Technical Bulletin TB-1 Ag ricultural · Colorado State University, Southwestern Colorado Research...

Technical Bulletin TB-1

Ag ricultural

Experiment Station

College of Agricultural Sciences

Southwestern Colorado Research Center

Extension

The Feasibility of Cover Crops in Dryland

Cropping Systems in SW Colorado and SE Utah

Western SARE Research & Education Project SW15-008

2015-2017 Results

The Feasibility of Cover Crops in Dryland Cropping Systems in SW Colorado and SE Utah

Abdel F. Berrada1 and Courtney Roseberry2 Colorado State University, Southwestern Colorado Research Center AcknowledgmentsFunding for this project SW15-008 is provided by the Western Sustainable Agricultural Research and Education (SARE) program. We would like to thank the following project team members for their help and participation:

Don Andrews, NRCS, Monticello, UT Steve Barry, Farmer, Eastland, UT Jenny Beiermann, CSU Extension, Grand Junction, CO Ammon Boswell, NRCS, Monticello, UT Travis Custer, High Desert Conservation District, Cortez, CO Levi Garchar, Farmer, Dove Creek, CO Tom Hooten, CSU Extension, Montezuma County, CO Amber Johnson, NRCS, Monticello, UT John Lestina, NRCS, Dove Creek, CO Shay Lewis, Farmer, Monticello, UT Francine, Lheritier, NRCS, Grand Junction, CO David & Linda McCart, Farmers, Dove Creek, CO Blaine Nebeker, Farmer, Eastland, UT Vic Parslow, NRCS, Richfield, UT Aaron Waller, NRCS, Casper, WY Bill & Rhonda Waschke, Farmers, Dove Creek, CO Gus Westerman, CSU Extension, Dolores County, CO

Dr. Kathleen (Katie) Russell (CSU-Southwestern Colorado Research Center) and Dr.

Steven (Steve) Fonte (CSU-Soil & Crop Sciences) reviewed this publication.

Disclaimer: **Mention of a trademark or proprietary product does not constitute endorsement by the Colorado Agricultural Experiment Station.** Colorado State University does not discriminate on the basis of race, age, creed, color, religion, national origin or ancestry, sex, gender, disability, veteran status, genetic information, sexual orientation, gender identity or expression, or pregnancy. Colorado State University is an equal opportunity/equal access/affirmative action employer fully committed to achieving a diverse workforce and complies with all Federal and Colorado State laws, regulations, and executive orders regarding non-discrimination and affirmative action. The Office of Equal Opportunity is located in 101 Student Services.

1 Abdel Berrada, Project Principal Investigator, Senior Research Scientist & Manager 2 Courtney Roseberry, Former Project Coordinator & Field Technician, Research Associate I

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Table of Contents Acknowledgments ........................................................................................................................................ i Table of Contents ......................................................................................................................................... ii List of Tables ............................................................................................................................................... iv

List of Figures .............................................................................................................................................. v

Appendix B. Additional Figures .................................................................................................................. v

ABSTRACT .................................................................................................................................................. 1

INTRODUCTION ........................................................................................................................................ 2

LITERATURE REVIEW ............................................................................................................................. 2

PROJECT OBJECTIVES ............................................................................................................................. 6

MATERIALS AND METHODS .................................................................................................................. 6

1. Sites and experimental design: .......................................................................................................... 6

2. Field Management ............................................................................................................................ 7

3. Measurements ................................................................................................................................... 8

a. Climatic Data ................................................................................................................................ 8

b. Soil testing .................................................................................................................................... 9

c. Soil water content...................................................................................................................... 10

d. Soil water infiltration ................................................................................................................ 10

e. Vegetation sampling .................................................................................................................. 11

f. Cash crop yield and quality. ........................................................................................................ 12

g. Earthworm Surveys .................................................................................................................. 12

h. Economic analysis ..................................................................................................................... 12

2015-2017 RESULTS ................................................................................................................................. 13

1. Weather data ................................................................................................................................... 13

a. Precipitation: ............................................................................................................................. 13

b. Temperature: ............................................................................................................................. 14

2. Research Center Trials .................................................................................................................... 14

a. SWCRC #1 .................................................................................................................................. 14

i. Trial information ..................................................................................................................... 14

ii. Results ..................................................................................................................................... 16

1. Cover Crops ........................................................................................................................ 16

2. Winter Wheat ...................................................................................................................... 18

b. SWCRC #2 .................................................................................................................................. 19

i. Trial information (Table 15 & Table 16 in Appendix A, Figure 4 in Appendix B) ................ 19

ii. Results ..................................................................................................................................... 21

1. Cover Crops ........................................................................................................................ 21

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2. Winter Wheat ...................................................................................................................... 24

3. On-Farm Trials ................................................................................................................................ 26

a. Barry Middle (approx. 69 acres) .............................................................................................. 26

i. Test information (Table 22 in Appendix A) ........................................................................... 26

ii. Results ..................................................................................................................................... 27

1. Wheat yield (2015-2016) .................................................................................................... 27

2. Cover crops ......................................................................................................................... 27

3. Winter wheat (2017-2018) .................................................................................................. 29

b. Barry West half, SW Field (approx. 53 acres) ......................................................................... 30


ii. Results ..................................................................................................................................... 31

1. Cover crops ......................................................................................................................... 31

2. Winter Wheat ...................................................................................................................... 33

c. Barry East half, SW Field (approx. 53 acres) ........................................................................... 34


ii. Results ..................................................................................................................................... 35

1. Cover crops ......................................................................................................................... 35

2. Winter wheat (2017) ........................................................................................................... 37

d. Barry North (approx. 47 acres) ................................................................................................ 37


ii. Results ..................................................................................................................................... 40

1. Cover crops ......................................................................................................................... 40

2. Winter wheat ....................................................................................................................... 41

e. Crowley-Nebeker (approx. 29 acres) ....................................................................................... 41


ii. Results ..................................................................................................................................... 42

1. Cover crops ......................................................................................................................... 43

2. Cash Crops .......................................................................................................................... 44

f. Garchar (approx. 40 acres) ....................................................................................................... 45


ii. Results ..................................................................................................................................... 46

1. Cover Crops ........................................................................................................................ 46

2. Cash Crop ............................................................................................................................ 47

g. Lewis (approx. 46 acres)........................................................................................................... 47


ii. Results ..................................................................................................................................... 49

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1. Cover Crops ........................................................................................................................ 49

2. Cash Crop ............................................................................................................................ 50

h. Waschke (approx. 66 acres) ..................................................................................................... 51

i. Test information (Table 49 in Appendix A, Figure 12 in Appendix B) .................................. 51

1. Results ................................................................................................................................. 51

4. Soil Water Infiltration ..................................................................................................................... 51

CONCLUSIONS AND DISCUSSION ...................................................................................................... 53

Appendix A: Additional Tables ................................................................................................................. 57

List of Tables Table 1. Weather Station Descriptions ......................................................................................................... 9 Table 2. Parameters included in soil test analyses ...................................................................................... 10 Table 12. Soil test results at SWCRC #1 in the fall of 2015, 2016, and 2017 (Sample depth 6 inches) .... 16 Table 13. Plant biomass and canopy cover at SWCRC #1 on 6/8/2016 ..................................................... 17 Table 14. Soil moisture, infiltration rate, and wheat yield at SWCRC #1 .................................................. 19 Table 17. Cover Crop Mixes in SWCRC#2 ................................................................................................ 20 Table 18. Soil test results at SWCRC #2 prior to CCM planting in August 2016 (Sample depth 6 inches) ......................................................................................................................................................... 21 Table 19. Gravimetric soil moisture at SWCRC#2 ..................................................................................... 22 Table 20. Plant Biomass Production Summary at SWCRC #2 (Sample dates: 6/19/ 2017 & 6/20/2017) . 23 Table 21. Soil test results at SWCRC #2 in September 2017 (Sample depth 6 inches) ............................. 25 Table 23. Barry Middle March Soil Data (Sample date 3/17/2017, sample depth 6 inches) ...................... 26 Table 24. Gravimetric soil moisture by weight at Barry Middle ................................................................ 28 Table 25. Plant Biomass & Canopy Cover at Barry Middle (Sample date 6/16/2017) .............................. 29 Table 26. Barry Middle August Soil Data (Sample date 8/24/2017, sample depth 6 inches) ..................... 30 Table 28. Barry WSW March Soil Data (Sample date 3/17/2017, sample depth 6 inches) ........................ 31 Table 29. Gravimetric soil moisture by weight at Barry WSW .................................................................. 32 Table 30. Plant Biomass and Canopy Cover at Barry SW West Half (Sample date 6/16/2017) ................ 32 Table 31. Barry WSW August Soil Data (Sample date 8/24/2017, sampled depth 6 inches) .................... 33 Table 33. Barry SW East Half Soil Test Results Summary (Sample depth 6 inches) ................................ 34 Table 34. 2016 On-Farm Trial Gravimetric Soil Moisture Results ............................................................ 36 Table 35. Plant Data at Barry ESW in 2015 & 2016 .................................................................................. 36 Table 37. Barry North Soil Test Results Summary (Sample depth 6 inches) ............................................. 39 Table 38. Plant Data at Barry North ........................................................................................................... 40 Table 40. Crowley Soil Test Result Summaries (Sample depth 6 inches) .................................................. 42 Table 41. Plant Biomass and Canopy Cover at Crowley (Sample date 6/15/2017) .................................... 44 Table 42. Safflower yield at Crowley’s in 2016 ......................................................................................... 44 Table 44. Garchar Soil Test Results (Sample depth 6 inches) .................................................................... 46 Table 45. Garchar Plant Data for 2016 ....................................................................................................... 48 Table 47. Lewis Soil Results Data (Sample depth 6 inches) ...................................................................... 49 Table 48. Lewis Plant Biomass & Canopy Cover (Sample date 5/15/2017) .............................................. 50 Table 50. Soil infiltration rates in 2016 and 2017 ....................................................................................... 52 Table 3. 2015 Monthly Precipitation in Yellow Jacket, Dove Creek, Eastland, and Monticello ............... 58 Table 4. Long-term precipitation averages in Yellow Jacket, Dove Creek, Eastland, and Monticello ...... 59 Table 5. 2016 Monthly Precipitation in Yellow Jacket, Dove Creek, Eastland, and Monticello ............... 60 Table 6. 2017 Monthly Precipitation in Yellow Jacket, Dove Creek, Eastland, and Monticello ............... 61 Table 7. Monthly Temperature at the CoAgmet Station in Yellow Jacket, CO ......................................... 62

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Table 8. Monthly Temperature at the CoAgmet Station in Dove Creek, CO ............................................. 63 Table 9. Monthly Temperature at the SCAN Station in Eastland, UT........................................................ 64 Table 10. Monthly Temperatures at GHCN station in Monticello, UT ...................................................... 65 Table 11. SWCRC #1 Trial Information (Soil type: Wetherill Loam, Sharps-Cahona) ............................. 66 Table 15. SWCRC #2 Trial Information – Conventional Tillage (Soil Type: Wetherill Loam, Sharps-Cahona) ....................................................................................................................................................... 67 Table 16. SWCRC #2 Trial Information – No Till (Wetherill Loam, Sharps-Cahona) .............................. 69 Table 22. Barry Middle Trial Information (Soil type: Cahona Series) ....................................................... 70 Table 27. Barry WSW Trial Information (Soil type: Cahona Series) ......................................................... 72 Table 32. Barry ESW Trial Information (Soil type: Cahona Series) .......................................................... 73 Table 36. Barry North Trail Information (Soil type: Monticello Series) .................................................... 74 Table 39. Crowley-Nebeker Trial Information (Soil type: Monticello series) ........................................... 75 Table 43. Garchar Trial Information (Soil type: Granath Series) ............................................................... 76 Table 46. Lewis Trial Information (Soil type: Monticello Series) .............................................................. 77 Table 49. Waschke Trial Information (Soil type: Cahona Series) .............................................................. 79 List of Figures Figure 1. Farm Trial Locations ..................................................................................................................... 7 Figure 2. Weather Station Locations........................................................................................................... 14 Appendix B. Additional Figures Figure 3. SWCRC #1 Plot layout ................................................................................................................ 81 Figure 4. SWCRC #2 Plot Layout .............................................................................................................. 82 Figure 5. Barry Middle Field Layout .......................................................................................................... 83 Figure 6. Barry West half, SW Field Layout .............................................................................................. 84 Figure 7. Barry East half, SW Field Layout ............................................................................................... 85 Figure 8. Barry North Field Layout ........................................................................................................... 86 Figure 9. Crowley-Nebeker Field Layout ................................................................................................... 87 Figure 10. Garchar Field Layout ................................................................................................................. 88 Figure 11. Lewis Farms Field Layout ......................................................................................................... 89 Figure 12. Waschke Field Layout ............................................................................................................... 90

ABSTRACT This project stems from the need to protect our soil and water resources, reduce our dependence on chemical inputs, improve soil health and fertility, and increase dependable production of healthy foods. We hope to achieve some of these benefits by incorporating cover crops in dryland cropping systems and by doing so, enhance their sustainability in the unique and challenging environment of SW Colorado and SE Utah. The project objectives are to (1) test the growth and performance of different cover crop species/mixtures across distinct site and management contexts; (2) assess the impacts of cover crops on soil fertility, soil moisture, cash crop yields, and overall farm profit; and (3) disseminate project results and contribute to improved soil health management in the region. To accomplish these objectives, we established two field trials at the Southwest Colorado Research Center (SWCRC) and eight research and demonstration trials on farmers’ fields. These trials encompass two crop rotations (winter wheat-fallow and winter wheat-safflower-fallow), two tillage regimes (conventional tillage and no-till), as well as conventional and organic crop production systems. To date, 19 summer or early fall-planted and five spring-planted cover crop mixtures have been tested. Even though it is too early to draw conclusions as to the feasibility of cover crops in dryland cropping systems in the project area, some key preliminary findings are:

1. Late summer or early fall-planted cover crops produced considerably more biomass than the spring-planted cover crops. For example, plant biomass of spring-planted mixtures averaged 713 lbs/ac in 2017, while fall-planted mixtures exceeded 4000 lbs/ac in 2016 at the SWCRC. We also found that if cover crops are planted too early after wheat harvest and before adequate moisture is available then volunteer wheat tends to dominate plant canopy and biomass.

2. Some species performed poorly (e.g. teff, flax, sunn hemp, balansa clover) and the notion that the more species (i.e., higher diversity) in the mix, the better, may not hold true in the project area. We also note that climate in the region (semi-arid with short growing season), seed cost, and proper management (i.e., planting date, seeding depth, inoculation) are all key considerations for developing high performance cover crop mixtures.

3. The results from one experiment at the SWCRC showed a 27% yield penalty for wheat following cover crops vs. fallow, and that this is likely due to temporary immobilization of soil nitrogen and reduced soil moisture at planting. The yield penalties were lower (19 & 22%) for two on-farm trials for which we have results. No fertilizer was applied to the wheat and this will be reconsidered moving forward. While inputs costs were higher for the cover crop treatments, we feel that continued management refinements will help to reduce costs.

