomba catchment (21,800 Ha) over the past 7 years with possible decline of ecosystem and community resilience to the impacts of desertification, land degradation and drought. Interventions to avoid further net loss of Land-based natural capital are proposed in light of LDN wherein interventions are identified to counterbalance anticipated losses to achieve equivalent gains within individual land types. A neutrality mechanism balance sheet, a key input to the land use planning process, is proposed to track land condition in the catchment.

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Spatial Variability in Soil Properties and Plant Nutrient of Paddy Rice in Mwea, Kenya*1Kundu C. A., 2T. Masunaga, 2K. Sato, 2M. Ishii, 3A.Yamauchi, 4D. Makihara and 5R. K. Wanjogu

1Kenya Agricultural and Livestock Research Organization (KALRO), Box 169-50100, Kakamega, Kenya2Faculty of Life and Environmental Sciences, Shimane University, 1060 Nishikawatsu-cho, Matsue city, Shimane 690-8504 Japan3Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan4International Co-operation Centre for Agricultural Education (ICCAE), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan5Mwea Irrigation Agricultural Development Centre (MIAD), Box 210-10303, Wang’uru, Kenya

*Correspondence: carolinekundu@gmail.com, Tel: +254(0)708-693-185.

AbstractLowlands constitute major environment for rice cultivation in Kenya, but declining soil productivity has led to low poor quality yields. This study assessed soil and yield quality of rice in Mwea irrigation scheme. Surface 0-15cm soil was sampled for laboratory analysis. Rice straw and grain was collected and analysed for total nutrient. Results obtained for soil and plant were evaluated basing on nutrient guidelines for rice. Results indicated that soil pH was moderately high and salt concentration negligible (< 0.4 dS/m). Soil total carbon was moderately high while total nitrogen was low. Available phosphorus, sulphur and silica all exceeded deficiency level for rice. Exchangeable Ca2+ and Mg2+ dominated compared to exchangeable K+ and Na+; and as a result severe K+ deficiency because of cation imbalance existed. Among micronutrients, soil Fe, Mn and Cu were high while Zn was deficient. Grain yields were below optimum and plant analyses revealed deficiencies in straw total sulphur, K and Ca in some units. Grain samples showed deficiency in total Ca, Fe, K, Mg and S. Soil condition and nutrient concentrations affected nutrient accumulation in straw and grain. Appropriate soil management practices should be considered for improved quality and quantity of yields.

Biophysical production potential and zonation of Taita Taveta research sites for enhanced water and fertilizer use efficiency *1E.M. Muya, 1L.K. Tanui, 1I.V. Sijali, 1P. Kathuli, 1A.O. Esilaba, 1J. Miriti, 1D. Nyongesa, 1A.L.Chek, 1E. Thuranira and 1C. Githunguri

1Kenya Agricultural and Livestock Research Organization, P.O. Box 57811-00800, Nairobi

*Corresponding Scientist: edwardmuya2011@gmail.com

ABSTRACTThe improved water availability and fertilizer use efficiency through climate smart agriculture can be achieved through identification of cluster-specific biophysical constraints that impede the water and nutrient uptake through the plant roots. Therefore, using soil survey and land

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evaluation of the project sites, three clusters were identified as micro-management zones, namely: MMZ1, MMZ2 and MMZ3 with different degrees of soil structural deformation and rainwater uptake characteristics. The MMZ1 had the highest amount rain stored within the root zone and the lowest quantity of water wasted through run-off of only 11.1%, but with the lowest yield of 760 kg/ha. This could be attributed to relatively high acidity that needs to be reduced to an optimum level. The highest amount of rainfall was recorded in MMZ2, out of which 18.6% was wasted as run-off, while 652 mm was stored within the root zone giving rise to the production of 805 kg/ha of maize, which was only 10% of the potential yield. The MMZ3 had the lowest amount of rainfall of 597 mm but the highest production level of 3,952 kg/ha. This is because the 14.1% water lost through run-off was replenished through supplementary irrigation. The generally low maize production was attributed to reduced compounded sufficiency of the soil quality attributes for optimum plant growth with productivity index of less than 80% in all the three micro-management zones. The most limiting factors responsible for the low productivity index were found to be soil structural deformation, too low or too high soil pH, very low nitrogen and extremely low soil organic carbon. Therefore, the required interventions are aimed at improved soil structure for enhanced water and nutrient uptake through appropriate tillage practices. Organic matter was found to be the major input into soil structural improvement which would have a rippling effect on soil fertility with regards to increased supply of the limiting nitrogen and soil organic carbon. The soil pH must be corrected, not only to facilitate the release of nutrient to the plants, but also to enhance the microbial-activities which become suppressed when the pH is either to low or too high.

Innovative approach of predicting soil properties in the eastern slopes of Mount Kenyamanure Evans1, Csorba Adam2, Michéli Erika2

1Kenya Agricultural and Livestock Research Organization P.O Box 14733 KARLO Kabete, Kenya 2Szent István University, Department of Soil Science and Agricultural Chemistry, 2100, Gödöllő, Hungary

*Corresponding Author email: mutumaeva1977@gmail.com

AbstractThe expected growth of population and the need for more food make the knowledge of soil properties essential to maximise agricultural production on the currently available land. High costs of soil survey and laboratory measurements are among the major reasons of lack of sufficient soil information which is important for proper land management. In this research, an innovative approach comprising of an optimized soil sampling design, a rapid and cost efficient mid infrared spectroscopy and geostatistics based approach was applied to provide necessary soil data for proper land management in the eastern slopes of Mt. Kenya. Conditional Latin hypercube method was used to develop a sampling design that would ensure full coverage of environmental variables. Variables representing topographic parameters were generated by using digital elevation models. The KENOSTER map represented the soil information layer. Normalized difference vegetation index were generated from Landsat 8 imagery. The developed sampling scheme conserved the distribution of environmental covariates using box

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plots to validate. Soil spectra for the 232 samples collected from 77 georeferenced locations were measured using mid-infrared spectroscopic methods at wavelength range of 4000 - 400 cm-1. To select the calibration samples from the mid-infrared spectral database, principal component analysis and Kennard-Stone algorithm were used. Random forest regression was used to calibrate laboratory measurements to the soil mid-infrared spectra. Good spectral prediction model performance was achieved as follows: soil organic carbon and total nitrogen (r2 = 0.76, RMSE = 1.64 and r2 = 0.81, RMSE = 0.09) respectively, as well as for soil pH (r2 = 0.88 and RMSE = 0.48). Exchangeable Na, Mg, Al, K, Ca and extractable P were satisfactorily calibrated. Geostatistical analysis exhibited moderate spatial dependency of the soil properties. Soil properties were quantified and now can support soil management decisions for different agricultural value chains.

