Ramanjaneyulu

Rainfed Agriculture needs special dispensation

• Limitations of rainfed areas– Moisture– Soil fertility– infrastructure– Other income generating options

• Lack of public policy support– Technology development– Marketing– subsidies

What we should think of ….

• Integrated farming systems integrating livestock, trees etc

• Building soil organic matter

• Conserving moisture

• Rainwater harvesting

• Locally adopted crops and varieties

• Contingence planning

Rainwater management

Combination of practices

Vermicomposting

Mixed croppingPlanting on bunds

Soil productivity Management• Plants as nutrient mining systems• Soil is understood as strata to hold plants• Only available nutrients are measured• External nutrient application-no measure of

utilisation• Soil-chemical, biological and physical properties• Biomass application is also seen as external

nutrient application…so measures only the content

KPN

Ca SMg

Fe ClMnZn Cu

O HC

B Mo

Major and micro nutrients Micro Nutrients

Source Air Water Soil Soil

Carbon Hydrogen Nitrogen Manganese

Oxygen Phosphorus Molybdenum

Nitrogen Potash Copper

Calcium Boran

Magnesium Zinc

Sulfur Chlorine

Iron

Essential Nutrients of PlantsElement Chemical symbol Atomic Wt. Ionic forms absorbed by

plantsApproximate dry concentration

Macronutrients

Nitrogen N 14.01 NO3-, NH4

+ 4.0 %

Phosphorus P 30.98 PO43-, HPO4

2-, H2PO4- 0.5 %

Potassium K 39.10 K+ 4.0 %

Magnesium Mg 24.32 Mg2+ 0.5 %

Sulfur S 32.07 SO42- 0.5 %

Calcium Ca 40.08 Ca2+ 1.0 %

Micronutrients

Iron Fe 55.85 Fe2+, Fe3+ 200 ppm

Manganese Mn 54.94 Mn2+ 200 ppm

Zinc Zn 65.38 Zn2+ 30 ppm

Copper Cu 63.54 Cu2+ 10 ppm

Boron B 10.82 BO32-, B4O7

2- 60 ppm

Molybdenum Mo 95.95 MoO42- 2 ppm

Chlorine Cl 35.46 Cl- 3000 ppm

Essential But Not Applied

Carbon C 12.01 CO2 40 %

Hydrogen H 1.01 H2O 6 %

Oxygen O 16.00 O2, H2O 40 % Plant tissues also contain other elements (Na, Se, Co, Si, Rb, Sr, F, I) which are not needed for the normal growth and development

Liebig principle

Plant growth is influenced by a nutrient at lowest concentration as a denominator

Healthy crop

Good nutrient managementGood tilth

Improving soil biota

Good cropping patterns

Mulching

Plough across the slope

In sandy soils add tank silt to increase water holding capacity and fertility

Application of at least 10 tonnes of tank silt per acre once in 3 years increases soil productivity considerably

Water harvesting

Water Management

Modern agriculture: irrigation, drip, sprinkler

Sustainable Agriculture: focuses more on conserving soil moisture, increasing organic matter, mulching, cover crops, cropping patterns etc…

Rainwater conservation measures

Conservation of the entire rain water in the field itself

•3.19 lakh acres of 1.46 lakh SC/ST farmers 2009-10•10 lakh acres in 2010-11

Components include Trench, Conservation furrows, Farm Pond, compost pit , tank silt application. Rs. 48,000 per acre - MGNREGS

Glimpses of insitu water harvesting CMSA

Critical Stages of crop growth

• Paddy: tillering stage, flowering, milking• Maize/jowar: flowering, panicle initiation, milking• Groundnut: flowering, prop root stage, pod

formation• Cotton: flowering, boll formation• Soybean/redgram/greengram/blackgram:

flowering, grain formation• Sunflower: bud formation, flowering, grain

formation

Factors influencing soil fertility and moisture

Rainwater

Organic Matter

Soil depth

Soil Structure

Water flow Nutrient release

Soil depth

Groundwater Basic minerals

Minerals

Living beings

Soil Organic matter The soil organic matter has declined from about 1.43 and 1.21 %

in red and black soils in the 1950’s to about 0.80 to 0.86 percent respectively at present.

Soil organic matter performs Hydrological, Biological and Nutrient related functions, which are both interrelated and distinct.

The OM helps tide over dry spells and in reducing runoff. Soil moisture and organic matter is essential even for improving the efficiency of biofertilisers and chemical nutrients.

For better decomposition Maintain C:N ratio in the range of 30-40:1 Application of water regularly to maintain around 60% moisture

'Organic Matter is Possible

Biomass source Biomass per Year (kgs/ ac) Remarks

Gliricidia/ Cassia 3000 to 4000 30kgs/ plant – from 5th year of planting

Sunhemp sown on bunds/ borders

350 @1.3 kgs/ sqm. 50% of bund length of 280 m

Biomass yielding trees` 450 @150 kgs/ tree, two loppings

Weeds 200 - 300

Crop residues 500 - 1000

Legume inter-crop 500

T O T A L 4000 - 5000

Green manure (legumes) crops when integrated as intercrops, would add about 1.5 to 3 tons/ ha of fresh biomass in situ.