Project concepts and highlights have been presented at multiple events including: three field tours, one field day, six workshops, two growers’ meetings, two research center conferences, and two ASA-CSSA-SSSA annual meetings. Many of these presentations, along with project announcements, interviews, and useful links are available on the project website at http://drylandcovercrops.agsci.colostate.edu. Attendance to the outreach events has been generally good (approximately 15 to 60 participants/event). Moreover, the attendees appear to have gained knowledge on cover crops, soil health, and management practices. These and other

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indicators bode well for the adoption of cover crops and other soil health improvement practices in the region.

INTRODUCTION Incorporating cover crops in crop rotations may offer a means to enhance dryland farming in SW Colorado and SE Utah. The project area has a unique environment, which makes dryland farming a challenge. The growing season is relatively short (90 to 120 days) and natural precipitation (from rain and snow) averages 10 to 16 in., with a lot of variation from year to year and within the year. Consequently, crop yields are generally low (e.g., around 20-30 bu/acre for winter wheat and 200 to 400 lbs/acre for dry bean). Winter wheat-fallow and winter wheat-dry bean are the most common crop rotations, followed by winter wheat-safflower or sunflower-fallow. During the fallow period, the soil is generally disked and/or plowed in the fall then worked several times in the spring with a field cultivator to control weeds and prepare the seedbed for the next crop. This practice of maintaining a clean fallow exposes the soil to erosion and the loss of topsoil and with it the loss of nutrients and organic matter. It also leads to water loss via evaporation. Organic matter in the project area is typically around 1% in the top foot of soil. Soil erosion is exacerbated by the rolling terrain and the tendency of the soil to crust after a rain event. The number of acres in minimum or no-till is comparatively low with modest gains in recent years. There has also been an increase in organic grain (wheat, safflower, and dry bean) production due to higher prices, which makes sense since most dryland farmers in the project area use little or no fertilizer or pesticides to begin with. Some drawbacks of organic farming in its present form include a reliance on tillage to control weeds and the lack of economical options to add nutrients to the soil. Incorporating cover crops in the rotation could lead to fewer tillage operations by suppressing weeds and would provide other benefits, such as erosion control, N fixation, and increased carbon and nutrient cycling. Local familiarity with cover crops and soil health is gaining momentum, however most of the research and success stories come from humid regions and from irrigated agriculture. Research-based information relating to cover crop use in dryland farming in semi-arid environments is scarce or inconclusive, primarily because of uncertainty surrounding the trade-off between potential soil quality contributions and soil moisture use by cover crops. Such information was lacking locally, which prompted a group of farmers, conservation districts, USDA-NRCS, and Colorado State University (CSU) personnel to brainstorm ways to study the potential benefits of cover crops in SW Colorado and the adjacent farming area of SE Utah. This led to the current project entitled “The Feasibility of Cover Crops in Dryland Cropping Systems in SW Colorado and SE Utah”. The overall goal of this project is to determine if and how cover crops grown during the fallow period between two cash crops can enhance the sustainability of dryland farming in SW Colorado and SE Utah. Specific objectives are listed under “Project Objectives”.

LITERATURE REVIEW Cover crops can cut fertilizer costs, reduce the need for pesticides, help protect the soil against erosion, and improve crop yield, among other things (Clark, 2012). Cover crop species and mixes should be selected based on need, location, and expected results. For example, in the

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Colorado Plateau with its low organic matter soils and low-input farming, including legumes in the mix is a must if the goal is to improve soil fertility. Legumes can contribute from 15 to 200 lb N/ac to the subsequent crop, with typical values of 50 to 100 lb/ac (Clark, 2012). In a review of the literature, Snapp et al. (2005) stated that “legume cover crops are the most reliable means to enhance cash crop yields compared with fallows or other cover crop species”. Cereal cover crops can produce large amounts of biomass and thus help suppress weeds and build soil organic matter. Rye is a good choice for winter niches (Snapp et al, 2005). However, cover crop mixtures are often more productive than sole crops. In Nebraska, the land equivalent ratios (LERs) of four cover crop mixtures were >1.0, indicating mixtures were more productive than the individual components grown as sole crops. Partial LERs of species in the mustard family were consistently greater than those in the legume family. Sole crops in the mustard family were twice as productive as sole crops in the legume family over a 2-yr period (Wortman et al., 2012a). Rapid canopy development and allelopathy from decomposing residue contribute to weed suppression by Brassicas (Lawley et al., 2012). Cover crops reduce soil erosion, which is a major concern in the Colorado Plateau. Painter et al. (2007) found that snow cover duration in the San Juan Mountains was shortened by 18 to 35 days due to dust. Blanco-Canqui et al. (2013) concluded that cover crops grown in no-till winter wheat-fallow rotations, during the fallow period, can reduce soil erosion in the semiarid central Great Plains. They compared winter triticale, winter lentil, spring lentil, spring pea, and spring triticale to wheat–fallow and continuous wheat under no-till management in Garden City, KS. Spring triticale and spring lentil increased soil aggregate size distribution, while spring lentil reduced the wind erodible fraction by 1.6 times. Cover crops also increased wet aggregate stability and reduced runoff loss of sediment, total P, and NO3–N. After 5 yr, winter and spring triticale increased soil organic carbon (SOC) by 1.25 tons/acre and spring lentil increased SOC pool by 1.07 tons/acre in the 0- to 3.0-in depth compared with fallow. However, nine months after termination, cover crops had no effects on soil properties, suggesting that cover crop benefits are short lived in this climate. Haying triticale for 5 years did not influence soil properties compared with no haying. A major concern in semi-arid environments is water use by cover crops, specifically, how much water is available for the next crop after cover crops are terminated. Where precipitation is limited, cover crops often reduce yields of subsequent crops due to soil water depletion (Unger and Vigil, 1998). In a semi-arid region of northwest China, Zhang et al. (2016) found that substituting a leguminous green manure to bare fallow increased wheat yield and water use efficiency in years with normal or above normal precipitation. The reverse was true in drier years. Similarly, in a long-term study in SW Kansas, growing a crop during the fallow period had little impact on wheat yield in wet years (2008-2010) but significantly reduced wheat yield in dry years (2011-2014). The effect was less pronounced if the cover or hay crop was terminated early (June 1) than if the crop was grown for grain (termination in early July). Overall, cover crops did not improve wheat or grain sorghum yields compared to fallow. Cover crops always resulted in less profit than fallow, while annual forages often increased profit compared to fallow (Holman et al., 2016). In a 5-yr study at Akron, CO (1994-1999), Austrian winter pea, spring field pea, black lentil, and hairy vetch were planted in early April and terminated at 2-wk intervals, starting in early June, to determine their effects on soil water content at wheat planting and subsequent wheat yield (Nielsen et al., 2005). Soil water at wheat planting decreased by 2.2 in (55 mm) when legumes

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were terminated early and by 4.1 in (104 mm) when legumes were terminated late, compared with soil water in conventionally tilled (CT) fallow plots. In general, there were no differences in soil water content between the legumes. Wheat yield increased in a linear fashion with the available soil water at planting but there were variations from year to year depending on evaporative demand and precipitation in April, May, and June. The authors concluded that “the cost in water use by the legume and subsequent decrease in wheat yield may be too great to justify the use of legumes as fallow cover crops in wheat-fallow systems in the semi-arid environment of the central Great Plains.” In a more recent publication, Nielsen and Vigil (2017) found that replacing fallow with pea in a Wheat-Corn-Proso millet-Fallow (WCMF) rotation resulted in a significant reduction of available water at planting, water use and yield of wheat and corn but had little effect on the same factors in millet. The total grain production of WCMF and Wheat-Corn-Millet-Pea (WCMP) was similar but the net income of WCMP was 32% lower than that of WCMF. Intensifying WCMF by replacing fallow with pea would be recommended only if the costs of pea seeds and N fertilization of the wheat crop can be reduced. In a 3-yr study at Akron, CO and Sidney, NE, wheat yield was 17% lower when fallow was replaced with triticale in a Wheat-Corn-Fallow (WCF) rotation, primarily due to lower water content at wheat planting (Nielsen et al, 2017a). Corn yield was not affected by substituting triticale to fallow. Overall, the cropping system’s net return was 17% greater for WCT than for WCF. Incorporation of a forage crop in winter wheat-based rotations in the CENTRAL Great Plains can lessen the effects of climate variability on dryland cropping and enhance their profitability and sustainability (Nielsen et al, 2016b). A common recommendation is to include multiple species in cover crop mixtures to enhance their synergetic effects on soil health and productivity. Although species diversification (e.g., grasses, legumes, brassicas, etc.) may be important to accomplish specific objectives, research results from the Central Great Plains do not show an advantage of multiple species over single species cover crop mixtures. In a 2-yr study (2012 and 2013) at Akron, CO and Sidney, NE, there were no significant differences in soil water content or growing season water use between a single species cover crop and a 10-species cover crop mixture, with or without irrigation (Nielsen et al, 2015a). Winter wheat yield decreased by 10% on average following flax, oat, pea, rapeseed or a 10-species cover crop mixture, compared to the fallow treatment with Proso millet residue (Nielsen et al, 2015b). The wheat yield reduction was greater under drier conditions. The cover crop mixture did not produce more biomass or show greater water use efficiency than the single-species. Moreover, residue cover was not generally greater from the mixture than from single-species plantings (Nielsen et al., 2015c). The authors concluded that the expense associated with a multi-species cover crop mixture compared to a single species was not justified, unless the mixture provides better forage quality for grazing or haying. However, the long-term effects of single vs. multi-species cover crops on soil health or quality were not addressed. Cover crop residues may increase water availability by increasing infiltration and reducing evaporation losses (Clark, 2012). Maintaining crop residues on the soil surface will enhance water conservation and crop yield and provide some of the same benefits derived from cover cropping. In Montana, wheat following legume green manures (LGMs) produced less grain than wheat following no-till fallow (O’Dea and Miller, 2010). The decline in wheat yield was attributed to LGMs temporarily limiting soil N available to the wheat crop. In cover crop

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mixtures (CCM) that include no N-fixing crops, some amount of starter N may be required to obtain balanced CCM biomass proportions (Miller, 2012). Termination of cover crops with a sweep plow undercutter increased soil moisture content by as much as 0.18 gal/ft3 and increased soil nitrate N (0–8 in.) by 1.0 and 1.8 ppm in 2010 and 2011, respectively, compared to disk incorporation (Wortman et al., 2012b). Other methods of terminating cover crops include herbicide use and breaking the stems with a roller-crimper and mowing or chopping the green matter (Clark, 2012). Spraying cover crops with a non-selective herbicide is the method of choice in minimum- and no-till systems. Roller-crimpers work best with tall-growing cover crops and when rolling is delayed until flowering or later. Mowing or chopping is another alternative to herbicide use but it is more energy intensive. Andy Clark (Ed.). 2012. Managing Cover Crops Profitably. Sustainable Agriculture Research and

Education Handbook Series Book 9, 3rd Edition.

Blanco-Canqui, H., J.D. Holman, J. Tatarko, and T.M. Shaver. 2013. Replacing Fallow with Cover Crops in a Semiarid Soil: Effects on Soil Properties. Soil Sci. Soc. Am. J. 77:1026–1034.

O’Dea, J., and P. Miller. 2010. Investigating the Legume Green Fallow Alternative on North-Central Montana No-Till Operations. WSARE Project GW10-032, 2010 Final Report.

Holman, J. D., T. Roberts, and S. Maxwell. 2016. Fallow replacement crop (cover crops, annual forages, and short-season grain crops) effects on wheat and grain sorghum yields. Kansas Agricultural Experiment Station Research Reports: Vol. 2: Iss. 7.

Lawley, Y.E., J.R. Teasdale, and R.R. Weil. 2012. The Mechanism for Weed Suppression by a Forage Radish Cover Crop. Agron. J. 104:205–214.

Nielsen, D.C., J.J. Miceli-Garcia, and D.J. Lyon. 2017. Replacing fallow with forage triticale in dryland crop rotations increases profitability. Field Crops Research 203:227-237.

Nielsen, D.C., and M.F. Vigil. 2017. Intensifying a semi-arid dryland crop rotation by replacing fallow with pea. Agricultural Water Management 186:127-138.

Nielsen, D.C., D.J. Lyon, G.W. Hergert, R.K. Higgins, F.J. Calderón, and M.F. Vigil. 2015a. Cover crop mixtures do not use water differently than single-species plantings. Agron. J. 107:1025–1038.

Nielsen, D.C., D.J. Lyon, R.K. Higgins, G.W. Hergert, J.D. Holman, and M.F. Vigil. 2015b. Cover crop effect on subsequent wheat yield in the Central Great Plains. Agron. J. 108(1):243-256.

Nielsen, D.C., D.J. Lyon, G.W. Hergert, R. K. Higgins, and J.D. Holman. 2015c. Cover crop biomass production and water use in the Central Great Plains. Agron. J. 107:2047–2058.

Nielsen, D.C., and M.F. Vigil. 2005. Legume green fallow effect on soil water content at wheat planting and wheat yield. Agron. J. 97:684–689.

Painter, T.H., A.P. Barrett, C.C. Landry, J.C. Neff, M.P. Cassidy, C.R. Lawrence, K.E. McBride, and G.L. Farmer. 2007. Impact of disturbed desert soils on duration of mountain snow cover. Geophysical Research Letters 34 (12).

Miller, P. 2012. Using cover crop mixtures to improve soil health in low rainfall areas of the northern plains. WSARE 2012 Annual Report Project SW11-099.

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Snapp, S.S., S.M. Swinton, R. Labarta, D. Mutch, J.R. Black, R. Leep, J. Nyiraneza, and K. O’Neil. 2005. Evaluating Cover Crops for Benefits, Costs and Performance within Cropping System Niches. Agron. J. 97:322–332.

Unger, P.W., and M.F. Vigil. 1998. Cover crop effects on soil water relationships. J. Soil Water Conserv. 53:200–207.

Wortman, S.E., C.A. Francis, and J.L. Lindquist. 2012a. Cover crop mixtures for the western Corn Belt: Opportunities for increased productivity and stability. Agron. J. 104:699–705.

Wortman, S.E., C.A. Francis, M.L. Bernards, R.A. Drijber, and J.L. Lindquist. 2012b. Optimizing Cover Crop Benefits with Diverse Mixtures and an Alternative Termination Method. Agron. J. 104:1425–1435.

Zhang, D., Yao, P., Na, Z., Cao, W., Zhang, S., Li, Y., and Y. Gao. 2016. Soil Water Balance and Water Use Efficiency of Dryland Wheat in Different Precipitation Years in Response to Green Manure Approach (https://www.nature.com/articles/srep26856, verified on March 13, 2018).

PROJECT OBJECTIVES 1. Determine the agronomic feasibility of cover crops in dryland cropping systems in SW

Colorado and SE Utah. The effects of cover crops on soil quality and health and on the cash crop are assessed. Measurements include cover crop biomass and percent cover, soil water content, soil infiltration rate, soil nutrient availability, soil microbial mass, and cash crop yield and quality.