Macro and micro-nutrient status of some Kenya soilsJ. A. Omwakwe a*, Prof George N. Chemining’wab, Dr. A.O. Esilaba c, EG Thuraniraa

a Kenya Agricultural and Livestock Research Organization, Kabete. P.O Box 14733-00800 Nairobi Kenya. b Department of Plant Science and Crop Protection, University of Nairobi, P. O. Box 29053-00625, Kangemi. c Kenya Agricultural and Livestock Research Organization, Headquarters. P. O. Box 57811, City Square, Nairobi, 00200 Kenya.

*Corresponding author: addahjoyce@yahoo.com, Cellphone +254727901835

AbstractMacronutrients and micronutrients are important in enhancing crop productivity in Africa. A study was carried out to determine the macro and micro nutrient status of Kenya soils from 13 counties in Kenya. Twenty three surface soils (0 to 30cm) were collected and evaluated for, total nitrogen, total organic carbon, phosphorus, potassium, calcium, magnesium, manganese, copper, iron , zinc, sodium, electrical conductivity, cation exchange capacity (CEC), base saturation and soil pH. The mean values were 1200, 11100, 20, 8,105.3, 22.7, 4.4, 3.95, 52.78, 1.86,4, 1 mg kg-1, 0.11mS/cm, 11.98 Cmol (+)/kg, 83.13% and, 5.96 respectively. The soil analysis results indicated that nitrogen and phosphorous continue to be deficient in most soils in Kenya but potassium is mainly deficient in western Kenya. Sulphur and micronutrients (zinc) are deficient in some soils in Kenya. The soil chemical properties were correlated with each other and organic carbon showed significant and positive correlation with % nitrogen (r=0.991**), copper (r=0.533**), zinc (r=0.542**), CEC (r=0.456*) and exchangeable aluminum (0.586**). Available phosphorous showed significant correlations with sulphur (r= -0.656**), copper (r=-0.446) and exchangeable aluminum (r=0.612**). Potassium showed significant correlation with calcium (r=-0.522*), sodium (r=0.712**), sum of cations (r=0.551**), base saturation (r=0.615**), exchangeable sodium percentage (r=0.768*) and electrical conductivity (r=0.539*). Sulphur had significant correlations with copper (r=0.343*), magnesium (r=0.322**), exchangeable aluminum (r=0.616**) and electrical conductivity (r=0.3540). Manganese showed positive correlation with zinc (r=0.395*). Copper had positive correlations with CEC (r=0.347*), exchangeable aluminum (r=0.324**) and base saturation (r=0.316*). Iron was only positively correlated with zinc (r=0.656**). The exchangeable bases

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showed significant correlation with each other. Soil analysis determines the exact nutrient found in the soil. Research should focus on laboratory, greenhouse and field trials to correlate and calibrate the plant availability of macronutrients and micronutrients for site specific smart fertilizer recommendations in Kenya.

Soil erosion and deposition rates determined using Fallout radionuclides (Caesium – 137) in eastern and south western Highland of Uganda Kaizzi CK1*, Byalebeka JB, and Nansamba A

1National Agricultural Research Laboratories, National Agricultural Organization (NARO), Box 7065 Kampala, Uganda. Tel. 256772518875

*Corresponding author email: kckaizzi@gmail.com

AbstractLand degradation is a major threat to food, income and nutrition security in Africa south of the Sahara, with soil erosion from water as the most serious and extensive form of degradation. Soil erosion rates have been estimated using conventional methods with derived rates above 5 t ha-1 year-1 the tolerable rate for Uganda. Caesium -137 was used to estimate soil erosion and deposition R. Atari catchments and Kyokyezo located in eastern highlands and south western highlands, respectively. Conversional models namely; Proportional Model (PM), Mass Balance Model 1 (MBM I) and Mass Balance Model 2 (MBM 2) were used to estimate mean soil erosion rates. For PM the rates were 17.1, 5.1 and 104 t ha-1 year-1 for slopes in R. Atari catchment, floodplain of R. Atari and Kyokyezo, respectively; for MBM 1 the rates were 21.3, 6.1 and 156 t ha-1 year-1 for slopes in R. Atari catchment, floodplain of R. Atari and Kyokyezo, respectively and the rates for MBM 2 were 19.8, 4.3 and 28.4 t ha-1 year-1 for slopes in R. Atari catchment, floodplain of R. Atari and Kyokyezo, respectively. The percentage of eroded areas were 36%, 29% and 57% for slopes in R. Atari catchment, floodplain of R. Atari and Kyokyezo, respectively. The higher rates of erosion parameters at Kyokyezo compared to R. Atari was due to farmers in Kyokyeso abandoning and destroying terraces unlike in R. Atari catchment highlands which stresses the importance of soil conservation measures in reducing soil erosion. Reducing and preventing land degradation is important because of declining arable land per capita.

Analysis of soil potential for sustainable land use planning for the third crop in bunyala scheme 1*E.M. Muya, 1I.V. Sijali, 2M. Masaku, 3N. Korir, 1M. Otipa, 1H. Rotich, 1A.L Chek and 4C. Ngige

1Kenya Agricultural and Livestock Research Organization, Kabete Centre, P.O. Box 14733-00800, Nairobi2National Irrigation Board, P.O. Box 30372-00100, Nairobi3Kenyatta University, P.O. Box 43844-00100, Nairobi4Ministry of Agriculture, Livestock and Fisheries,P.O. Box 34188-00100, Nairobi

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*Corresponding Scientist: edwardmuya2011@gmail.com AbstractProduction system, consisting only of rice, supported by increased use of chemical fertilizers, is unsustainable. Therefore, alternative crops were sought through analysis and delineating the project area into soil clusters in terms of physical and chemical productivity index (PI) as a basis of land use planning for alternative crops. The results showed that the project areas selected for the third crop (i.e. cluster 3 and 4) had physical productivity (PI) of 67.8, being rated as marginally suitable for the envisaged crops. The highest physical productivity index was recorded in cluster 7 with value of 96.4%, followed by cluster 6 with PI value of 74.3%. Cluster 5 had the lowest physical PI of 60.1%, being rated as non-suitable. The most fertile soil was identified in cluster 7 with chemical PI of 94.1%, followed by cluster 6 with 75.8%. Cluster 3, 4 and 5 had chemical PI ranging between 50.0 and 57.8%. The differences in PI between different clusters are indicative of the potential differences in plant response to fertilizer application, thereby, invalidating the current blanket application of the agricultural inputs. Based on these potentials, appropriate land use options are provided as well sustainable land use plan and its implementation framework.

Excursion guide for the 29th soil science society of Eastern Africa (SSSEA) to be held on November 2019 in Naivasha, Nakuru County P.T. Kamoni1, E.M. Muya1 and J.M. Miriti1.

1Kenya Agricultural & Livestock Research Organization, KALRO Kabete, P.O. Box 14733-00800, Nairobi, Kenya.