Studies have shown that legume intercrops can add 0.30 to 2.4 tons of leaf litter per ha even in a drought year; with 4.1 to 35.6 kg N per ha.

Gobar Parva

Gobar Parva

Gobar Parva

Aakulu tokke panduga – KK Tanda

Aakulu tokke panduga – KK Tanda

Micro organismsDecomposition by microorganisms releases NutrientsProtect plants from diseasesImproves soil structure

Macro organisms•Incorporate organic matter in soil•Makes capillary pores in the soil to increase water infiltration and air circualtion

In factoryIn roots

Nitrates to plants

‘P’ for Plants

• Applied water soluble ‘P’ is, on an average, used @ 12-9-6-3% from year of application

• Considerable (70%) part of applied ‘P’ is locked in the soil first as tricalcium phosphate (TCP) and finally as apatite

• in paddies, under heavy soils, considerable part of applied ‘P’ gets converted into apatite

• P in TCP is unavailable but can be used by plants in association with Mycorrhizae and to some extent by Phosphobacteria

Factors limiting P availability and uptake

• Amongst the nutrients, nitrogen is universally limiting and in most trials this aspect is given due attention.

• But more often, the widespread Zinc deficiency is ignored and it could as well be a limiting factor in showing response to applied P

• At lower levels or production, the native phosphorus itself may be adequate and thus no response to applied P

• Some elements may become toxic (e.g. Boron). Subsoil salinity could be another factor

• With temporary or transient water logging or wet regime, Fe3+ iron may be reduced to Fe2+ leading to possible precipitation of phosphates

• The organic acids released by the legumes (Pscidic acid from pigeonpea roots) would solubilise phosphates or chelate metal irons like Ca2+, Fe2+ liberating part of the bound phosphorus. The VAM fungi may also accentuate the availability of phosphorus.

• VAM and other fungal bodies associated with roots improve the availability of difficulty available phosphates

• Method of application is important in enhancing fertiliser P use efficiency. Placement, in association with ammonical nitrogen is very effective.

Level of P requirement

Crop group Critical level

of P (P2 O5)

Low Pastures, grasses, small grains, field corn, soybean, etc.

35

Moderate Cotton, sweet corn, tomato etc.

60

High Potato, onion etc. 90

Soil critical values for phosphorus for different groups of crops

Organic matter increases P availability in four ways.First, organic matter forms complexes with organic phosphate which increases phosphate uptake by plants.Second, organic anions can also displace sorbed phosphate.Third, humus coats aluminum and iron oxides, which reduces P sorption.Finally, organic matter is also a source of phosphorus through mineralization reactions.

Flooding the soil reduces P-sorption by increasing the solubility of phosphates that are bound to aluminum and iron oxides and amorphous minerals.

In natural forestsa fistful of soil contains600-800 bacteria3000 fungi which are miles longer10000 unicellular organisms20-30 nematodes

Living in soil, making soil fertile and avoiding disease causing organisms

Soil where chemical fertilisers are used

Organically managed soils

How to increase soil organic matter

Leaving crop residues in field

Using organic manure with and mulching with crop residues

Practicing good tillage

Composting

Green manure crops and Good cropping patterns

Other important resources

subabool

Calatropis Glyrecidia

Cassia

seethafal

Functional pool Turnover time (yrs)

Composition

Decomposable

Metabolic litter 0.1-0.5 Cellular contents, cellulose

Structural litter 0.3-2.1 Lignin, polyphenol

Soil organic matter

Mulching

Crop Choices

• Market demand• Soil and growing conditions

Crop duration Water requirement crops

One season (< 4 months

Low Greengram, blackgram, chickpea, kharif groundnut

Medium Jowar, maize, rabi groundnut,

More than one season (6-8 months)

More Cotton, chillies

Year or longer Very high Sugarcane, banana

Based on soil depth

• Shallow roots (60 cm): ragi, sama, korra, onion, cauliflower, cabbage, potato

• Medium deep roots (90 cm): groundnut, chillies, wheat, tobacco, castor

• Deep roots (120 cm): maize, sugarcane, jowar, bajra, safflower, soybean, tomato, carrot, cucumber

Crop Management in Rain-fed areas• Low water consuming crops• Perennials on conservation furrows including green leaf

manure plants.• 7 tiered crop canopy ( 36*36 model ) near farm pond.

Probiotics

PanchagavyaJeevamrutAmrutjal

Cow/BuffaloIndegenous/improved

WWW.CSA-INDIA.ORG

ramoo.csa@gmail.com

09000699702

040-27017735

www.agrariancrisis.in

www.krishi.tv