2. Assess the economic feasibility of cover crops in dryland cropping systems. Partial budget analysis is conducted to track changes in revenue that result from the operational and input costs associated with planting cover crops. Analyses include measuring return on investment following cover crops, accounting for changes to yield or quality of cash crops to determine where a cover crop strategy produces a profit or loss to the operator. Indirect costs and benefits of cover crop management were documented.

3. Educate farmers and others about the potential benefits of cover crops and disseminate project results via:

i. The project website ii. Yearly field tours and workshops

iii. Factsheets, CSU/AES Technical Bulletins, and refereed journal articles iv. Presentations at growers and professional meetings, conferences, workshops, and

other relevant events in Colorado and Utah. 4. Gauge the project’s impact by how well the outreach events are attended, feedback from

these events, and changes in the number of acres planted to cover crops in the project area. USDA-NRCS continues to track the number of applications for cover crop grant assistance, and is assisting with long term monitoring of cover crop adoption.

MATERIALS AND METHODS 1. Sites and experimental design:

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Field trials were established at the Southwestern Colorado Research Center (SWCRC) in Yellow Jacket, Colorado, and on five farms in Southwestern Colorado and Southeastern Utah. The farms are located near Eastland, Utah (Pearson Point and Horsehead Point); Monticello, Utah; and in Dolores County, Colorado (Figure 1). All the trials were conducted on fields that have been historically farmed in a dryland, annual cropping system. At the on-farm trials, cover crops were planted in either a large block or in large strips with at least one strip of fallow for comparison. The trials at the SWCRC were established on smaller strips (20 ft. by 200 ft. in SWCRC trial #1 and 12 ft. by 100 ft. in SWCRC trial #2) with three replications. Approximate acreages, management, cropping systems, and general cover crop information for each field are listed under Results. Field maps are included in Appendix.

Figure 1. Farm Trial Locations

2. Field Management The staff at the Southwestern Colorado Research Center managed the two trials at Yellow Jacket. Each of the on-farm trials were managed by the farm owner or operator. Each farm owner/operator planted and terminated cover crops, managed weeds (via tillage or herbicide), prepared the fields for planting, and planted and harvested the cash

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crops. Research center staff assisted the farm owners/operators with specific tasks, such as purchasing/ordering cover crop seed, field design layout/marking, and hand sampling cash crops for yield and quality data. The cover species and mixtures are originally proposed by the USDA-NRCS District Conservationist in the county where the field is located and finalized after consultation with the farm owner/operator and the project team (e.g., project PI and project coordinator). Cultural practices for the fields managed under Conventional Tillage (CT) are typical of those used by dryland farmers in the project area. CT management relies heavily on tillage to control weeds/volunteer crops and prepare the field for planting. In at least one field (e.g., Garchar), no moldboard plowing was done. CT with no plowing or soil inversion is referred to as minimum-, mulch-, or reduced-till (RT). In both CT and RT, herbicide is used in addition to tillage to control weeds and volunteer crops. However, in organic systems (e.g., Crowley and Waschke) tillage is used solely to control weeds/volunteer crops. Some of the fields (e.g. Barry & SWCRC#1) were managed using No-Till (NT), which relies solely on herbicides to control weeds/volunteer crops. NT systems require special seed drills to plant into untilled soil and crop residue. Barry’s farm was 100% NT, while Crowley’s was partially organic, partially NT, and partially CT. Detailed management practices at each test site are listed in Results and in Appendix A.

3. Measurements a. Climatic Data: Precipitation and temperature data were collected and analyzed from

seven sources in the area: CoAgMet stations in Yellow Jacket, CO and Dove Creek, CO; CoCoRahs stations in Yellow Jacket, CO and Dolores County, CO; GHCN stations on Cedar Point, UT and in Monticello, UT; and a NRCS SCAN station in Eastland, UT (Table 1). The CoAgMet (Colorado Agricultural Meteorological Network) and NRCS SCAN (Soil Climate & Analysis Network) stations are fully automated stations with non-heated precipitation collection cups, while the CoCoRahs (Community Collaborative Rain, hail, snow) and GHCN (Global Historic Climatology Network) stations have rain/snow gauges that are manually emptied daily. Automated stations in the area tend to under report the amount of precipitation received during the winter months, likely due to cold air temperatures that prevent snow captured in the precipitation collection cups from melting. Annual precipitation and temperature data was downloaded from automated stations closest to the participating farms, for 2015, 2016, and 2017. Long-term precipitation and temperature data was retrieved from NOAA (National Oceanic and Atmospheric Administration) 30-year Normals data (1981-2010) and 10-year NRCS data (2007-2017). NOAA 30-year Normals data was used for Dove Creek, CO, Yellow Jacket, CO, and Monticello, UT, while NRCS 10-year average data was used for Eastland, UT.

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Table 1. Weather Station Descriptions

Station Name Station ID

Supporting Organization

Nearest Town

Latitude, Longitude

Measure Method

Associated Farm

Dolores Co. CO-DR-3 CoCoRaHS Dove

Creek, CO 37.6009, -108.9951 Manual Comparison

Purposes

Dove Creek DVCO1 CSU CoAgMet

Dove Creek, CO

37.7265, -108.954 Automated Garchar,

Waschke

Eastland 2130 NRCS-SCAN Eastland, UT

37.778533, -109.171927 Automated Barry,

Crowley Monticello 2E, UT US

USC00425805

NOAA GHCN

Monticello, UT

37.87361, -109.3075 Manual Lewis

Farms

Yellow Jacket YJK01 CSU CoAgMet

Yellow Jacket, CO

37.5289, -108.724 Automated SWCRC

Yellow Jacket CO-MZ-55 CoCoRaHS Yellow

Jacket, CO 37.544296, -108.739436 Manual Comparison

Purposes

b. Soil testing: Soil samples were analyzed through a variety of tests, to determine soil fertility and soil health as the project progressed (Table 2). Soil samples were taken using a soil probe at a depth of 0 to 6 inches. Initial baseline soil samples were collected as a composite of each field. Subsequent soil samples were taken as a composite of each treatment (cover crops vs. fallow) at each on-farm site, so that results from each treatment could be compared at each site. Soil samples at the research center were taken in each treatment and replication for statistical analysis. The soil tests that were chosen are the traditional soil test analysis (Traditional), Haney test or soil health test (Haney), Phospholipid Fatty Acid (PLFA) analysis, and the Cornell Assessment of Soil Health (CASH) test. CASH was later dropped because it was concluded that it did not provide a meaningful assessment of soil condition in our arid to semi-arid environment. Soil samples are sent to WARD LABORATORIES in Kearney, NE for the Traditional, Haney, and PLFA analyses. General information on nutrient management and information on the soil testing methodologies used by Ward Laboratories can be found at https://www.wardlab.com/download/WardGuide.pdf (Verfied on March 13, 2018). Information on Haney and PLFA is also posted on the lab’s website at: https://www.wardlab.com/. According to Dr. Ward, the Haney soil health test is designed to mimic “nature’s approach to soil nutrient availability as best we can in the lab”. Concerns with Haney include:

• “Soil Health Scores currently have high random variability (associated with test methodology). Therefore, it is unrealistic to regard the current Soil Health Score as a reliable indicator of real change in measured parameters in a field over time.

• Estimated nitrogen fertilizer savings reported with the Haney soil test data by some laboratories are not considered reliable. These projected fertilizer savings are strongly related to the highly variable soil respiration rate measured in the laboratory. The "N fertilizer savings" estimates provided with Haney test data have not been extensively validated in field trials in the

https://www.wardlab.com/download/WardGuide.pdf

https://www.wardlab.com/

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Western Region.” (http://landresources.montana.edu/soilfertility/documents/PDF/reports/NutDigSu2015.pdf)

To be fair, we have not searched the literature to verify the validity of these concerns or if they have been rebuked or addressed.

Table 2. Parameters included in soil test analyses

Test Test Parameters

Traditional pH, Phosphorus, Potassium, Calcium, Magnesium, Sodium, Sum of Cations, FIA Nitrate

Haney pH, Soil Organic Matter, Nitrogen, Phosphorus Pentoxide, Potassium Oxide, Solvita CO2 burst, Organic C:N, Nutrient Value, Nitrogen savings, Soil Health Calculation.

PLFA Total microbial biomass, % Bacteria, % Fungi, % Protozoa, % Undifferentiated, Microbial Diversity Index

CASH

Available Water Capacity, Surface Hardness, Subsurface Hardness, Aggregate Stability, Soil Organic Matter, ACE Soil Protein Index, Soil Respiration, Active Carbon, pH, Extractable Phosphorus, Extractable Potassium, Magnesium, Iron, Manganese, Zinc.

In the fall of 2015, composite soil samples were taken from all fields for the Traditional NPK, Haney, and PLFA tests, to serve as a baseline. From 2016 through 2017, Traditional NPK and Haney soil samples were taken before cover crop planting and before cash crop planting at all sites. PLFA soil samples were originally taken at the same time as the Traditional NPK and Haney, however the sampling time was changed in the spring of 2017, so that PLFA samples were taken at all sites in May 2017 and August/September 2017. The change was implemented to ensure that soil samples were taken at a time when conditions (e.g., soil moisture and temperature) may be optimal for microbial activity. In 2016, CASH soil samples were taken before cover crop planting or before cash crop planting. No CASH soil samples were taken in 2017.

c. Soil water content: Soil samples were taken at the on-farm sites with a hand auger before cover crop planting and before cash crop planting, at one-foot increments, down to 2 ft., depending on soil condition. In some instances, the soil was too dry to take samples. Soil samples were taken at the Research Center trials with a tractor-mounted Giddings probe before cover crop planting and before cash crop planting, at one-foot increments, down to 4 ft., depending on soil condition. Soil samples were taken in the cover crop and fallow treatments at all the trials. The samples were weighed, dried for 48 hours at 105° C in a forced air convection oven, and re-weighed to determine their water content.

d. Soil water infiltration: Soil infiltration rates for all sites were determined by using a Cornell Sprinkle Infiltrometer (Ogden et al., 1997)3. The infiltrometer was calibrated

3 Ogden, C.B., H. M. Van Es, and R. R. Schindelbeck. 1997. Miniature Rain Simulator for Field Measurement of Soil Infiltration. Soil Science Society of America Journal 61 (4): 1041-1043.

http://landresources.montana.edu/soilfertility/documents/PDF/reports/NutDigSu2015.pdf

http://landresources.montana.edu/soilfertility/documents/PDF/reports/NutDigSu2015.pdf

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at each site to provide a rainfall rate of approximately 0.5 cm/min. The infiltrometer was operated at a constant rainfall rate until the runoff rate reached a steady state (typically 45 minutes to one hour). The infiltration rate is calculated as the difference between the rainfall rate and the runoff rate, both of which can be measured in the field to allow for the detection of the infiltration steady state in the field. A baseline infiltration rate was calculated for each site in mid-September of 2015. In August and September of 2016, the infiltrometer was used at each treatment (cover crop and fallow) at all on-farm trials. At the first research center trial (SWCRC #1), the infiltrometer was used at each treatment in the first and second replications, prior to planting hard red winter wheat. At the second research center trial (SWCRC #2), the infiltrometer was used in the control (fallow) plots in the No-Till and Conventional Till second block (replication), to serve as baseline data (i.e. prior to planting cover crops). Additionally, the infiltrometer was used at two permanent pasture fields, to serve as a reference for infiltration in a non-cropland system (permanent dryland pasture and permanent dryland CRP). In 2017, the infiltrometer was used at all sites after a cover crop was planted and before field preparation/tillage or a cash crop was planted, depending upon field management. The adjustment in timing was needed to accommodate different field conditions (i.e. avoid tillage, avoid soil disturbance from seed drills, etc.) so that any differences in infiltration rates between treatments was less impacted by field condition.

e. Vegetation sampling: The Line-Point Intercept method4 was used to calculate canopy cover and ground cover within the cover crop treatments at all sites, prior to cover crop termination. A 50-meter tape (transect) was stretched perpendicular to the planted rows of cover crop and at each one-meter mark, a “hit” or a “miss” was recorded for plant canopy cover, plant basal cover, and ground cover. At each “hit” the cover type was recorded (cover crop, noxious weed, stubble, bare ground, etc.). In order to calculate % canopy cover and ground cover by type, the total hits for each type of cover was multiplied by 2. Biomass was determined by clipping plant matter in a specified area within the cover crop treatments at all sites, prior to cover crop termination. In fields with close drilled rows (rows less than 10 inches apart), the clipped area was determined via a 1.24 ft. radius, range hoop. The range hoop was placed at the beginning of the Line-Point Intercept transect, and the vegetation was clipped from the area of the range hoop, and stored in a paper bag. In fields with planted rows further apart than 10 inches, a row of the cover crop was clipped at a length determined by the formula 10.8 ÷ (row spacing in inches ÷ 12) = clipped length in feet, and stored in a paper bag. In 2017, the cover crop species present in each bag were separated and weighed separately. Plant matter was then dried at 60° C for 24 hours, and weighed again. The drying temperature and duration is adequate, since the plant material is fairly (air) dry when it is put in the oven. The dried weight in grams of plant matter collected using the

The user manual for the Cornell Sprinkle Infitrometer can be accessed at: https://cpb-us-east-1-juc1ugur1qwqqqo4.stackpathdns.com/blogs.cornell.edu/dist/f/5772/files/2015/11/Cornell-Sprinkle-Infiltrometer-manual-1xf0snz.pdf 4 Pp. 78-85 in “Sampling Vegetation Attributes”, Interagency Technical Reference 1734.4. Revised in 1999. Bureau of Land Reclamation, Denver, CO.

https://cpb-us-east-1-juc1ugur1qwqqqo4.stackpathdns.com/blogs.cornell.edu/dist/f/5772/files/2015/11/Cornell-Sprinkle-Infiltrometer-manual-1xf0snz.pdf



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range hoop method was multiplied by 20. It was then converted to lbs and multiplied by 1000, to get plant matter in lbs/acre.

f. Cash crop yield and quality: At the research center, wheat yield was determined by harvesting one (SWCRC #2) or two (SWCRC #1) strips in each plot with the Hege plot combine. Wheat from each strip was cleaned, weighed, and tested for moisture and density. A subsample was sent to a private laboratory to determine grain protein content. The same measurements were obtained from farmers’ fields by hand-harvesting and threshing all the wheat heads in 1.0 sq. m. sampling areas. The number of sampling areas was determined based on the size of the strip (fallow or cover crop treatment) on which wheat was grown. In one trial (Waschke), all the data was obtained from the elevator to which the wheat crop was taken. Wheat from the fallow and cover crop treatments were hauled separately. At Crowley’s, wheat and safflower yields were recorded from the yield monitor that was installed on the combine. Samples were sent to a private laboratory for protein (wheat) or oil (safflower) content determination. Grain moisture and test weight (density) were measured as well.

g. Earthworm Surveys: Earthworm surveys were conducted in September of 2015 at all sites, by using the Mustard Extraction method5. No earthworms were detected. Concern was raised that the Mustard Extraction Method may not be effective in detecting the species of worms present in the project area. In response to this concern, research center and Extension staff conducted surveys using the Mustard Extraction Method and the Hand Sorting Method side by side to determine which test was more accurate. The Hand Sorting method was determined to be a better method of detection, since it detected more (1 earthworm) than the Mustard Extraction Method (0 worms). The Hand Sorting Method requires the removal and manual sorting of one cubic foot of soil to detect earthworms. If earthworms were detected, then the following information was recorded: total number of earthworms, number of earthworms by age (adult or juvenile), number of earthworms by species, total weight of all earthworms, total weight by species, and total weight by age. In September of 2016 and May of 2017, earthworm surveys were conducted in each treatment (cover crop areas and fallow) at all on-farm trial sites, and in the control (fallow) plots of the first and second replications at the research center trials to prevent damage to recently planted cover crops. We found few earthworms (generally no more than one) in some of the trials in 2016 or 2017; hence, the earthworm data will not be presented in this report.

h. Economic analysis: Economic Analysis was conducted for all project trials. Management data was collected from each farm and organized into an excel sheet to show different management decisions and their associated costs, for each treatment. This data was then sent to the Agriculture & Business Management Economist for analysis. The Economist used the management decision data to create enterprise and field budgets for each treatment type (cover crop vs. control/fallow) at each trial.