*Corresponding author Email: pkamoni@gmail.com

AbstractThe conference will take place in Naivsaha town which is situated in Naivasha Sub-County of Nakuru County. The area for excursion will be within Naivasha Sub-County. The participants will go to Maraigushu, 2279 m above sea level (asl) and 14 km from Naivasha town to view and discuss soil profile number 1 (STOP 1). STOP 2 will be at Kinamba (2207 m asl) where the participants will be able to view Nakuru town, lake Naivasha and the donkey slaughter house. STOP 3 will be at Mr. Ngarama’s farm where participants will view and discuss soil profile number 2. Profile number 2 is in Mirera area near Lake Naivasha and is 495 m lower than the altitude of Profile number 2. From Ngarama’s farm the participants will then go to view and discuss soil profile number 4 which is on the geological fault line within the Rift Valley (STOP 4). Profile number 4 is located along Narok-Mai Mahiu road, 6 km from Mai Mahiu and 41 km from Naivasha town. The soil profiles will enable participants evaluate soil formation characteristics and factors that influence agricultural production in Naivasha Sub-County of Nakuru County.

Clustering soils for precision agriculture and enhanced crop yield response to water and fertilizer in Machakos County2E.M. Muya, 2I.V. Sijali, 2J.M. Mirit, 2L. T. Chirchir, 2P.N. Macharia, 1A.O. Esilaba, 2E.G. Thuranira 1H. Rotich, , 1D. Nyongesa and 1C.W. Githunguri

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1Kenya Agricultural and Livestock Research Organization (KALRO_, P.O. Box 57811-00800, Nairobi1Food Crop Research Institute, National Agricultural Research Laboratories, KALRO-Kabete

AbstractEfficient water and nutrient management through climate smart precision agriculture requires clustering of the production systems into micro-management zones, based on soil quality indicators that determine water and nutrient availability. The strategic clustering of agricultural systems was done by interrogating the farmers, soils and landscape features at high resolution and deciding on the locations which sampled all the differences likely to influence the water and nutrient uptake. High resolution quantification of these parameters was achieved through soil survey with geostatistical interpolation and ground-truthing of the selected datasets that included soil pH, balk density, soil organic carbon, run-off, macro- and micro-nutrients. The results showed huge gaps of maize yields which are attributed to soil structural and biophysical constraints whose spatial magnitudes and distribution are presented. Based on the cluster-specific recommendations, validation trials can be carried out in each of the clusters delineated as a basis of coming up with appropriate fertilizer blends to be applied in a broader geographical scale.

Participatory appraisal of integrated Vertisol management options for enhancing food security and income generation for Arid and Semi-Arid Lands in KenyaJoab Onyango Wamari*1, J.N.K Macharia 2, I.V. Sijali 1

1National Agricultural Research Laboratories, Nairobi, Kenya2 National Fibre Research Centre, Mwea Tebere, Kerugoya, Kenya

* Corresponding author email: joabwamari@yahoo.com | Tel.: +254-20-4444140-44

AbstractAlthough vertisol drainage has been recognized as the best option by ASAL farmers they do not appropriately use this. Farmers indicated unavailability of timely labour and costly institution of these practices as major hindrances against adoption but this can be offset by the relative advantages. Surveys using structured questionnaire, rapid rural appraisal and focused group discussions were used to prioritize vertisol management options between 2015 and 2017. Prioritized vertisoll management practices and appropriate agronomic practices were instituted and participatory assessed through farmer field school model and demonstrated enhanced production potential of maize and dolichos in Thika Kiambu County and green gram and tomato in Mwea

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Kirinyaga County. Crop yields improved by between 50 and 57% due to use of appropriate agronomic practices in Thika while green gram and tomato yields significantly increased by between 17 and 25% under application of farm-yard manure ridging and DAP combined at Mwea the later enhancing income by 67.7% and 45.9% for the respective crops. Institution of appropriate ridging, farm-yard manure and soil-related fertilizer use which enhance soil chemical and physical characteristics are recommended.

Exploring the potential of using Fallout radionuclides (Caesium – 137) to measure soil erosion and deposition rates in Uganda Nansamba, A., Kaizzi, C.K., Byalebeka, J.B.

AbstractSoil erosion from water as the most serious and extensive form of degradation in Uganda devastating rangelands due to overgrazing and cutting of trees for charcoal, and high population density, clearing of forests and cultivation of steep slopes in the highlands which cover 25% of the land in Uganda but support over 40% of the population. Soil erosion rates have been estimated using conventional methods with derived rates above 5 t ha-1 year-1 the tolerable rate for Uganda. In this study Caesium -137 was used to estimate soil erosion and deposition along R. Manafwa and R. Atari catchments, eastern highlands, and Kyokyezo, south western highlands. The exploratory study was carried out in R. Manafwa catchment running from Mt. Elgon to the low lying areas. The objective of the study was to (something is missing) where 137Cs was adequate and detectable in Uganda soils. Results indicated that 137Cs activity had accumulated to a detectable magnitude in Uganda soils. 137Cs activity was detected from the surface 2 cm layer down to the 70 - 75 cm layer in the floodplain of R. Manafwa. Indicating that 137Cs has over the years accumulated in the Manafwa River flood plain which was a result of deposition of soil eroded from the upper parts of the river catchment. Soil erosion and deposition rates estimated using Conversional models namely; Proportional Model (PM), Mass Balance Model 1 (MBM I) and Mass Balance Model 2 (MBM 2) were in the range (5 – 60 t ha-1 year-1) and (2 – 40 t ha-1 year-1) for soil erosion and deposition, respectively

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SUB THEME 7:

Socio-Economics and Policy Options in Land and Water Management

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Factors affecting adoption of Integrated Soil Fertility Management technologies in Kenya: A case study of Machakos and Bungoma counties.Rosemary Akhungu Emongor*1, Enid Katungi2 and Roselyn Uside3.

1Kenya Agricultural and Livestock Research Organization, Food Crops Research Institute, National Agricultural Laboratories Kabete, P.O. Box 14733-00800 Nairobi, email: 2 International center for Tropical Agriculture (CIAT), Kawanda National Agricultural Research Institute, P. O. Box 6247, Kampala, Uganda3 Kenya Agricultural and Livestock Research Organization, Non-Ruminant Research Institute-Kakamega, P.O. Box 169-50100, Kakamega, Kenya

* Corresponding Author: rosemary.emongor@kalro-org

AbstractCommon Bean is an important pulse crop in East Africa. Bean yields have been low and on the decline in Kenya. The decline in Bean yields has been due to biotic and abiotic stresses such as low rainfall, pests and diseases, low soil fertility among others. Research was carried out to determine factors that influenced adoption of Integrated Soil Fertility Management (ISFM) technologies in Bungoma and Machakos counties, Kenya. Multi-stage sampling procedure was used to randomly sample 502 smallholder farmers in Bungoma and Machakos counties. Primary data was collected from sampled farmers by carrying out face to face interviews using a structured questionnaire. Collected data was analyzed using descriptive statistics and Logistic regression. Descriptive statistics results showed that the adoption and use of ISFM varied in the two counties. For example, approximately 32% of farmers in Machakos County did not use ISFM technologies compared to 14% farmers in Bungoma who did not use ISFM technologies. Approximately 33%of sampled farmers in in Machakos County used manure compared to 8% in Bungoma County. The Logistic regression results showed that five factors significantly influenced the choice of ISFM by farmers. These factors were: region, level of education of the household head, access to extension services, whether the household was food secure and availability of markets for beans. The study concluded that farmers in the two study sites were adopting and using ISFM in their bean production process.