5 Gunn, A. 1992. The use of mustard to estimate earthworm populations. Pedobiologa 36:65-67. Also, Singh, J., S. Singh, and A.P. Vig. 2016. Extraction of earthworm from soil by different sampling methods: a review. Environ Dev Sustain 18 (6): 1521-1539.

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Direct costs, gross receipts, and net returns were determined for each treatment on a per acre basis and per yield unit basis (bushel, lb, etc.) or a per field basis, depending on their field management practices. The costs, receipts, and overall profits for each treatment were then compared between treatments, for each trial. Some direct costs were standardized across all trials in order to decrease variability between trials. Herbicide cost (on a per acre basis) was standardized for each type of herbicide used (glyphosate, 2,4-D Amine, Dicamba, etc.), along with tillage treatments cost (disc, field cultivator, double disc drill, etc.). All other data was specific to each individual trial (yields, crop receipts, seed costs, etc.). The results of the economic analysis will be reported in a separate publication after wheat harvest in 2018.

2015-2017 RESULTS 1. Weather data

Precipitation and temperature data (where available) were collected from automated weather stations and from CoCoRaHs (https://www.cocorahs.org/) located in the counties where the field trials were conducted (Figure 2).

a. Precipitation: In 2015, total precipitation ranged from 14.3 in. in Yellow Jacket to 23.5 in. in Monticello (Table 3 in Appendix A). More precipitation was recorded with CoCoRaHs (17.0 in.) than with CoAgmet at the Southwestern Colorado Research Center in Yellow Jacket. This was also the case in Dove Creek vs. Dolores County. The reason for this is because the rain gage in CoCoRaHs is emptied manually and snow is melted so that moisture from snow is accounted for. The same is true for GHCN. In contrast, CoAgmet and SCAN use a tipping bucket rain gage that is not designed to capture all the snow or measure all the moisture from the snow that is captured, especially in windy or cold conditions. Hence, CoAgmet and SCAN likely underestimate total precipitation. This was confirmed in 2016 and 2017 in Yellow Jacket where the CoAgmet station and CoCoRaHs rain gage are located close to each other. May and June 2015 precipitation was above normal at all the weather stations (Table 3 & Table 4 in Appendix A). July and October were also above normal, except in Yellow Jacket. The 2016 CoAgmet and SCAN precipitation was markedly below normal (Table 4 & Table 5 in Appendix A). CoCoRaHs and SCAN was about normal, which underscores the fact that CoAgmet and SCAN do not measure all the moisture from snow. March, April, June, September, and October 2016 precipitation were below normal. Twenty seventeen was the driest year of the 2015-2017 period (Table 6 in Appendix A). Only January and July had above normal precipitation. The fall was extremely dry.

https://www.cocorahs.org/

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Figure 2. Weather Station Locations

b. Temperature: The average temperature in Yellow Jacket was below normal in 2015,

2016, and 2017 (Table 7 in Appendix A). It was closer to normal in Dove Creek, although there were a lot of missing data in 2015 and 2016 (Table 8 in Appendix A). The year 2017 was generally warmer than the 2007-2017 average in Eastland while 2015 and 2016 were slightly warmer or cooler depending on the year and month (Table 9 in Appendix A). Monticello had generally warmer fall and winter than normal (Table 10 in Appendix A).

2. Research Center Trials Two cover crops trials were conducted at the Southwestern Colorado Research Center (SWCRC), SWCRC #1 and SWCR #2. The soil type at both trials is Wetherill silty clay loam.

a. SWCRC #1 i. Trial information (Table 11 in Appendix A, Figure 3 in Appendix B)

Cropping system: No-till (NT) winter wheat-fallow Treatments (in fallow year):

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• Fallow with no cover crops (Fallow) • Three cover crop mixtures (CCM)

o CCM1: Yellow sweet clover, hairy vetch, and winter pea o CCM2: Yellow sweet clover, hairy vetch, winter pea, and winter rye o CCM3: Yellow sweet clover, hairy vetch, winter pea, winter rye,

Winfred turnip, and winter canola

The seeding rate and seed cost, and the percentage of each species in the mixture are shown in Table 15. SWCRC #2 Trial Information – Conventional Tillage (Soil Type: Wetherill Loam, Sharps-Cahona). Plot size

• CCM: 20 ft. by 200 ft. • Fallow: 60 ft. by 200 ft.

Experimental design: Randomized complete block (RCB) with three replications Field operations: The plot area was in winter wheat in 2014-2015. Wheat was harvested on 07/23/2015. The whole plot area was sprayed with Roundup PowerMax (active ingredient: glyphosate) at 48 oz/acre on 09/18/2015. Cover crops were planted on 09/28/2015 with a NT drill leased from the High Desert Conservation District. The fallow plots were sprayed with Roundup PowerMax 0n 04/21/16 at 32 oz/acre. The cover crops were mowed with a brush hog on 06/10/2016. The whole plot area was sprayed on 06/17/16 with Roundup PowerMax at 2 pts/acre plus 2.4-D Amine at 0.5 pt/acre and with Roundup PowerMax at 1 qt/acre on 8/3/16 and at 1.25 qts/acre on 09/17/16. Fairview winter wheat was planted on 09/20/2016 with a Great Plains drill at 50 to 55 lbs/acre and was harvested on 07/20/2017. The whole plot area was sprayed with Roundup PowerMax at 40 oz/acre on 8/23/2017 and cover crops were planted with the same NT drill as in 2015 on 08/30/2017. The cover crop mixtures were similar to those planted in the fall of 2015, with minor modifications (Table 11). No fertilizer was applied to winter wheat or CCM in 2015-2017 to mimic management practices on farmers’ fields. A composite soil sample (0-6” depth) from the whole plot area was taken prior to CCM planting in 2015 and analyzed with the Haney method. Soil pH was 6.6, soil organic matter (SOM) was 1.9%, and available N, P2O5, and K2O were 64.5, 44.6, and 62.1 lbs/acre, respectively. Further testing was performed prior to wheat planting in 2016 and cover crop planting in 2017, in Fallow and CCM (Table 12). Plant canopy in CCM2 and CCM3 was similar since no brassicas survived the winter, hence only CCM1 and CCM2 were assessed for soil nutrient availability with the Haney and traditional soil testing methods. Other soil measurements included PLFA, soil water content, and water infiltration rate.

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Table 12. Soil test results at SWCRC #1 in the fall of 2015, 2016, and 2017 (Sample depth 6 inches)

SWCRC #1 Fall 2015 Fall 2016 Fall 2017

Whole plot area Fallow CCM1 CCM2 Fallow CCM1 CCM2&3

pH 6.6 6.8 6.7 7.0 7.1 7.1 7.2 OM (%) Traditional NA 1.6b* 1.7a 1.6b 1.7 1.6 1.9 Haney 1.9 NA NA NA 2.2 2.2 2.1 N (lbs/acre) Traditional (NO3-N) NA§ 62.3 35.3 37.3 7.7b* 10.3a 10.0a Haney (Available N) 64.5 66.8 43.5 45.6 15.6b* 19.2ab 20.8a P2O5 (lbs/acre) Traditional NA 84.9 73.6 82.0 73.9 62.0 66.9 Haney 44.6 72.2 76.2 94 76.7 71.2 75.6 K2O (lbs/A) Traditional NA 362.2 408 389.5 425.7 388.7 402.4 Haney 62.1 85.5 83.2 85.0 87.7 76.6 78.7 HANEY Solvita CO2, ppm C 19.2 17.7 21.7 21.5 15.7 17.5 18.8 Organic C:N (Haney) 6.4 9.5 10.1 9.0 11.4 10.9 10.1 Soil Health (Haney) 5.1 3.5 4.0 4.4 5.0 5.0 4.6 PLFA SWCRC #1 Fall 2015 Fall 2016 Total biomass (ng/g) 872.0 584.1 1030.1 925.1 Bacteria (%) 47.8 42.7 53.2 40.3 Fungi (%) 7.8 3.9 7.3 3.4 Protozoa (%) 0.0 0.0 0.0 0.0 Undifferentiated (%) 44.4 53.4 39.5 56.4 Diversity Index 1.4 1.2 1.3 1.2 Rating > Avg. Avg. > Avg. Avg.

*Means followed by the same letter are not significantly different at alpha=0.05. §Not Available

ii. Results

1. Cover Crops Soil water content in the top 2.0 ft. averaged 10% by weight at planting, which was at or below the wilting point. A rainstorm (0.56”) on Oct. 5th induced cover crop seed germination followed by plant emergence about a week later. Seedlings of rye, winter pea, hairy vetch, and volunteer wheat were observed on Oct. 12th. There was a significant rainfall (0.83”) on Oct. 19th and the first freeze occurred on Oct. 28th, which was later than normal. Precipitation in November and

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December 2015 and in January 2016 was above normal. The spring of 2016 was dry, except for the month of May. Plant biomass as measured on June 9, 2016 was substantial and much higher than on farmers’ fields. Cover crop mixture #3 produced more biomass than CCM1 or CCM2 but the difference was not significant (Table 13). Canopy cover averaged 89% in all three CCMs. Cover crop mixtures 2 & 3 included winter rye while CCM1 only had legumes, which may have contributed to less cover crop cover and more volunteer wheat in CCM1. Winter rye was more present in CCM3 (68%) than in CCM2 (50%) and may explain the higher plant biomass in CCM3 (Data not shown). No brassicas were observed in CCM3, either due to poor germination or winter kill. Dry seedbed and late planting may have contributed to the failure of brassicas in 2016. Our experience growing winter canola at the SWCRC indicate that the optimum planting date for winter brassicas is late August to early September. Among the legumes, winter pea was the most present followed by hairy vetch. There was no yellow sweetclover in all three cover crop mixtures at termination. Sweetclover was introduced to North America from Europe as a forage crop. It can be annual or biannual and has small seeds, hence it should not be planted deeper than 0.5 in.6 It is well adapted to SW Colorado and can be found in pastures, prairies, road ditches, etc.

Table 13. Plant biomass and canopy cover at SWCRC #1 on 6/8/2016

Treatment Plant DM (lbs/acre)

Canopy cover (%)

Volunteer wheat (%)

Cover crop

cover (%) Ground

cover (%)

CCM1 4066.7 88.8 35.2 53.7 83.3

CCM2 4336.7 88.8 25.9 61.1 90.7

CCM3 5033.3 88.8 20.4 66.6 92.6

LSMEAN 4478.9 89.0 27.0 54.9 89.0

CV (%) 25.1 11.0 38.6 28.3 13.1

Pr > F 0.6 1.0 0.08 0.44 0.37

Seed size may be an issue in how cover crops are planted. In this project, the seeds of all cover crop species in the mixture were mixed in the pre-determined proportions and planted. Depending on the type of planter/drill used and how it is calibrated, this may affect seed flow and distribution in the seed row. Moreover, by mixing all the seeds together, seeding depth cannot exceed that recommended for small-seeded species (e.g., 0.5” or less) or their emergence will suffer. This is particularly relevant in the project area where soils tend to form a crust after a rain

6 Ogle, D., L. St. John, and D. Tilley, D. 2008. Plant Guide for yellow sweetclover (Melilotus officinalis (L.) Lam. And white sweetclover (M. alba Medik. USDA-Natural Resources Conservation Service, Idaho Plant Materials Center, Aberdeen, ID.

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event. Ideally, the smaller and larger seeds should be placed in separate boxes to better control their seeding rate and depth. In this trial, the NT drill was calibrated to deliver 28.9 lbs/acre for CCM1, 35.2 lbs/acre for CCM2, and 28.2 lbs/acre for CCM3. However, the actual seeding rates were 30.1, 45.7, and 38.7 lbs/acre, respectively. A better match was achieved in 2017 between the intended and the actual seeding rates. Microbial biomass in CCM in September 2016 (prior to wheat planting in 2016) was almost twice that of Fallow but the difference was not significant (Table 12). The coefficient of variation was 49%.

2. Winter Wheat Total precipitation from snow and rain from wheat planting on September 20, 2016 through June 2017 was 12.47 inches. The fallow treatment had significantly more moisture in the top three feet of soil at wheat planting than the cover crop treatments (Table 14). Nitrate N in the top 6.0 inches of soil averaged 62.3 lbs/acre in Fallow and 36.3 lb/acre in CCM (Table 12). Total available N as measured by the Haney method was 66.8 lb/acre in Fallow and 44.5 lb/acre in CCM. These differences in soil water content and available N may explain the significantly higher wheat yield in Fallow (60.1 bu/acre) than in CCM (44.1 bu/acre). Grain protein concentration was also higher in Fallow than in CCM (13.2% vs. 12.2%). Differences among the cover crop treatments were not significant at α = 0.05 (Table 14). The overall wheat yield of 48.1 bu/acre was above the county average of 21 bu/acre. There were no significant differences in soil chemical properties (e.g., pH, OM, P, K, S, CEC) between Fallow and CCM prior to CCM planting in 2017, except for nitrate N. Nitrate N amounts were low in both Fallow (7.7. lbs/acre) and CCM (10.3 lbs/acre) but the difference was significant at α = 0.09. Available N as measured by Haney was approximately twice (20 lbs/acre in CCM and 15.6 in Fallow) that of NO3-N (Table 12). This could be due differences in methodology and the fact that Haney N includes potentially mineralizable N in addition to nitrate and ammonium N. Organic matter averaged 1.6% in CCM1, 1.9% in CCM2&3, and 1.7% in Fallow. The Haney test shows higher SOM (2.2 in CCM1 and Fallow and 2.1 in CCM2&3) even though both soil tests use the same method (LOI) to measure SOM. Solvita CO2-C was higher in CCM (18.1 ppm C) than in Fallow (15.7 ppm C), but the difference was not significant at α=0.24. Similarly, there was more K2O in Fallow (87.7 lbs/acre) than in CCM (77.6 lbs/acre) but not significantly (Table 12). The soil was fairly dry, particularly below 6 to 8 inches, prior to CCM planting in late August 2017, regardless of the treatment. Soil moisture averaged 13.3% by weight in the top foot and 9.6% in the second foot. The soil was too dry below 2 ft. to sample with the Giddings probe (Data not shown).

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Table 14. Soil moisture, infiltration rate, and wheat yield at SWCRC #1

Treatment 0-3 ft. Soil

moisture (g/g, %) Infiltration rate

(in/hr) Wheat Yield

(bu/acre) Grain Protein

(%) (September 2016) (September 2016) (July 2017) (July 2017)

CCM1 12.6 1.10 45.7 12.0

CCM2 12.1 0.85 45.5 12.3

CCM3 NA NA 43.2 12.3

Fallow 17.8 0.28 61.4 13.2

CV (%) 16.9 29.16 2.9 2.9

Pr > F 0.03 0.18 0.00 0.03

b. SWCRC #2 i. Trial information (Table 15 & Table 16 in Appendix A, Figure 4 in Appendix B)

Crop rotation: winter wheat-fallow Treatments during the fallow year:

• Tillage: NT and CT o Cover crops (Table 17)

Fall-planted: CCM1…CCM5 Spring-planted: CCM6, CCM7, CCM8

o Fallow with no cover crops

Plot size • CCM: 12 ft. by 100 ft. • Fallow: 30 ft. by 100 ft.

Experimental design: Split plot with tillage assigned to the main plots and cover crops or fallow to the sub-plots. Number of replications: three Cropping history and field operations: The plot area was in winter wheat in 2015-2016. Wheat was harvested on 07/28/2016. It averaged 43 bu/acre with a protein content of 19.8%. The NT plots were sprayed with Roundup PowerMax (active ingredient: glyphosate) and 2,4-D Amine at 32oz/acre and 8 oz/acre respectively, on 6/17/2016. The CT plots were disked on 8/8/16. Cover crops mixtures CCM1 through CCM5 were planted on 08/11/2016 with a NT drill leased from the High Desert Conservation District. The CT fallow plots and the CT plots to be planted to CCM6-8 were disked on 9/19/16. They were chisel-plowed on 3/20/17 and cultivated on 4/7/17. The NT fallow plots and the NT plots to be planted to spring cover crops (CCM6-8) were sprayed with Roundup PowerMax on 10/17/16 at 40 oz/acre and again on 4/12/17. Spring cover crop mixtures CCM6-8 were planted on 4/13/17. The Aug.’16-planted cover crops were mowed with a brush hog on 6/20/17. All the CCM plots were disked on 6/23/17 in the CT treatment. They were sprayed with Roundup PowerMax at 32 oz/acre plus 2,4-D Amine at 8 oz/acre in NT on 6/21/17. All the CT plots were cultivated (FC with sweep

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attachments) on 8/4/17 as were the spring-planted CCM plots and the fallow plots on 9/20/17. The Aug.’16-planted CCM plots had a lot of stubble/plant residue. Hence, they were disked on 9/21/17. Fairview winter wheat was drilled in the CT and NT plots at 55 lbs/acre on 9/22/17. No fertilizer of any kind was applied to any of the treatments in 2016 or 2017.

Table 17. Cover Crop Mixes in SWCRC#2

Cover Crop Mixture

Seeding rate (lbs/ac)

Seed cost

($/ac) Cover Crop Species (% by weight) Planting

date Termination

date

CCM1 24.7 27.59

Winter Pea (67%), Berseem Clover (4%), Yellow Sweet Clover (1%), Sorghum-Sudangrass (11%), Proso millet (8%), Teff (4%), Nitro Radish (2%), Purple Top Turnip (1%), Sunflower (2%)

8/11/2016 6/20/2017

CCM2 33.1 27.70 Winter Pea (85%), Flax (10%), Nitro Radish (3%), Rapeseed (1%), Impact Forage Collards (1%)

CCM3 43.0 27.81 Winter Pea (66%), Winter Triticale (31%), Rapeseed (2%), Purple Top Turnip (1%)

CCM4 35.1 25.44 Winter Pea (54%), Yellow Sweet Clover (4%), Winter Triticale (38%), Rapeseed (2%), Nitro Radish (2%)

CCM5 38.0 31.27

Winter Pea (50%), Hairy Vetch (8%), Winter Triticale (35%), Sorghum-Sudan (5%), Nitro Radish (2%)

CCM6 24.3 14.03 Hairy vetch (14%), spring pea (16%), spring oat (24%), rapeseed (1%), flax (2%), safflower (4%)

4/13/2017 6/20-23/2017 CCM7 10.0 15.40

Balansa clover (40%), crimson clover (20%), annual ryegrass (30%), EcoTiller radish (10%)

CCM8 22.4 10.06 Crimson clover (2%), spring pea (67%), spring barley (25%), Nitro radish (7%)

Soil test results prior to cover crops planting in August 2016: Soil pH in 0-6 in. averaged 6.7, SOM 1.5%, NO3-N 23.2 lbs/acre, P2O5 68.3 lbs/acre, and K2O 411.0 lbs/acre with no significant differences between CT and NT (Table 18). The Haney test showed less P2O5, K2O, and Nitrate N. Available N averaged 33.1 lbs/acre. There was significantly more Solvita CO2-C in CT (49.5 ppm) than in NT (24.2 ppm). The soil health index was also significantly higher in CT (5.2)

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than in NT (3.2). Conversely, NT had noticeably, but not significantly, greater microbial biomass and diversity index than CT (Table 18). Most of the microbial biomass was from bacteria or undifferentiated microbes. The differences between CT and NT may be due to tillage but it is too early to draw conclusions given that less than a month had passed since the CT and NT treatments were established.

Table 18. Soil test results at SWCRC #2 prior to CCM planting in August 2016 (Sample depth 6 inches)

Type of analysis/Sampling period Fall 2015 Composite

Tillage (August 2016)§ August 2016 Average CT NT

Traditional Soil Analysis Organic Matter LOI, % N/A 1.5 1.5 1.5 FIA Nitrate N lbs/ac N/A 23.0 23.3 23.2 P2O5 lbs/ac N/A 70.0 66.7 68.3 K2O lbs/ac N/A 435.6 386.5 411.1 Haney Soil Health Analysis pH pH 6.8 6.7 6.7 6.7 Organic Matter LOI % 2 1.5 1.6 1.5 Available N lbs/ac 49.6 35.4 30.8 33.1 P2O5 lbs/ac 87.0 33.9 29.5 31.7 K2O lbs/ac 112.1 76.4 67.1 71.8 Solvita CO2 ppm C 34.7 49.5a* 24.2b 36.9 Organic C:N ratio 7.2 13.1 13.4 13.3 Soil Health Index 7.0 5.2a* 3.2b 4.2 PLFA - Soil Community Microbial Analysis Total biomass ng/g 873.8 835.5 1110.1 972.8 Bacteria % 52.8 56.5 54.2 55.3 Fungi % 3.7 3.6 7.4 5.5 Protozoa % 0.0 0.0 0.1 0.2 Undifferentiated % 43.6 39.9 38.3 39.1

Diversity Index (1.1 to 1.6) 1.2 Average 1.2 Average 1.4 Good 1.3 Average

§Average of three replications/composite samples *Means followed by different letters are significantly different at α = 0.05.

ii. Results

1. Cover Crops At CCM planting on August 11, 2016, there was some moisture in the top 6.0 inches of soil in CT and NT and in 6-12” in NT but very little moisture below that (Table 19). The Fallow and CCM plots were managed similarly prior to CCM planting, hence soil moisture was measured in the fallow plots only. A little over

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an inch of rain fell on August 23-25, triggering seed germination. October was dry as was the spring of 2017, except for May (Table 5 & Table 6). Above normal winter precipitation resulted in good soil moisture at cover crop planting on April 13, 2017 (Table 19). Both the August 2016- and April 2017-planted cover crops were terminated on 20-23 June 2017; which was 10-13 days later than in 2016. Plant biomass of the August-planted cover crops (CCM1 thru CCM5) averaged 3412 lbs/acre in CT and 3463 lbs/acre in NT, with no significant differences between the tillage treatments or among the cover crops mixtures (Table 20). Volunteer wheat represented 72 to 94% of the total plant biomass and volunteer wheat plus weeds made up 96.8 to 99.9% of the biomass. The cereals, brassicas, and legumes that were in the mixture contributed very little or no biomass. Soil moisture content was much higher prior to or at CCM planting in early April 2017 than in August 2016 (Table 19) due to above normal precipitation in December 2016 and January 2017. March, April, and June precipitation was below normal while May was about normal. The April-planted cover crops produced significantly less biomass than the August-planted ones (Table 20) due to the shorter growing season (fewer growing degree days) in addition to the dry spring. On the upside, volunteer wheat was not much of an issue in the spring-planted CCMs, particularly with NT (Table 20). This was to be expected since there was more time to control weeds before planting cover crops in April 2017 than in August 2016. Barley or oat contributed 50% to the total biomass, while legumes (mostly peas) contributed 36% on average and brassicas (rapeseed) 1.1% in CCM6 and 9.5% in CCM8. There was some hairy vetch in CCM6 (2 to 5%) and no crimson clover in CCM8 (Data not shown). Similarly, there was no safflower or flax in CCM6 at termination. CCM7 was not sampled due to poor establishment.

Table 19. Gravimetric soil moisture at SWCRC#2

Treatment

Soil depth (in.)

Average soil moisture by weight (%)

8/11/2016 Pre-CCM Planting

4/12/2017Pre-CCM Planting

8/12/2017

Tillage Fallow or CCM

Post Aug.’16-Planted

CCM

Post April’17-Planted

CCM

CT CCM 0-12 NA 18.3% 11.5% 11.9% CT CCM 12-24 NA 19.6% 11.0% 16.3% CT CCM 24-36 NA 18.3% 10.6% 15.7% CT CCM 36-48 NA 16.5% NA NA CT Fallow 0-12 12.8% (0-6”) 18.8% 17.0% CT Fallow 12-24 9.5% (6-12”) 18.7% 17.1% CT Fallow 24-36 8.8% (12-24”) 18.3% 16.7% CT Fallow 36-48 NA 18.3% NA* NT CCM 0-12 NA 20.1% 12.9% 12.0%

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Treatment

Soil depth (in.)

Average soil moisture by weight (%)

8/11/2016 Pre-CCM Planting

4/12/2017Pre-CCM Planting

8/12/2017

Tillage Fallow or CCM

Post Aug.’16-Planted

CCM

Post April’17-Planted

CCM

NT CCM 12-24 NA 20.1% 11.8% 15.0% NT CCM 24-36 NA 18.3% 10.7% 15.9% NT CCM 36-48 NA NA* NA NA NT Fallow 0-12 13.6% (0-6”) 19.6% 14.2% NT Fallow 12-24 12.8% (6-12”) 20.0% 18.1% NT Fallow 24-36 8.3% (12-24”) 18.7% 17.5% NT Fallow 36-48 NA 16.8% NA*

CV (%) 2.9 9.7 Pr > F (CCM)

Tillage 0.06 (NT>CT) 0.88 CCM 0.45 0

Depth 0 0 Tillage x CCM 0.81 0.72

Tillage x Depth 0.03 0.94 CCM x Depth 0.54 0

*The soil was too wet or too compacted (naturally or due to the pressure exerted by the hydraulic probe) to get a good sample.

Table 20. Plant Biomass Production Summary at SWCRC #2 (Sample dates: 6/19/ 2017 & 6/20/2017)

CCM Plant Biomass lbs DM/acre Contribution (% of DM)

CT NT Average Cereals Legumes Brassicas Volunteer Wheat

CCM1 3235.8 3683.7 3459.7a* 0.0 0.6 0.0 93.8 CCM2 3190.5 3514.5 3352.5a 0.0 3.2 0.0 83.4 CCM3 3269.9 3428.7 3349.3a 0.0 0.1 0.0 84.1 CCM4 4011.8 3146.7 3579.2a 0.0 1.1 0.0 78.2 CCM5 3353.9 3541.5 3447.7a 0.0 0.9 0.0 84.2 CCM6 763.8 662.5 713.2b 49.6 38.3 1.1 10.9 CCM8 1003.4 650.1 826.8b 50.1 32.9 9.5 7.5 CV (%) 31.1 Pr > F Tillage 0.91 CCM < 0.001

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*Means followed by the same letter are not significantly different at α = 0.05. Tillage or Tillage by CCM had no significant impact on plant biomass.

There was less NO3-N in the top six inches of soil in SWCRC #2 than in SWCRC #1 prior to cover crop planting in August 2016 and April 2017 (Table 12 & Table 21). The same was true prior to wheat planting. The NT treatment had significantly more NO3-N than CT. There was significantly more NO3-N and Haney available N in the Fallow than in the August 2016- or April 2017-planted CCM treatments (Table 21). The August-planted CCMs produced more biomass and depleted more soil N than the spring planted CCMs. Solvita CO2-C was significantly higher in CT than in NT in the Fallow and the April 2017-planted CCM. Soil organic matter was quite high compared to what it was in August 2016 (1.5%). The greater SOM in September 2017 than in August 2016 may be due to differences in sampling (e.g., # samples) than to CCM. There were no significant differences in microbial biomass or composition in August 2017, even though microbial biomass was 62 to 68% higher in CCM than in Fallow under CT management (Table 21). Variability in microbial biomass (CV of 32%) and Protozoa (CV of 196%) was high. There was more moisture in the top 3-ft of soil at wheat planting in Fallow (17%) than in CCM, regardless of tillage (Table 19). The soil was much drier below 0-1 ft. after the August-planted CCMs than after the April-planted CCMs, which would be expected since the August 2016-planted CCMs produced much more biomass and hence depleted more soil moisture than the April 2017-planted CCMs. The soil moisture samples were taken on 8/12/2017 with the Giddings probe and winter wheat was planted on 9/22/2017. July rainfall (2.30”) was above normal while August rainfall (0.57”) was below normal.