Unseen value of trees in indigenous agro-forestry systemsArmstrong B. Atugumya and Moses Isabirye

Faculty of Natural Resources and Environmental Sciences, Busitema University, Uganda

AbstractFarmers’ knowledge is essential in order to comprehend the possible barriers and opportunities to carrying out sustainable tree-crop management while mitigating the impacts of climate change. However, there are several non-tangible benefits of trees that go unnoticed and therefore cannot contribute to a comprehensive valuation of trees. By assessing the influence of tree cover on below ground biodiversity, this study explores the gap in the valuation of trees by farmers basing on tangible values of trees and their influence on Below Ground Biodiversity (BGBD) and crop performance. Willingness to Accept (WTA) valuation method was used to capture farmer’s perception and market price for Crop performance. Tree canopies influenced

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the productivity of soils through the high activity of soil organisms that in turn contributed to the total value of trees. Soil organisms explained 99% of the variations in the spatial distribution of soils (P < 0.05; 0.000 < 0.05).

Adoption of Postharvest handling Technologies of Passion Fruits (Passiflora edulis Sims var.) by farmers in Uasin Gishu County

1Lagat, Cyrus K.; 2Omami, E.N; 2Mutui, T.M. & 3Kimani, S.

1Research Intern, KALRO Soin ATC or Seed, Crop and Horticultural Science Department, University of Eldoret2Seed, Crop and Horticultural Science Department, University of Eldoret2Seed, Crop and Horticultural Science Department, University of Eldoret3Senior Research Scientist, KALRO FCRI Muguga

AbstractIn Kenya, Passion fruit is becoming part of solution in staving- off hunger and malnourishment. Most of the underutilized fruits passion fruits included are often among those which have the greatest potential in terms of nutrition and income generation for small holders. Passion fruit is underutilized because of the significant amounts that go into waste during peak production. The objective of this study was to evaluate how farmers harvest their produce, their postharvest handling technologies as well as establish their mode of storage of passion fruit (Passiflora edulis Sims var) in Uasin -Gishu County. A total of 77 farmers were interviewed in Soy and Kapsaret sub-counties in Uasin Gishu County. The survey was conducted using a semi structured questionnaire administered through snow ball sampling technique .The data collected was subjected to descriptive IBM SPSS statistics 21. The study has showed that Most of the farmers in Uasin County have entered into passion fruit production enterprise without proper passion fruit postharvest handling knowledge. Farmers are encouraged to embrace new harvest and postharvest handling technologies if they are to reduce Passion fruit postharvest losses.

Distance effects on On-Farm Tree diversity and soil organic carbon stocks in Nandi-Kakamega Forest EcosystemMuigai Pauline1*, Obiri John2, Otuoma John3, Agevi Humphrey1 and Ayaga George4

1 Department of Biological Sciences, Masinde Muliro University of Science and Technology (MMUST)2School of Disaster Management and Humanitarian Assistance, Masinde Muliro University of Science and Technology (MMUST)3Kenya Forestry Research Institute (KEFRI)4Kenya Agricultural and Livestock Research Organization (KALRO), Alupe Busia

*Corresponding Author: muigaipolyn@gmail.com

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AbstractForests provide invaluable ecosystem goods and services that most forest adjacent communities (FAC) have solely been depending on for improved livelihoods. Increasing human population and especially around the forests has however exacerbated most pressure on these precious resources. This in turn has resulted to continuous decline in forest cover hence affecting forests ecosystem health. Attention has however been drawn to trees on farmlands and their contribution to enhancing tree diversity and soil carbon stocks. These trees are either planted by the farmers or some regenerate from the seed bank or through seedling dispersal mechanisms. Most farmers prefer however those tree species that are fast growing and have high economic value. This study therefore sought to find out trends in tree diversity and soil organic carbon (SOC) stocks with increasing distance from the Nandi- Kakamega Forest ecosystem. Three sites within Kakamega, Vihiga and Nandi counties were chosen from the edge of the forest, 5km towards farmlands within micro catchments that had been established by the GEF project. These were near the forest, mid and away from the forest. In each of the sites, tree type and number was determined. Soil samples were taken at 0-15cm and 15-30 cm in each site, pooled together and a composite sample taken for the respective depth. Tree diversity was determined by using shannon weiner diversity, soil pH was determined insitu, SOC was analyzed using the walkley-black method. Differences in the parameters was determined through calculating ANOVA at 0.05. A mixture of indigenous and exotic tree species were sampled with indigenous being abundant in the three sites. Eucalyptus saligna dominated the farmlands (N=248). Tree diversity was higher in Nandi (H’=0.657) and lowest in Vihiga (H’=0.568). Distance from the forest did not have significant effect on tree diversity in all the sites. Soils in the 0-15cm depth had higher SOC than the 15-30cm depth. Nandi site had the highest SOC (34.75%) while the least was Vihiga (23.14%) in the upper depth. The difference in SOC stocks exhibited was significant in all sites and at the two depth except in Nandi and Vihiga at 15-30cm depth. There is need to enhance tree diversity on farmlands to enhance carbon stocks which will mitigate against climate change

Crop – livestock integration systems in mountain areas of Northern kenyaDuba Golicha1 and Hassan Charfi2

1Kenya Agricultural and Livestock Research Organization, Marsabit Research Centre. P.O. Box 147 – 60500, Marsabit, Kenya2Ministry of Agriculture, County Government of Marsabit

*Corresponding Author: golichdub@yahoo.com

AbstractThe mountain areas of northern Kenya is inhabited by agro-pastoralists. Small-scale crop production and livestock keeping is the main sources of livelihoods in the arable mountain areas of northern Kenya. Using structured questionnaires, this study clarified whether there is interdependencies among the crop and livestock components of the farmers in arable northern Kenya. The area of interactions for crop-livestock systems of northern Kenya include: farm power, use of crop residues, manure for field’s fertilization and cash-flows between crop and livestock component. In arable mountain areas of northern Kenya, animal power is mainly used for farm operations like ploughing, and also donkeys are used watering livestock. Nevertheless, 93% of interviewed farmers use people-power while 40% uses animal-power. Furthermore,

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during the long rain season, the time of planting is in the month of March for farmers with oxen (animal power) and in the Month of April for the farmers without oxen. Additionally, 71% of interviewed farmers use crop-residues for feeding livestock with negligible amount of crop-residues availed for field’s fertilization. The study also revealed inefficiency in the utilization of manure. In fact, only 43.4% of interviewed farmers use the manures for fertilization, while others throws the manure away. In a nutshell, the crop-livestock systems of arable northern Kenya, lacks the beneficial interconnectedness between the crop and livestock components. The minimal utilization of manure and out-flow of crop-residues into livestock component can result into nutrients imbalance. In-depth research into nutrient flows and capacity building on sustainable crop-livestock integration is necessary for farmers in arable mountain areas of northern Kenya.