2. Winter Wheat Wheat was drilled in the whole plot area on 9/22/17 and will be harvested in July 2018.

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Table 21. Soil test results at SWCRC #2 in September 2017 (Sample depth 6 inches)

Tillage/Treatment (Aug.’16 and Apr.’17 planted CCM and Fallow)

CT NT Average Aug.’16

CCM Apr.’17

CCM Fallow Aug.’16 CCM

Apr.’17 CCM Fallow Aug.’16CCM Apr.’17

CCM Fallow

Traditional Soil Test Analysis Organic Matter (LOI, %) 2.3 1.9 1.9 1.8 1.8 1.8 2.1 1.9 1.9 FIA Nitrate N (lbs/ac) 11.0 17.5 30.0 14.2 17.8 31.3 12.6c* 17.7b 30.7a P2O5 (lbs/ac) 44.0 49.8 50.3 43.1 46.7 49.5 43.5b* 48.3a 49.9a K2O (lbs/ac) 304.3 319.1 320.2 294.9 289.1 300.0 299.6 304.1 310.1 CEC (Me/100 g) 14.8 15.2 15.4 15.0 15.9 15.3 14.9 15.6 15.3 Haney Soil Health Analysis pH 7.0 6.9 6.8 6.9 6.9 6.8 6.9 6.9 6.8 Organic Matter (LOI, %)§ 1.8 2.0 1.9 2.0 1.8 1.8 1.9 1.9 1.9 Available N (lbs/ac) 21.1c* 29.0ab 35.4a 24.6bc 23.4bc 33.5a 22.8 26.2 34.5 P2O5 (lbs/ac) 40.6 42.0 45.3 38.3 45.6 43.2 39.4 43.8 44.3 K2O (lbs/ac) 63.2 67.7 64.7 60.7 57.0 57.9 61.9 62.3 61.3 Solvita CO2 (ppm C) 14.8ab* 21.7a 19.2ab 14.3ab 10.2b 11.0b 14.5 15.9 15.1 Organic C:N 9.3 8.6 8.6 8.3 8.0 6.4 8.8 8.3 7.5 Soil Health Index 3.9ab* 5.0a 5.0a 3.8ab 3.4b 3.5ab 3.8 4.2 4.3 PLFA - Soil Community Microbial Analysis (There were no significant main or interaction effects at α = 0.05) Total biomass (ng/g) 1484.9 1431.6 884.2 1054.3 1105.9 1101.4 1269.6 1268.7 992.8 Bacteria (%) 46.8 52.9 49.5 51.8 48.2 54.8 49.3 50.6 52.1 Fungi (%) 12.2 14.2 11.8 11.2 9.4 11.6 11.7 11.8 11.7 Protozoa (%) 0.2 0.2 0.0 0.1 0.0 0.0 0.1 0.1 0.0 Undifferentiated (%) 37.8 32.7 38.7 37.0 42.4 33.6 37.4 37.5 36.2 Diversity Index (1.1 to 1.6) 1.5 1.5 1.5 1.4 1.4 1.5 1.5 1.5 1.5

*Means followed by different letters are significant different at α=0.05. §Even though Tillage*Treatment was significant, the Tukey-Kramer mean comparison was not significant at α=0.05.

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3. On-Farm Trials

Barry Farm

The tests at Barry’s farm are carried out in four adjacent fields: Barry North, Barry Middle, Barry Southwest East half, and Barry Southwest West half (Figures 5 through 8 in Appendix B). The soil type in the Southwest and Middle fields is the Cahona Series, and the soil type in the North field is the Monticello Series. Crop rotation is winter wheat-fallow with NT management.

a. Barry Middle (approx. 69 acres)

i. Test information (Table 22 in Appendix A)

This field was planted to winter wheat in 2014 and 2015. After wheat harvest on 8/15/2015 and an herbicide application on 9/2/2015, Juniper hard red winter wheat was drilled on 9/6/2015 at 30 lbs/acre. On the same day, yellow sweet clover was broadcast-seeded at 4.0 lbs/acre in the whole field, except for a control strip of approximately 8.0 acres. Wheat was sprayed with Dicamba + 2.4-D on 4/2/2016 to control weeds and terminate the yellow sweet clover. It was harvested on 8/11/2016. The whole field was sprayed with a mixture of Buccaner, 2, 4-D, and Banvel on 8/22/2016. A six-species cover crop mixture was planted in 04/14/2017 at 24.2 lbs/acre in three large strips (Figure 5). The mixture consisted of spring peas (62%, 19%), hairy vetch (14%, 17%), spring oats (16%, 24%), rapeseed (1%, 18%), safflower (4%, 6%), and flax (2%, 16%). The numbers between parentheses represent the percentage of the species by weight and by number of seeds, respectively. Two control strips were left fallow between the cover crop strips. The CCM strips were sprayed with Dicamba+Glyphosate+2,4-D on 6/19/2017 to terminate the cover crops and control weeds in the fallow strips (Table 22). Juniper hard red winter wheat was planted on 8/29/2017 in the whole field at 35 lbs/acre. It will be harvested in July or August of 2018. Prior to CCM planting in March 2017, this field had little available N but plenty of P and K in the top 6.0 inches of soil (Table 23). As was pointed elsewhere, the Haney method usually shows less P and much less K than the traditional soil test analysis. There were large variations in Olsen P, particularly in the Fallow strips. Soil pH averaged 8.0 in the CCM strips and 7.9 in the Fallow strips. The organic C:N ratio was significantly higher in the CCM than in the Fallow strips. Microbial biomass was on average higher in CCM than Fallow, but the difference was not significant.

Table 23. Barry Middle March Soil Data (Sample date 3/17/2017, sample depth 6 inches)

CCM CCM CCM CCM Fallow Fallow Fallow Strip 1 Strip 2 Strip 3 LSMEANS Strip 1 Strip 2 Average Traditional Soil Test Analysis pH 7.9 8.0 8.0 8.0 7.9 7.8 7.9 LOI SOM (%) 1.4 1.3 1.3 1.3 1.4 1.6 1.5 NO3-N (lb/ac) 3.4 3.4 3.0 3.0 3.6 4.8 3.5

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CCM CCM CCM CCM Fallow Fallow Fallow Strip 1 Strip 2 Strip 3 LSMEANS Strip 1 Strip 2 Average Traditional Soil Test Analysis Olsen P (lb P2O5/ac) 53.6 104.5 88.0 82.0 130.6 11.9 74.2 AC K (lb K2O/ac) 583.0 597.5 609.5 596.7 602.3 739.6 677.4 CEC (meq/100 g) 17.9 17.6 17.6 17.7 17.4 14.8 16.1 Haney pH 7.9 8.0 8.0 8.0 7.9 7.8 7.9 LOI SOM (%) 1.4 1.3 1.4 1.4 1.4 1.6 1.5 Available N (lb/ac) 6.8 10.7 7.3 8.3 8.9 11.1 10.0 Available P (lb P2O5/ac) 30.4 26.5 32.4 29.8 35.2 45.3 40.3 Available K (lb K2O/ac) 68.5 75.2 74.9 72.9 72.5 119.2 95.9 Solvita CO2- ppm C 14.6 16.1 19.2 16.6 16.1 21.1 18.6 Organic C:N 17.5 16.8 17.5 17.3a* 15.3 14.9 15.2b Soil Health Index 2.93 2.93 2.88 2.9 3.08 3.86 3.5 PLFA (mid-May) Microbial biomass (ng/g) 2036.8 2026.8 1156.2 1739.9 1477.7 769.1 1036.2 Bacteria (%) 46.6 35.7 47.2 43.2 43.5 48.9 46.2 Fungi (%) 15.0 11.0 16.3 14.1 13.3 15.7 14.5 Protozoa (%) 0.5 0.0 0.0 0.2 0.0 0.0 0.0 Undifferentiated (%) 37.9 53.3 36.5 42.6 43.2 35.4 39.3 Diversity Index 1.6 1.4 1.5 1.5 1.5 1.6 1.5

*Means followed by the same letter are not significantly different at α=0.05.

ii. Results

1. Wheat yield (2015-2016) The seedbed was fairly dry at wheat planting in 2015. Precipitation in Eastland and Monticello in 2015 was above the 30-year average at the SWCRC, particularly in May through July and in October (Table 3 & Table 4). However, the winter of 2015-2016 and spring of 2016 were dry with the exception of May. Wheat yield in 2016 averaged 31 bu/acre, with the control (34 vs. 28 bu/acre) surpassing the strip where yellow sweet clover (YSC) was broadcast in early September 2015 and terminated in early April 2016 (Table 22, Appendix A). Grain protein was similar (11.9%) in the control and the YSC strip. The difference in wheat yield between the control and YSC may be the result of field variability and not YSC since the latter had a poor stand and produced little growth before it was terminated.

2. Cover crops There was good soil moisture at CCM planting in April 2017. It averaged 19% by weight in the top 2.0 feet of soil in the CCM and Fallow strips (Table 24). Rainfall following planting was below normal except in May. Plant biomass averaged 681 lbs/acre, with large variability within and between strips (Table 25).

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Spring oat and spring pea contributed approximately 42% to the total biomass each. Safflower contributed 12.5% and hairy vetch 2.2%. The biomass of rapeseed and flax was negligible. These percentages correlate somewhat with the presence or absence of each cover crop species in the plant canopy, with oat being present 25.6% of the time followed by spring pea (15.1%), hairy vetch (6.4%), and safflower (3.6%). Overall, cover crops represented 42% of the canopy cover. In terms of species seed mix composition, spring oat was the most present (24% by number of seeds), followed by spring pea (19%), rapeseed (18%), hairy vetch (17%), flax (16%), and safflower (6%). Hence, even though rapeseed, flax, and hairy vetch were present almost as much as spring pea in the seed mix, they were not as present in the plant canopy and produced very little biomass compared to spring oat and spring pea.

Table 24. Gravimetric soil moisture by weight at Barry Middle

Treatment Strip # Depth (in.) Soil Moisture (%)

4/6/2017 8/24/2017 CCM 1 0-12 19.3 10.0 CCM 1 12-24 19.2 10.6 CCM 2 0-12 18.9 9.1 CCM 2 12-24 19.9 9.0 CCM 3 0-12 18.4 7.9 CCM 3 12-24 18.2 9.1 CCM Average 0-24 19.0 9.3 Fallow 1 0-12 19.2 12.1 Fallow 1 12-24 19.6 14.6 Fallow 2 0-12 18.8 13.2 Fallow 2 12-24 18.8 15.9 Fallow Average 0-24 19.1 13.9

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Table 25. Plant Biomass & Canopy Cover at Barry Middle (Sample date 6/16/2017)

Plant Dry Matter (lbs/ac)* CCM Species Presence

(%)§ Plant species CCM CCM CCM CCM % of

Total strip 1 strip 2 strip 3 Average Spring pea 272.8 283.3 304.3 286.8 42.1 15.1

Oat 392.7 304.4 175.8 291 42.7 25.6 Safflower 43.1 185.9 26.5 85.2 12.5 3.6

Hairy vetch 28.5 12.5 3.4 14.8 2.2 6.4 Flax 6.1 1.5 0.3 2.6 0.4 0.2

Rapeseed 0.0 0.7 0.0 0.2 0 0.7 Weeds 7.6 0.6 1.2 3.1 0.5 NA

Total 744.7 786.8 511.2 680.9 100 % Cover Canopy Cover 49.0 51.0 29.0 42.9

Cover crop 49.0 49.0 28.0 41.8 Volunteer wheat 0.0 0.0 0.0 0.0

Weeds 1.0 2.0 1.0 1.1 Ground Cover 89.0 79.0 85.0 84.2

Bare Ground 11.0 21.0 15.0 15.8 Cover crop 0.0 0.0 0.0 0.0

Residue 89.0 79.0 85.0 84.2 Volunteer wheat 0.0 0.0 0.0 0.0

Weeds 0.0 0.0 0.0 0.0 *Average of three measurements per strip §Average of three strips and three measurements per strip

3. Winter wheat (2017-2018) Soil moisture on 8/24/17 (winter wheat was planted on 8/29/17) was generally low, but was significantly higher in Fallow (14%) than in CCM (10%), in the top 2.0 ft. Likewise, there was significantly more nitrate N in Fallow (25.0 lbs/acre) than in CCM (11.3 lbs/acre). The Haney test showed similar trends (Table 26). Soil pH was similar in March and August 2017 (Table 23 & Table 26). However, soil OM was approximately 0.5% higher in August than in March. Conversely, available P and K, Solvita CO2-C, and organic C/N were markedly higher in March than in August and this cannot be contributed to CCM since differences between CCM and Fallow in August were not significant, except for nitrate N. Some of these differences (e.g., available N) could be due to the timing of the soil sampling (spring vs. summer), others to unknown or unreported variations in the sampling procedure or methods of laboratory analysis, while others cannot be explained at this time.

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Wheat yield and quality data will be available in August 2018.

Table 26. Barry Middle August Soil Data (Sample date 8/24/2017, sample depth 6 inches)

CCM CCM CCM CCM Fallow Fallow Fallow Strip 1 Strip 2 Strip 3 Average Strip 1 Strip 2 Average Traditional Soil Test Analysis pH 8.1 8.1 8 8.1 8.1 8.1 8.1 LOI SOM (%) 1.9 1.7 1.7 1.8 1.9 1.9 1.9 NO3-N (lb/ac) 12.0 12.0 10.0 11.3b* 27.0 23.0 25.0a Olsen P (lb P2O5/ac) 38.5 35.3 50.0 41.2 53.2 38.5 45.8 AC K (lb K2O/ac) 416.8 416.8 455.3 429.6 465.0 424.0 444.5 CEC (meq/100 g) 18.5 18.1 16.8 17.8 18.4 21.5 20.0 Haney pH 7.4 8.1 7.8 7.8 8.0 8.0 8.0 LOI SOM (%) 1.8 1.9 2.2 2.0 1.9 2.0 2.0 Available N (lb/ac) 17.1 16.3 15.6 16.3 27.5 22.7 25.1 Available P (lb P2O5/ac) 38.5 34.3 35.1 36.0 36.8 28.1 32.5 Available K (lb K2O/ac) 57.4 52.9 62.7 57.7 63.3 49.1 56.2 Solvita CO2- ppm C 6.5 7.1 7.1 6.9 7.5 7.1 7.3 Organic C:N 11.5 13.6 12.8 12.6 9.7 10.5 10.1 Soil Health Index 3.5 3.55 3.44 3.5 3.88 3.61 3.7

*Means followed by the same letter are not significant at α = 0.05.

b. Barry West half, SW Field (approx. 53 acres)


This field was in continuous winter wheat in 2014-2016. Wheat was harvested on 7/24/2015. It averaged 22.5 bu/acre. After an herbicide application in early September, this field was again planted to winter wheat (Table 27, Appendix A). Yellow sweet clover (YSC) was broadcast-seeded to 47 acres at 4 lbs/acre, while approximately six acres were not seeded with YSC, for comparison. The areas with yellow sweet clover were sprayed with Dicamba+2.4-D in early April 2016 to control weeds and terminate the YSC. Wheat was harvested on 8/15/2016 and the whole field was sprayed with MB906 on 10/10/2016. On 4/13/2017, a four-cover crop species mixture (CCM) was planted in three strips totaling 40 acres at 22.4 lbs/acre with a double disc drill. The control consisted of two fallow strips totaling 14 acres (Figure 6). The CCM consisted of spring peas (67% by wt., 24% by seeds), crimson clover (2%, 21%), spring barley (25%, 36%), and Nitro radish (7%, 19%). It was terminated on 6/19/17 with the application of glyphosate+2,4-D+Dicamba and was planted to Juniper winter wheat on 8/29/17 at 35 lbs/acre. Soil pH in March 2017 averaged 7.8 in the strips to be planted to CCM and 7.9 in the Fallow strips (Table 28). Soil OM was also similar in CCM and Fallow (1.7-1.8%), while nitrate N was very low in both treatments. Solvita CO2-C was markedly higher in Fallow than in CCM but the difference was not significant. Soil health index was also higher in Fallow as was microbial biomass.

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Table 28. Barry WSW March Soil Data (Sample date 3/17/2017, sample depth 6 inches)

CCM CCM CCM CCM Fallow Fallow Fallow Strip 1 Strip 2 Strip 3 LSMEANS Strip 1 Strip 2 LSMEANS Traditional Soil Test Analysis pH 7.9 7.7 7.7 7.8 7.8 8.0 7.9 LOI SOM (%) 2.0 1.5 1.5 1.7 2.0 1.5 1.8 FIA Nitrate N (lb/ac) 4.0 2.0 2.0 2.7 4.0 3.0 3.2 Olsen P (lb P2O5/ac) 51.8 48.6 57.3 52.5 58.7 66.9 65.1 Amm. Ac. K (lb K2O/ac) 648.1 510.8 544.5 567.8 628.8 587.8 596.7 CEC (meq/100 g) 15.6 14.6 13.3 14.5 17.2 21.2 18.6 Haney pH 7.9 7.7 7.7 1.8 7.8 8.0 7.9 LOI SOM (%) 1.9 1.6 1.5 1.7 1.9 1.3 1.5 Available N (lb/ac) 12.0 7.1 8.4 9.2 20.8 8.0 14.0 Available P (lb P2O5/ac) 56.0 45.4 43.7 48.4 53.2 32.4 40.5 Available K (lb K2O/ac) 111.5 85.7 102.9 100.0 105.0 66.6 87.2 Solvita CO2- ppm C 21.1 16.8 36.4 24.8 59.7 14.6 43.0 Organic C:N 15.1 16.5 18.8 16.8 16.2 15.9 17.0 Soil Health Index 4.2 3.2 4.0 3.8 6.4 3.1 4.8 PLFA (mid-May 2017) Microbial biomass (ng/g) 1503.9 1865.5 1137.3 1502.3 2262.6 3765.2 2943.6 Bacteria (%) 40.3 51.4 50.5 47.4 49.8 38.9 44.4 Fungi (%) 12.2 13.4 14.3 13.3 13.5 10.9 12.2 Protozoa (%) 0.0 0.6 0.0 0.2 0.5 0.3 0.4 Undifferentiated (%) 47.5 34.7 35.2 39.1 36.1 49.9 43.0 Diversity Index 1.5 1.6 1.6 1.6 1.6 1.5 1.5

ii. Results

1. Cover crops Soil moisture in 0-2 ft. averaged 18% by weight and resulted in a good stand of cover crops (Table 29). Rainfall from planting to termination was below normal (1.4” at the SWCRC). Plant biomass averaged 704.3 lb/acre. Nitro radish (35%), barley (34%), and spring peas (29%) contributed the most to plant biomass (Table 30). Crimson clover biomass and presence was negligible, even though it represented 21% of the seed mix by number of seeds. There was 49% canopy cover, of which cover crops represented 47%. Spring barley and pea were encountered 22% and 18% of the time, respectively, compared to 15% for Nitro radish and less than 1% for crimson clover.

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Table 29. Gravimetric soil moisture by weight at Barry WSW

Treatment Strip # Depth (in.)

Soil Moisture (%) 4/6/2017 8/24/2017

CCM 1 0-12 18.9 10.4 CCM 1 12-24 18.0 12.0 CCM 2 0-12 17.6 11.5 CCM 2 12-24 17.2 13.1 CCM 3 0-12 17.3 10.1 CCM 3 12-24 17.8 9.2 CCM Average 0-24 17.8 11.0 Fallow 1 0-12 18.6 14.0 Fallow 1 12-24 18.6 15.9 Fallow 2 0-12 18.1 12.7 Fallow 2 12-24 17.6 14.8 CCM Average 0-24 18.2 14.4

Table 30. Plant Biomass and Canopy Cover at Barry SW West Half (Sample date 6/16/2017) Plant Dry Matter (lbs/ac)*

% Presence§ Plant species Transect 1 Transect 2 Transect 3 Average

% of Total

Nitro radish 363.4 266.7 103.9 244.7 34.7 14.7 Spring pea 171.5 235.7 199.6 202.3 28.7 17.8

Spring barley 261.3 202.4 248.8 237.5 33.7 21.8 Crimson clover 2.0 1.3 0.7 1.3 0.2 0.2

Weeds 8.5 0.0 47.1 18.5 2.6 NA Total 806.7 706.1 600.1 704.3 100 NA

% Cover*

Canopy Cover 57.0 42.0 47.0 48.7

Cover crop 57.0 41.0 41.0 46.7

Volunteer wheat 0.0 0.0 0.0 0.0

Weeds 0.0 1.0 5.0 2.0

Ground Cover 94.0 90.0 97.0 93.8

Bare Ground 6.0 10.0 3.0 6.2

Cover crop 0.0 0.0 0.0 0.0

Residue 93.0 90.0 97.0 93.6

Volunteer wheat 0.0 0.0 0.0 0.0

Weeds 1.0 0.0 0.0 0.2

*Average of three measurements per strip §Average of three strips and three measurements per strip

Soil moisture content on 8/24/17 was much lower than in early April prior to cover crop planting, even though 2.8 inches of rain fell since cover crop

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termination on 6/19/17 (Table 29). Nonetheless, there was significantly more moisture in the fallow strips (14%) than in the cover crop strips (11%). Likewise, there was significantly more nitrate N in Fallow (44.5 lbs/acre average) than in CCM (18.7 lbs/acre average). This was confirmed by the Haney test (Table 31). Based on the Haney test, there were 37.9 lbs of available N in Fallow, of which 33.4 lbs were nitrate N, and 20.2 lbs/acre of available N in CCM, of which 14 lbs were nitrate N (data not shown). Soil organic matter in 0-6 in. was similar in CCM and Fallow and noticeably higher in August than in March 2017 for no apparent reason other than possibly the decomposition of stubble from the 2014-2016 wheat crops (Table 28 & Table 31). Available N was much higher in March than in August as was Solvita CO2-C, and organic C:N ratio. The latter was significantly higher in CCM than in Fallow in August 2017.

Table 31. Barry WSW August Soil Data (Sample date 8/24/2017, sampled depth 6 inches)

CCM CCM CCM CCM Fallow Fallow Fallow Strip 1 Strip 2 Strip 3 LSMEANS Strip 1 Strip 2 LSMEANS Traditional Soil Test Analysis pH 8.0 7.9 7.8 7.9 8.0 7.9 8.0 LOI SOM (%) 2.2 2.2 2.0 2.1 2.3 1.7 1.9 FIA Nitrate N (lb/ac) 14.0 22.0 20.0 18.7b* 37.0 52.0 45.2a Olsen P (lb P2O5/ac) 53.6 51.3 55.0 53.3a* 50.4 47.7 49.9b Amm. Ac. K (lb K2O/ac) 530.0 462.6 496.3 496.3 474.6 479.4 477.1 CEC (meq/100 g) 17.1 17.1 15.2 16.5 17.1 17.3 16.6 Haney pH 7.9 7.7 7.8 7.8 7.8 7.9 7.9 LOI SOM (%) 2.2 2 1.9 2.0 2.1 1.9 2.0 Available N (lb/ac) 16.7 21.7 22.1 20.2 29.8 44.1 37.9 Available P (lb P2O5/ac) 48.4 43.4 54 48.6 51.9 50.5 53.9 Available K (lb K2O/ac) 89.6 73.9 83.4 82.3 73.7 78.9 76.8 Solvita CO2- ppm C 9.3 10.7 8.9 9.6a* 7.1 7.8 7.1b Organic C:N 12.9 12.4 9.7 11.7a* 10.6 9.6 9.1b Soil Health Index 5.17 4.55 4.62 4.7 4.94 4.17 4.5

*Means followed by the same letter are not significant at α = 0.05.

2. Winter Wheat In 2016, wheat yields averaged 16.2 bu/acre with hardly any difference between the section of the field that was “inter-seeded” to yellow sweet clover (Wheat+YSC) and the one that was not (control). Grain protein content was 10.5% in the control and 9.8% in ‘Wheat+YSC’ (Table 27). The low wheat yield reflects continuous wheat cropping, weed pressure (jointed wheatgrass, cheatgrass, etc.), dry conditions in the spring of 2016, and low seeding rate. More data will be available after wheat harvest in 2018.

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c. Barry East half, SW Field (approx. 53 acres)


Cropping system: NT Wheat-Fallow This field was in winter wheat in 2014-2015. Wheat was harvested on 7/24/15. It averaged 22.5 bu/acre. A ten-cover crop species mixture (CCM) was planted in late July at 15.5 lbs/acre on 45 acres (Table 32). An 8-acre strip was left Fallow for comparison purposes (Figure 7). The cover crops were terminated on 3/11/16 with Buccaneer Plus at 1.5 qt/acre + 2,4-D LV6 at 0.5 pt/acre due to weed pressure. Approximately three weeks later (4/2/16), a six-species mix was planted at 38 lbs/acre (Table 32). The cover crop treatment was sprayed on 6/11/16 with Buccaneer Plus at 1.5 qt/acre + 2,4-D LV6 at 0.5 pt/acre to terminate the cover crops and control weeds. It was again sprayed on 8/29/16 with the same herbicide mix plus Banvel at 4 oz/acre. Juniper hard red winter wheat was planted on 9/3/16 with a double disc drill at 35 lbs/acre. An experimental bacterial solution labeled MB906 was sprayed on 10/10/16 at 1.0 ga/acre to control cheatgrass and jointed goatgrass. It was not effective, possibly due to the extremely dry conditions following application. The wheat heads were handpicked from 1.0 sq. meter areas (5 in CCM and 3 in Fallow) in CCM and Fallow strips on 7/17/17 but the whole field was not harvested until 8/27/17. Soil pH averaged 7.8 in 0-6 in. in August 2015 (Table 33). Soil OM averaged 2.3% and available N, P2O5, K2O averaged 38, 34, and 69 lbs/acre with the Haney method, respectively. Total microbial biomass averaged 1280 ng/g and was mostly composed of bacteria and undifferentiated microbes.

Table 33. Barry SW East Half Soil Test Results Summary (Sample depth 6 inches)

Sampling date/Treatment Aug.'15 4/5/2016 8/29/2016 9/6/2017

Whole field CCM Fallow CCM Fallow

CCM Strip #1

CCM Strip #2

CCM Average

Fallow Strip

Traditional (NPK) Analysis (ppm) pH NA NA NA NA NA 7.9 7.8 7.9 7.8 LOI SOM (%) NA 2.0 1.7 2.2 2.2 1.7 1.9 1.8 2.0 FIA Nitrate N (lb/ac) NA 6.1 5.0 21.4 37.8 25.6 25.2 25.4 23.8 Olsen P (lb P2O5/ac) NA 65.2 36.7 54.9 59.4 41.2 53.6 47.4 45.8 Amm. Ac. K (lb K2O/ac) NA 500.9 474.9 468.3 455.3 472.7 500.9 486.8 470.5 CEC (meq/100 g) NA 17.8 16.8 21.2 21.0 17.7 19.4 18.6 18.2 Haney - Soil Health Analysis pH 7.8 7.7 7.6 7.7 7.6 7.9 7.8 7.9 7.9 LOI SOM (%) 2.3 1.6 1.6 2.2 2.2 2.0 2.0 2.0 2.2 Available N (lb/ac) 38.0 11.7 16.0 24.5 37.8 13.3 16.2 14.8 13.6 Available P (lb P2O5/ac) 33.9 48.1 26.6 30.1 29.4 39.1 41.2 40.2 40.9

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Whole field CCM Fallow CCM Fallow

CCM Strip #1

CCM Strip #2

CCM Average

Fallow Strip

Available K (lb K2O/ac) 68.6 74.0 76.7 78.4 89.3 78.2 78.3 78.3 81.6 Solvita CO2- ppm C 17.5 24.2 33.1 8.9 16.1 8.9 12.8 10.9 11.1 Organic C:N 10.1 15.3 14.3 18.4 19.2 12.5 13.6 13.1 14.5 Soil Health Index 4.3 4.2 4.2 2.8 3.0 4.2 4.8 4.5 5.0 PLFA - Soil Community Microbial Analysis Total biomass (ng/g) 1280.0 1506.5 1706.0 2352.6 1360.5 Bacteria (%) 47.9 55.1 52.3 36.2 45.5 Fungi (%) 10.1 8.6 10.5 2.8 2.0 Protozoa (%) 0.0 0.5 0.7 0.0 0.0 Undifferentiated (%) 41.9 35.9 36.4 61.0 52.5 Diversity Index 1.4 1.4 1.6 1.2 1.2

ii. Results

1. Cover crops May through July 2015 was unusually wet in the project area, which led to adequate soil moisture in the seedbed (top 1-2 ft.) at CCM planting on July 29th (Table 34). August-September was below normal while October precipitation was above normal (Table 3 & Table 4). Fall stand was uneven. The first killing frost did not occur until October 27, 2015, which was later than normal. Plant biomass on 10/28/15 averaged 400 lbs DM/acre (Table 35). Canopy cover was 32%. The 29 July-planted CCM was sprayed with Buccaneer Plus and 2, 4-D on March 11, 2016 and a spring CCM was planted on April 2nd. The seedbed was dry at planting and there was little precipitation until late April. May precipitation averaged around 1.6” in Eastland (Table 5) and 0.5” or less in June. Hence, there was not enough time or moisture to produce much biomass from the spring-planted CCM it was terminated on June 11th. The average plant biomass of 562 lbs/acre was mostly from the yellow sweet clover and nitro radish that survived the winter or the herbicide application in March. Cover crops were present in the order: Yellow Sweet Clover (43%) > Turnip (31%) > Flax (12%) > Spring pea (12%) > Oat-barley (6%). No rapeseed or safflower was a “hit” with the line-transect method.

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Table 34. 2016 On-Farm Trial Gravimetric Soil Moisture Results

Soil moisture average by weight (%)

Field condition Treatment Fallow Fallow CCM CCM

Soil depth 0-12 in. 12-24 in. 0-12 in. 12-24 in.

Crowley 18.6 17.8 17.0 16.7 Post CCM, Pre-Safflower

Lewis 12.7 12.8 17.8 12.7 Post Wheat, Pre-CCM

Garchar* 6.9 8.4 7.9 10.3 Post CCM, Pre-CCM

Barry SW 12.0 13.6 8.5 10.1 Post CCM, Pre-Wheat

Barry N 13.4 14.7 9.0 9.5 Post CCM, Pre-Wheat * Garchar field had a solid stand of volunteer wheat in the fallow strips.