Demographic and socioeconomic factors influencing uptake of striga control technologies in western KenyaGodfrey Nakitare Nambafu1* and Richard Ndemo Onwonga2

1University of Kabianga, Department of Agriculture Biosystems and Economics, Kenya, P.O Box 2030 – 20200, Kericho, Kenya. 2 University of Nairobi, Department of Land Resources Management and Agriculture Technology, KenyaP.O Box 29053 – 00625, Kangemi, Kenya. dr.onwonga@gmail.com

* Corresponding Author: nambafugodfrey@gmail.com

AbstractOver the years, new technologies have been tested and introduced to control Striga in maize producing areas but adoption has remained low. The study done in 2013, determined the demographic and socioeconomic factors that influenced the adoption of Striga control technologies in Kisumu West, Bumula and Teso South sub counties of Western Kenya. Through Multi stage sampling technique, 40 households were selected per sub county for questionnaire administration to gather information on demographic profiles of the sample population, type of fertilizer and seed variety used, income of the household, source of credit facilities and challenges faced in weed control. Chi square test at P<0.05 and logistic regression analysis, using R software was used to determine the relationship between demographic and socioeconomic factors and uptake of Striga control technologies. Farmers cited high cost, poor availability of improved varieties and lack of adequate knowledge as reasons for non-adoption of the Striga control strategies. Farmer’s age, education, land size, and hiring of labour were found to significantly influence the adoption of the Striga control technologies. The low levels of adoption of modern technology indicate that they were not meeting farmers’ expectations, thus, researchers should put into consideration farmers’ education, age, land size and ability to high labour in their planning for an informed technology adoption. In addition, alternative options should be extended to farmers who are not able to use expensive technologies.

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Opportunities of enhancing smallholders’ agricultural productivity through irrigation: The case of Uganda Francis M. Mwaura

University of Eldoret, P.O. Box 1125 Eldoret Email: mungaimwaura@yahoo.com

AbstractOvercoming challenges presented by vagaries of weather remains a significant intervention in enhancing agricultural productivity, farmers’ incomes and economic growth for most developing countries. In Uganda, strategies for intervention are hindered by lack of countries with similar socio-economic, environmental and economic characteristics to benchmark from. This paper proposes adoption of supplement irrigation water provision as a utility being the ultimate intervention of enhancing agricultural productivity among smallholder farmers in Uganda. It uses nationwide surveys, administrative data and expert consultation to show the rationale for irrigation, existing potential of supplemental irrigation, and to provide commercial and operational basis for adopting proposed system.

The climate benign natural green technology for wastewater treatmentLucy Wanjohi*1, Shem Mwasi 1 and Lizzy Mwamburi 2

1 Department of Environmental Biology and Health, School of Environmental Studies University of Eldoret, P.O. Box 1125-30100, Eldoret 2 Department of Biological Sciences, School of Science, University of Eldoret, P.O Box 1125-30100, Eldoret

Abstract Water is a vital, indispensable resource which organisms requires for the sustenance of life. Currently, problem of water scarcity persists due to water pollution by heavy metals and eutrophic nutrients that has resulted in degraded environment and adverse effects on biota. Conventional methods are employed to remove heavy metals from wastewater but are un-economical especially while the metals are in low but significant concentration. Alternative method is phytoremediation which effectively removes pollutants from environments. This research was carried out to establish the ability of macrophytes to remediate pollutants from wastewater. Locally available macrophytes which included Azolla pinnata, Typha latifolia, Nymphaea spp. and Ceratophyllum demersum were collected from Marura wetland and identified. Wastewater samples were collected from University of Eldoret sewage treatment plant. Water indicator parameters, nutrients and heavy metals were determined using standard methods. Growth chambers containing wastewater samples were prepared in the laboratory. Macrophytes were established in these chambers. Wastewater analysis was carried out initially on setting up the experiment and then after every five days for 25 days to determine the changes in the levels of the parameters investigated. Means of mentioned parameters were calculated and analyzed using ANOVA and significant means separated using Tukey’s test at 5% level. Reduction efficiency was calculated. The range of removal efficiency of the investigated parameters was as follows; TDS 66.01-74.03%, pH 18.15-20.30%, conductivity 51.79-57.11%, turbidity 67.55-86.10%, faecal coliforms 100%, phosphates 88.65-100%, nitrates 89.38-100%, cadmium 88.96-92.19%, copper 78.87-85.86%, nickel 100%, cobalt 94.67-95.04%, lead 100%,

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manganese 85.81-88.81%, zinc 91.78- 93.64% and iron 85.81-88.81%. There were significant differences in reduction of phosphates, nitrates, lead and cadmium among the macrophytes, (P = 0.00). The macrophytes were found to be efficient in wastewater treatment. The order of removal efficiency was Azolla pinnata > Nymphaea spp > Typha latifolia > Ceratophyllum demersum. These macrophytes can be used to treat domestic, agricultural and industrial wastewater.

Farmer awareness and adoption of Finger Millet (Eleusine coracana) varieties in Bomet, Kenya.Jayo Manyasi Tracyline1, 2,, Paul Kimurto1,3, Joseph Mafurah1,2, Nancy Mungai1,2 and Bennard Towet1, 3

1Department of Crops, Horticulture and Soils, Egerton University,2Grain Legume and Dryland Crop Improvement Project (GLDC) 3International Crop Research Institute for Semi- Arid Tropics (ICRISAT)

*Correspondence: tracyjayo@gmail.com

AbstractFinger millet is a highly valued crop nutritionally and there are a number of constrains that hinder farmer adoption, awareness, production and further improvements. Twenty five finger millet varieties including three checks were evaluated in a 5 x 5 balanced alpha lattice design with three replications by farmers on a farmer field trial with an objective of assessing level of awareness and adoption of released and local finger millet genotypes in Bomet, Rift valley Kenya. Focused group discussion were conducted where 30 farmers grouped into groups of five evaluated the varieties based on high yielding, early maturity, drought tolerance, resistance to diseases, marketability, big fingers, resistance to lodging, tillering ability and uniformity. The data collected was subjected to Statistical Package for Social Sciences (SPSS) version 20 and analyzed using Kruskal Wallis test of non- parametric data. Uniformity, drought tolerance, tillering ability, big fingers, high yielding, resistance to lodging, marketability, early maturing and resistant to blast were the most preferred traits to farmers. Farmer participatory pointed out the varieties that performed best in each of these parameters. The varieties which performed the best included U15, Katfm1, Kne741, Gulu-e, Nkrfm1, Kne 629, P224, KATFM1XU15, IE2872, Etiyo brown, Kaldokolo, Kalpader and Kal2pader. The findings presented an urgent need for dissemination of information starting from the stakeholder’s levels, breeders, extension officers and farmers in general in order to make further improvement of finger millet and increase its production and consumption.

Does access to climate information affect adaptation decision? Case of smallholder farmers in South Eastern Kenya.*Stella Matere, 2Kizito Kwena, 3Hezron Mogaka, 4William Ndegwa, 1Tabeel Nandokha

1*KALRO-Food Crops Research Institute, Muguga South Centre,P.O. Box 30148-00100, Nairobi, Kenya

*Corresponding author: stellamatere@gmail.com

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2KALRO-Arid and Range Lands Institute, Katumani Centre, P.O. Box 340-90100, Machakos, Kenya3University of Embu, P.O Box 6-60100, Embu, Kenya3Kenya Meteorological Department, P.O. Box 30259-00100, Nairobi, Kenya

AbstractThis study was conducted in South Eastern Kenyan region to establish the type of climate information accessed by the smallholder farmers, the channels used to disseminate the information and use of the information in farm activities. Primary data was collected through a semi-structured questionnaire administered on 630 households in Machakos, Makueni and Kitui Counties. The results showed that 58 percent male and 17percent female headed households got climate information. Seasonal weather forecast provided information on onset and cessation of the rains, total amount of rain expected and warning on extreme floods or drought. Radio was the most popular channel of disseminating the forecasts in 36.3 percent male headed households and 2.4 percent female headed ones. Most female headed households got seasonal forecast from farmer groups. There was a statistically significant association of gender of household head and information disseminating channel. The weather forecasts were accompanied with agro-advisories on which appropriate crops to grow and other appropriate farm management aspects. Advisories for the seasonal forecasts was used in 45.8 percent male headed and 14.4 percent female headed households to acquire suitable seeds and fertilizers for the season, construct or repair the soil and water harvesting structures on farm, However, 20.4 percent, 15 percent and 10 percent of the households found the forecasts too general and not specific to their farming needs, unreliable and difficult to understand respectively. Capacity building of the farmers on interpretation of the weather information and its application in farm decision marking and the use of index-based insurance to cushion against the climate is necessary to enhance farmers’ resilience to climate change. There is need for providers of climate information to supply salient and credible information to enhance effective application of the information in farm adaptation decisions.

Cost and benefit analysis of conservation agriculture among smallholder maize farmers in Kakamega and Bungoma counties, KenyaL.M. Wafulaa, S.M. Wangiaa, A.O. Esilabab, D. Nyongesab

aDepartment of Plant Science and Crop Protection, University of Nairobi, College of Agricultural and Veterinary Sciences.P.O Box 29053-00625,Kangemi.bKenya Agricultural and Livestock Research Organization, Headquarters. P.O Box 57811, City Square, Nairobi, 00200, Kenya.

*Corresponding Author:wafulalameck@yahoo.com,lameckmukoya@gmail.com,+254700766800

AbstractThe Adoption and implementation of conservation agriculture principles has remained largely minimal in Africa, owing to debates whether the practice is a viable option for small scale resource poor farmers or not. The economic viability of practicing conservation agriculture has not been quite well demonstrated at small-holder farm level. This paper assessed the costs and benefits associated with adopting conservation agriculture practices in Kakamega

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and Bungoma counties. The study was conducted during the month of March 2018 through a household survey on farmers in the two counties that captured information on costs and benefits across two preceding seasons. Data was collected by well-trained enumerators drawn from the local area using semi-structured questionnaires. The results revealed that both conventional and conservation agriculture in the two counties had positive Net Present Values. The Internal Rate of Return values were less than the discounting rate over their lifecycles. Conservation agriculture farmers from Bungoma County had the highest NPV (US$ 389.78 acre-1 yr-1). Conventional farmers from the same county had an NPV of (US$ 286.999 acre-1 yr-1) For Kakamega County; conservation agriculture farmers had an NPV of (US$ 312.56 acre-1 yr-

1) with their conventional agriculture counterparts realizing an NPV of (US$ 267.719 acre-1

yr-1). The NPVs for Kakamega county also indicated that both systems were profitable but conservation agriculture farmers realized better economic returns(US$ 312.56 acre-1 yr-1) than their counterparts who practice the traditional method of farming that had an NPV of(US$ 267.719) The implementation of conservation agriculture principles in Bungoma county resulted in an IRR of 7.55% and 4.59% for conventional. The same trend can be realized in Kakamega County where the IRR for conservation agriculture farmers is 7.63% and 4.87% for their conventional counterparts.

Socio-economic evaluation of the effects of different sources of inorganic fertilizers on maize yield in North Rift KenyaWanyama J M. 1*, Mutoko, M.C. 1 Koech M.K. 1, Ndungu M.K.W 1, Kamidi M. 1 Wanjekeche, E. 1 Barkutwo J. 2, Esilaba, A. 3, Nyongesa D.W3, and Githunguti C. 3

*Corresponding author: Japheth.wanyama@kalro.org. or masindewanyama@gmail.com.

1Kenya Agricultural & Livestock Research Organization (KALRO), Food Crops Research Institute (FCRI) Headquarters, Kitale, Kenya2Kenya Agricultural & Livestock Research Organization (KALRO), Headquarters, CRI P. O. Box xx, Kitale, Kenya3Kenya Agricultural & Livestock Research Organization (KALRO) CRF- Kitale, P. O. Box 14733, 00800, Nairobi, Kenya

Abstract Chemicals fertilizers place critical role in achieving higher cereal yield. Non-economic viability of developed and deployed cereal technologies led to low/non-adoption of agricultural technologies. KCEP conducted on-farm validation trials in eight counties in Kenya including North Rift (Trans Nzoia and Nzoia counties. The treatments were laid-out in split plot design. Mother and bay design was utilized. The aims of these demos were to assess the technical, economic viability and famer preferences & knowledge of the technologies. Primary and secondary input-output data were collected per treatment and by experiment. Quantities of inputs and outputs were collected and valued. Farmers rating on treatment performance were also collected. For farmer evaluation two blocks (with lime and without lime) were randomly selected from the mother and baby trial and used for evaluation. The experiments on fertilizer sources main plot and Lime and No lime in the subplots. Data analysis was mainly descriptive. Partial budget and marginal analysis were utilized. The results for farmer evaluations were showed that the most preferred fertilizer types were Di-ammonium phosphate (DAP), MEAmazao and mavuno and farmers are brand conscious. The results on economic analysis

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revealed that the control, with some exceptions lime plus inorganic fertilizer gave the highest net benefits. The results of this study could be used for validation of the promising options and planning of future experiments.

Trends in soil science research in Kenya for the last 90 years – the missing gaps*1Esther Uchi Mumba and, 1Charles KK Gachene*1esthermumba61@gmail.com Corresponding author and MSc Soil Science student, Dept of LARMAT, University of Nairobi, P.O. Box 29053-00625, Nairobi1gachenecharles@gmail.com, Dept of LARMAT, University of Nairobi, P.O. Box 29053-00625, Nairobi

AbstractSince the 1900’s to the present, many journal papers, conference proceedings, students’ theses, bibliographies with annotations in the field of soil science have been presented and or published covering a wide range of soil science topics. These publications, and by no means not exhaustive, were analyzed according to the several fields of soil science that include Soil fertility, Soil biology, Soil Physics, Soil chemistry, Soil conservation, Irrigation and drainage, Tillage, Soil survey and land evaluation and Soil genesis and classification. For each of these categories, attempts were made to include other details such as location, year when the study was undertaken, soil type, crop under investigation. Research by fields shows that it is heavily biased towards soil fertility and that maize and beans are the most studied crops. Early studies during the colonial times were biased toward coffee and tea. About 80% of the publications were on Nitisols, Ferralsols, Vertisols, and Luvisols, representing both sub humid and semi-arid areas. In the early years, research was concentrated in field stations and were largely based in soil fertility. In this analysis, over 50% of the publications reviewed were on soil fertility, mainly addressing N and P. This analysis raises more questions than answers, for instance what has not been known with regard to N and P considering studies on these two elements have been and continue to be done since the last 90 years? Could this be at the expense of other, but very important elements such as the micro nutrients? As soil scientists, are we forgetting to address other important fields such as tillage and soil genesis? Could this be some of the reasons why we are yet to narrow the gap in yields? By mid-1930’s, the country was still experiencing soil erosion problems. Today it is still the same story. Could this be another example where there has been less emphasize on other branches of soil science such as soil conservation that is known to have a huge impact on soil productivity?

Is indigenous poultry production a suitable diversification strategy in the wake of climate change in semi-arid Kenya?Tabby Karanja–Lumumba

1Kenya Agricultural and Livestock Research Organization, Veterinary Science Research Institute, P.O. Box 32-00902, Kikuyu, Kenya

*Corresponding author: tabbydk@yahoo.com

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AbstractThis paper presents the case of 486 randomly sampled indigenous poultry producers from South Eastern Kenya to assess the suitability of indigenous poultry production as a diversification strategy in the wake of climate change. Among other results, the study revealed that indigenous poultry can be kept in a wide range of agro ecological zones, was kept and owned by male and female adults, male and female youth, the landless and those owning land hence can be kept by every person and termed as ‘every person’s livestock’, was largely kept at a subsistence scale but has potential for year-round production to generate cash income to meet household needs. The paper recommends promotion of indigenous poultry production alongside land and water management technologies as a suitable diversification strategy to enhance adoption of improved poultry technologies and catalyze transformation from subsistence to commercial production.

Fencing lands to Enhanced Climate change Resilience, promoting biodiversity regeneration and Improved Livelihoods of climate change in Migori CountyJustine T. Kurui, CEO and Francis Keya, Project Manager

African Alliance for Health, Research and Economic Development (AAHRED)

AbstractKenya is food insecure country, weather patterns are drastically changing and people are losing livelihoods and hard labor earnings when their lands dry, water for domestic supply lacking and livestock die further frustrating livelihoods of the poor. We do practical surveys, observation and research on practical concerns as climate change affecting food security. Food insecurity and poverty aggravated by high vulnerability due to impacts of climate change in rural communities in Kenya which on our findings reveal the grave environmental problem of climate change and how mitigation resilience and adaptation is necessary and can be fast tracked through regenerative agriculture requiring Fencing of lands as prerequisite to biodiversity protection and faster water retention mechanism enhancing tree planting enhancing CO2 sequestration as trees, shrubs and vegetation’s find suitable environment to grow. Baringo and Makueni County is characterized by unsustainable agriculture, environmental degradation resulting from soil erosion, high poverty levels and food insecurity due to unpredictable dry spells and climate change. There exists variability to rapid population growth which is worsened with cultural demand practices demanding constant supply of livestock and food to pay for dowry by young men in baringo hence resorting to cattle rustling leading to communal conflicts and wars to conflict over dry rivers and overharvesting that make it impossible to retain water in rivers. The vulnerabilities is compounded with the poor capacity to address climate change in rural communities increasing its ability to conservation agriculture practices on individual smallholder farms as a key response to addressing climate change impacts and habitat degradation for increased food security and economic incomes of communities in these Counties. With Fencing of lands comes improved agricultural land management practices and better pasture management and biodiversity growth leading to increased soil carbon sequestration and avoided deforestation and degradation, and reforestation activities on practical sense is a manner to do regeneration agriculture and enhance capturing CO2 from the atmosphere while sand dams enhance water retention and slows drying of rivers. There is evidence that sand and

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protection of rivers can quickly lead to improved water retention and seasonality of water. The capacity to protect land from interference and planting trees play a crucial role in ameliorating climate change by CO2 sequestration where CO2 from the atmosphere is stored as carbon in stems and roots, thereby reducing the greenhouse effect. Trees also influence hydrology by absorbing, intercepting and storing precipitation, and releasing water to the atmosphere through transpiration, maintaining ground water levels and reducing runoff. Trees are a source of food, shelter, and habitat for many organisms and soil erosion has contributed to desertification, growing water scarcity, and climate events such as flooding, storms and final loss of biodiversity.The fence and the sand dams seek to renew, restore and enhance trees growth, organisms, and ecosystems or biological systems. Fencing helps regeneration increasing soil biodiversity and organic matter, leading to more resilient soils that can better withstand climate change impacts like flooding and drought. It stops loss of the humus leading to healthy soils resulting to strong plant growth and nutrient-rich crops, diminishes erosion and runoff, leading to improved water quality on and off the farm and water sources and help us fight the climate crisis by pulling carbon from the atmosphere and sequestering it in the ground. Open Lands have in pastoral communities has paved way for Continues loss of livelihoods, agricultural produce and unending dry spell triggered with lose of top soils , drying of rivers and desertification Awareness and advocacy for Governments to promote land fencing , wetlands protection, strong policy formulation to reduce sand harvesting in rivers and investing in building sand dams critical for quick recovery of our rivers ability to retain water. The land fencing protect growth of plants and trees while sand dam’s stops water from running and sipping through the earth and rocks and getting retained in the dams for domestic supply and agricultural use.AAHRED working with grassroots implementers so that knowledge is disseminated in local dialects to bring about knowledge on the impacts of land fencing for conservation and climate mitigation and interventions through practical solutions that act as climate mitigations and link scientific knowledge to demystify climate change understanding and solutions at the rural level.

Assessment Economic, Social and Environmental Impacts Land Degradation in KenyaWellington M. Mulinge, Lucas Tanui and Antony Esilaba

AbstractLand degradation is widely recognized as a global problem associated with desertification in arid and semi-arid zones, which cover about 47% of the globe’s total surface area (UNEP, 1997). This is considered to be highly variable arising from different causes and affecting people differentially according to their economic and social circumstances. According to Thomas, et al., (1997), land degradation affects a large number of people over a significant proportion of the earth’s surface which has led to extreme poverty and hunger. This is associated with declining status of natural resources, and environmental un-sustainability. Evaluating the economic and social benefits and costs of land degradation can show governments how these problems relate to the economic development of their countries and the agency of putting in place policies that create an enabling environment to tackle the problem. The objectives of this study include: Review the extend of land degradation and assess the costs – economic, social and environmental Land Degradation and Drought in Kenya; Evaluate the status current programmes for application of SLM innovations towards the achievement of Land Degradation

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Neutrality (LDN), and Assess the effectiveness of policy in creating an enabling environment for development and application of SLM degradation in Kenya. Soil erosion risk mapping revealed that almost all the counties in Kenya are at risk from one form of land degradation or other. The problem is serious because high land degradation is likely to occur on about 61.4% the total area of Kenya, while very high degradation affects 27.2% of the land. Land degradation affects especially the ASALs, where the soils are highly erodible. The causes of land degradation in Kenya are both natural and human induced. They include biophysical (natural) factors related to climatic conditions and extreme weather events such as droughts and floods, and catchment factors such as steep slopes and highly erodible soils. Estimates of the direct costs of national land degradation as a proportion of national income have also been made for single countries, many referring to conditions in the 1980s. Other non-peer-reviewed estimates of direct costs are based on simulations of possible future trends, e.g. 8% of GDP in Niger (Nkonya et al., 2011), or refer to only one form of land degradation, e.g. 0.7% of GDP for the cost of overgrazing in Kenya (IMF, 2010. An analysis of the legal, regulatory policy and socio-economic issues impacting on land degradation and SLM revealed that there were multiple laws, policies, strategies, development plans and institutional frameworks addressing land degradation and/or SLM either directly or indirectly. However, few Government Departments have put resources into SLM implementation, and even this, addresses mostly large infrastructure developments, e.g. dams. But, gaps also exist in terms of addressing sustainable land management in agricultural systems. Furthermore, there is no one stop-shop to address targeted investments for SLM for smallholder land users.

Assessment of factors influencing mechanization levels of maize value chain in Trans Nzoia County, Kenya *Charles Bett, Noah Wawire, Susan Maingi and Eliud Rotich

Agricultural Mechanization Research Institute KALRO Katumani Research Centre P. O. Box 340-90100, Machakos, Kenya

*Corresponding Author: Charles.Bett@kalro.org

AbstractAlthough there have been several efforts by the government, voluntary and non-governmental organizations to promote use of agricultural machines in Kenya, level of mechanization and productivity in the maize value chain remains low. The low agricultural productivity has been associated with low levels of mechanization among other factors. The goal of this study was to assess the levels of agricultural mechanization in maize value chain in Kenya and make appropriate recommendations. A multistage sampling procedure was adopted in selecting respondents. The first stage of sampling was random selection of the sub-counties and the second was the sub-locations and lastly the farmers. Data was collected at three levels, secondary sources through desk reviews, key informants interviews using checklists and data collection from farmers using semi-structured questionnaires. Farmers were categorized into three levels, small, medium and large scale on the basis of area under maize. Results obtained revealed high level of mechanization across the three categories of farmers during ploughing with 95%

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of farmers using tractor during ploughing. The other farm operations, however, were largely manual, with less than 10% of the farmers harrowing before planting. While 42% of the large scale farmers used a tractor planter, majority of medium and small scale planted manually, either using hoe or using oxen to open furrows then plant. Similarly chemical weeding was practiced by 13%, 40% and 57% of small, medium and large scale farmers respectively. Topdressing and manure application was done manually by majority of the farmers. Harvesting and drying was done manually but shelling was highly mechanized with 86% of the respondents using a maize sheller. A regression model was estimated and important factors influencing levels of mechanization were age of the respondent, access to credit and costs of ploughing. The government should design strategies to provide incentives to bestow land ownership to the youth, improve access to credit and reduce costs of mechanization.

An economic assessment of Moringa Oleifera in Kenya’s cropping systems within the semi-arid regions for food security and improved livelihoods under climate change and variabilityDave Nyongesa1*, Eston Njeru1, Innocent Kariuki1, Haggai Ndukhu2, Peter Maina3, Sam Wambugu4 and Titus Chomba5

1Kenya Agricultural and Livestock Research Organization; P.O. Box 14733-00800, Westlands, Nairobi; P.O. Box 27-60100, Embu & P.O. Box 30148-00100, Nairobi. 2Chuka University, P. O. Box 109-604003Anglican Development Services–Mt Kenya East; P.O. Box 2376-10140, Nyeri; Kenya Industrial Research Development Institute, P.O. 30650-00100, Nairobi; 4Kenya Organic Agriculture and Environmental Technologies Institute, P.O. Box 19844-00100, Nairobi.

*Corresponding Author: Dave.Nyongengesa@kalro.org

AbstractThis study was undertaken in Embu and Tharaka-Nithi Counties, The goal was to enhance the contribution of Moringa Oleifera to soil health, climate resilience and community livelihoods in Kenya. Both purpose and multistage sampling techniques were used. It covered 430 households from 49 villages. Data was collected in two weeks (30/7/2018-9/8/2018), by 20 recruited and trained enumerators. It used a pre-tested semi-structured questionnaire with both open-ended and close-ended questions. Data analysis involved statistical and gender analyses. The results indicate Moringa establishment was between 1986 and 2018. However, 87.4% was between 2008 and 2018. Planting materials included seedlings (57.6%; seeds 41.2% and cuttings (1.2%). The trees established ranged from one-800 with a mean of 8 trees. The planting materials were from neighbours (45.9%), own (25.4%), government organizations (10.7%) and NGOs (5.6%). The producers were adult males (55.0%); adult females (30.0%); male youths (12.0%) and female youths (3.0%). Moringa information was from neighbours (52.0%), own (23.0%); forest department (14.0%). Farmers face many challenges that they ranked as either “high”; “medium” or “low” and also suggested some potential solutions to the identified challenges. Sensitization/training of farmers (40.8%) on Moringa agronomy and benefits was the major solution. Only 29.6% of the farmers did value addition. The Moringa benefits were as: food and source of nutrients (34.1%); medicine in curing many diseases and water purification (14.0); medicine alone (13.6%) and medicine, and food (11.2%). Moringa

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also played a role in helping the vulnerable groups (52.5%); soil conservation and fertility management (28.6%), and mitigating effect of Climate Change (25.7%). Moringa could be a panacea to malnutrition problems in Kenya, which stands at 53.0%, contributing to Vision 2030 and the Big Four if the governments provided a conducive environment/policy direction on it and farmers adoption its cultivation.

The Soil Science Society of East Africa (SSSEA)