Table 35. Plant Data at Barry ESW in 2015 & 2016

10/28/2015 6/10/2016

Average Transect

#1 Transect

#2 Transect

#3 2016

Average Plant Biomass (lbs/acre) 400 463 378 846 562 Canopy Cover (%) 32.0 56.0 30.0 34.0 40.0

Cover crop NA 54.0 26.0 28.0 36.0 Volunteer wheat NA 0.0 0.0 0.0 0.0

Weeds NA 2.0 4.0 6.0 4.0 Ground Cover (%) 81.3 70.0 94.0 76.0 80.3

Bare ground 18.7 30.0 6.0 24.0 19.7 Cover crop 20.0 4.0 4.0 4.0 8.0

Residue 27.3 42.0 88.0 68.0 56.3 Stubble 14.0 0.0 0.0 2.0 4.0

Volunteer wheat 13.3 6.0 0.0 0.0 4.8 Weeds 6.7 18.0 2.0 2.0 7.2

Cover Crop Species Presence (%) Spring pea NA 3.7 23.0 7.1 11.3

Oat NA 0.0 0.0 0.0 0.0 Barley* NA 11.1 0.0 7.1 6.1

Rapeseed NA 0.0 0.0 0.0 0.0 Safflower NA 0.0 0.0 0.0 0.0

Flax NA 7.4 15.3 14.2 12.3 Turnip NA 37.0 34.8 21.4 31.1

Yellow sweet clover NA 55.5 23.0 42.8 40.4 *We may have counted some of the oat as barley.

Soil N was low in the spring of 2016 before CCM planting and higher in the summer before wheat planting (Table 33). It averaged 38 lbs/acre in Fallow and 21 to 24 lbs/acre in CCM, depending on the extraction method. Interestingly, FIA

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Nitrate N and available N (Haney) were similar in August. Soil OM dropped to 1.6% in April 2016 from 2.3% in August 2015, and then went back up to 2.2% in August 2016. This may be an anomaly since the traditional soil test analysis did not show as much variation in SOM as Haney did. Both tests used the same soil samples and method to determine SOM. With the exception of N and Solvita CO2-C, there were no noticeable differences in soil test results between CCM and Fallow. In contrast, microbial biomass was markedly higher in CCM than in Fallow in August 2016 (Table 33). This difference may or may not be significant since there was only one Fallow strip.

2. Winter wheat (2017) Wheat averaged 28.9 bu/acre, with the fallow strip outperforming the CCM strips by 7.3 bu/A (Table 32). Grain protein was slightly higher in CCM (15.0%) than in Fallow (14.1%). The difference in wheat appearance between the Fallow and CCM strips was apparent in the field as wheat in Fallow was generally taller and earlier maturing than wheat in CCM. The higher wheat yield in Fallow is likely due to more soil moisture and available N at planting. Water content (by weight) in the top 2.0 ft. of soil averaged 9% in CCM and 13% in Fallow in late August 2016 (Data not shown). Nitrate N in 0-6 in. averaged 21 lbs/acre in CCM and 38 lbs/acre in Fallow (Table 33). These differences disappeared after wheat harvest in 2017, except for SOM, which appeared to be higher in Fallow than in CCM. The soil was extremely dry prior to CCM planting, regardless of the treatment.

d. Barry North (approx. 47 acres)


This field was in winter wheat in 2014-2015. Wheat was harvested on 7/24/15. It averaged 10 bu/acre, probably due to a large infestation of cheatgrass and jointed wheatgrass, and low seeding rate. A 10-cover crop species mixture (CCM) was planted on 7/31/15 at 15.5 lbs/acre with a hoe drill on approximately 40 acres (Table 36). Two strips totaling 7.0 acres were left fallow for comparison (Figure 8). The cover crops were sprayed on 3/11/16 with Buccaneer Plus at 1.5 qt/acre and 2,4-D LV6 at 0.5 pt/acre due to weed pressure and on 4/2/16, a six-species CCM was planted at 15.5 lbs/acre in the same strips as in 2015. The cover crop strip was sprayed on 6/11/16 with Buccaneer and 2,4-D to terminate the cover crops and control weeds. It was again sprayed on 8/22/16 and Juniper hard red winter wheat was planted on 9/3/16 with a double disk drill at 30 lbs/acre. The whole field was sprayed with an experimental bacterial solution on 10/10/16 at 1.0 ga/acre to control cheatgrass and jointed goat grass. This treatment was not effective, possibly due to the extremely dry conditions following application. We took one square meter wheat samples (3 to 5 samples in the cover crop and 2 to 4 samples in the fallow) from the CCM and Fallow strips on 7/19/17 but the whole field was not harvested until 8/27/17. It was then sprayed with 2,4-D LV6 at 0.33 pts/acre on 9/12/17 and a four-species CCM was drilled at 21 lbs/acre on 9/17/17.

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The soil test results in 2015, 2016, and 2017 are shown in Table 36. The SOM of 3.0% in August 2015 is much higher than in 2016 and 2017 and may not be accurate. Available N as measured with the Haney method averaged 28.8 lbs/acre, available P 37.8 lbs P2O5/acre, and available K 73.5 K2O/acre. Soil health index was 4.3 in August 2015 compared to 3.2 in April 2016. Soil pH was around 7.7 at both sampling dates but available N was much lower in April 2016 than in August 2015. There were also variations in available P and K. For example, CCM had more available P in CCM (58 lbs P2O5/acre) than in Fallow (40 lbs/acre) but the difference was not significant and may be due to inherent variability in soil type or fertility since CCM and Fallow were managed similarly prior to CCM planting.

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Table 37. Barry North Soil Test Results Summary (Sample depth 6 inches)


Whole Filed CCM Fallow CCM Fallow CCM

Strip #1 CCM

Strip #2 CCM

Average Fallow

Strip #1 Fallow

Strip #2 Fallow

Average Traditional (NPK) Analysis (ppm) pH NA NA NA NA NA 7.8 8.0 7.9 7.8 8.0 7.9 LOI SOM (%) NA 1.8 1.6 1.9 1.9 2.0 1.9 2.0 1.6 1.8 1.7 FIA Nitrate N (lb/ac) NA 5.4 5.0 17.8 32.9 7.9 7.6 7.7 5.6 5.9 5.8 Olsen P (lb P2O5/ac) NA 62.7 50.7 59.0 60.2 41.2 40.4 40.8 39.6 48.7 44.1 Amm. Ac. K (lb K2O/ac) NA 568.1 513.9 537.7 548.6 448.8 472.7 460.8 487.9 422.8 455.3 CEC (meq/100 g) NA 16.5 16.4 17.6 17.4 18.5 16.4 17.5 15.2 16.3 15.8 Haney - Soil Health Analysis pH 7.7 7.8 7.7 7.8 7.5 7.4 8.0 7.7 7.3 8.0 7.7 LOI SOM (%) 3.0 1.5 1.3 1.9 1.9 1.8 1.8 1.8 1.6 1.8 1.7 Available N (lb/ac) 28.8 8.6 10.2 19.3 34.2 13.1 14.9 14.0 12.5 12.6 12.6 Available P (lb P2O5/ac) 37.8 57.9 40.0 34.1 33.7 41.9 47.7 44.8 46.6 41.3 44.0 Available K (lb K2O/ac) 73.5 89.6 92.7 100.2 105.6 69.6 80.3 75.0 87.6 76.0 81.8 Solvita CO2- ppm C 15.4 12.2 13.5 4.7 4.5 7.8 8.1 8.0 6.5 7.1 6.8 Organic C:N 12.4 15.4 13.2 13.8 10.3 15.1 12.7 13.9 12.5 14.2 13.4 Soil Health Index 4.3 3.2 3.0 2.2 2.4 3.7 3.9 3.8 3.3 3.6 3.5 PLFA - Soil Community Microbial Analysis Total biomass (ng/g) 2427.4 1559.8 1078.3 1315.5 2978.0 Bacteria (%) 45.0 45.0 41.7 43.7 28.9 Fungi (%) 11.9 12.0 8.1 9.8 8.3 Protozoa (%) 1.2 0.6 0.0 0.0 0.2 Undifferentiated (%) 44.9 42.4 50.2 46.5 62.7 Diversity Index 1.6 1.6 1.5 1.4 1.4

There were also apparent but not significant differences in microbial biomass between CCM (1560 ng/g) and Fallow (1078 ng/g).

i. Results

1. CovercropsMay through July 2015 was unusually wet in the project area, which led to adequate soil moisture in the seedbed at CCM planting in late July. August-September was below normal while October precipitation was above normal (Table 3). The first killing frost did not occur until October 27, 2015, which was later than normal. Plant dry matter on 10/28/15 averaged 970 lbs/acre, which was more than twice the amount of biomass at Barry ESW (Table ). Canopy cover was 44%. Early planting, a longer than usual fall growing season, and the inclusion of warm season species such as sorghum sudangrass, sunflower, and buckwheat in the cover crop mix may explain the “respectable” amount of plant biomass produced before winter kill. More biomass was produced in the spring of 2016. It averaged 1527 lb/acre on 6/10/2016, which was 2.7 times the biomass produced at Barry ESW. Canopy cover was 75 %, of which 67% were cover crops and 7% weeds. Most of the biomass was from the yellow sweet clover and turnip that survived the winter and the herbicide application in March. Yellow sweet clover was encountered in the plant canopy (with the line-transect method) 37% of the time and turnip 34%. Among the spring-planted cover crops, barley or oat was encountered 31% of the time, flax 11%, and spring pea 9%. There was also black medic (4% hit) from a 2014 cover crop planting. The spring-planted cover crops had a decent stand but did not produce much biomass. Plant biomass was substantially lower in Barry East SW field than in Barry North, although both fields were managed similarly. Differences could be due to soil type and topography, weed pressure, precipitation amount, etc.

Table 38. Plant Data at Barry North

10/28/2015 6/10/2016

Average

Transect #1

Transect #2

Transect #3

Average

Plant Biomass (lbs/acre) 969.6 1510.0 1960.0 1110.0 1526.7

Canopy Cover (%) 44.0 78.0 80.0 66.0 74.7

Cover crop NA 68.0 72.0 62.0 67.3

Volunteer wheat NA 0.0 0.0 0.0 0.0

Weeds NA 10.0 8.0 4.0 7.3

Ground Cover (%) 82.0 46.0 42.0 46.0 44.7

Bare Ground 18.0 54.0 58.0 54.0 55.3

Cover crop 24.7 10.0 2.0 2.0 4.7

Residue 21.3 34.0 40.0 44.0 39.3

Stubble 5.3 0.0 0.0 0.0 0.0

Volunteer wheat 26.0 0.0 0.0 0.0 0.0

Weeds 4.7 2.0 0.0 0.0 0.7

40

41

10/28/2015 6/10/2016

Average Transect #1

Transect #2

Transect #3 Average

Cover Crop Species Presence (% present) Spring pea NA 5.8 16.6 3.2 8.5

Oat NA 0.0 0.0 0.0 0.0 Barley* NA 35.2 33.3 25.8 31.4

Rapeseed NA 0.0 0.0 0.0 0.0 Safflower NA 2.9 0.0 3.2 2.0

Flax NA 11.7 11.0 9.6 10.8 Turnip NA 20.5 30.5 51.6 34.2

Yellow sweet clover NA 47.0 36.1 29.0 37.4 *We may have counted some of the oat as barley.

2. Winter wheat Wheat yield was higher in Fallow (32.5 bu/acre) than in CCM (24.2 bu/acre) but the difference was not significant (Table 36). Grain protein content was slightly higher in CCM (12.2%) than in Fallow (11.6%). The higher wheat yield in Fallow may be due to more available soil moisture and N at planting. Soil moisture on 8/31/16 was at or below the wilting point in CCM (9% by weight) and 14% in Fallow. Moreover, precipitation in the spring of 2017 was below normal. Available N shortly before wheat planting in 2016 was greater in Fallow (34 lbs N/acre) than in CCM (19 lbs N/acre). Soil OM averaged 1.9% in both the Fallow and CCM strips, which is greater than what was measured in the spring (1.5%). Microbial biomass was more than twice in Fallow (2978 ng/g) than in CCM (1315 ng/g) but the difference may or may not be significant (Table 37). Soil test results after wheat harvest and prior to cover planting in September 2017 shows a substantial decrease in available N and a drop in P and K, compared to late August 2016 (Table 37). Soil OM averaged 1.7 in Fallow and 2.0 in CCM but the difference was not significant.

e. Crowley-Nebeker (approx. 29 acres)


Crop rotation: winter wheat-safflower-fallow Management system: certified organic with conventional tillage Cropping history and field operations: The 2014-2015 winter wheat crop averaged 34.3 bu/acre. The whole field was disked once in late August and a six-species cover crop mixture (CCM) was planted on 9/10/15 at 25 lbs/acre with a double disc drill on approximately 20 acres (Table 39). The rest of the field (approx. 9.0 acres) was left fallow for comparison purposes (Figure 9 in Appendix B). The CCM was terminated on 4/22/16 with a field cultivator equipped with points and an attached harrow. The

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whole field was again cultivated on 5/12/16. Safflower was planted on 5/17/16 at 15 lbs/acre and it was harvested in mid-November. A seven-species cover crop mixture was planted on 4/14/17 at 18.21lbs/acre on the same 20 acres as the previous CCM. It was terminated on 6/20/17 with one pass of a field cultivator with sweeps. The whole field was then worked twice before planting Curlew HRWW on 10/6/17 at 60 lbs/acre. The Haney soil test results prior to CCM planting in September 2015 show a pH of 7.3, SOM of 1.6%, and low available N (Table 40). Available N and nitrate N remained low though 2017. Available P was markedly lower in Fallow than in CCM in the spring of 2016 and 2017 and in September 2017 but the difference was narrower with the traditional soil test analysis than with the Haney. Potassium as measured with the ammonium acetate extraction method was plentiful.

Table 40. Crowley Soil Test Result Summaries (Sample depth 6 inches)

Sampling date/Treatment

Summer 2015 Spring 2016 Spring (4/11/2017) Summer (9/1/2017)

Whole field CCM Fallow CCM Fallow CCM Fallow Traditional (NPK) Analysis pH NA NA NA 7.5 7.8 7.5 8.0 LOI SOM (%) NA 1.3 1.3 1.6 1.5 1.5 1.4 FIA Nitrate N (lb/ac) NA 2.9 2.9 2.3 1.8 8.5 12.6 Olsen P (lb P2O5/ac) NA 48.7 32.6 56.1 41.7 42.5 35.5 Amm. Ac. K (lb K2O/ac) NA 455.3 468.3 535.6 472.7 470.5 403.3 CEC (meq/100 g) NA 13.8 16.5 13.7 17.2 13.0 16.6 Haney - Soil Health Analysis pH 7.3 7.2 7.3 7.4 7.7 7.7 7.9 LOI SOM (%) 1.6 1.1 1.0 1.7 1.5 1.5 1.6 Available N (lb/ac) 4.0 9.5 7.7 16.3 6.4 16 15.8 Available P (lb P2O5/ac) 21.9 27.9 13.4 44.1 23.2 51.2 27.6 Available K (lb K2O/ac) 81.6 85.5 73.5 147.6 102.9 100.8 69.1 Solvita CO2- ppm C 9.7 12.8 12.8 16.1 11.7 13.5 9.7 Organic C:N 15.0 12.8 14.2 11.4 13.9 10.9 11.6 Soil Health Index 1.9 2.6 2.4 2.9 2.1 4.4 3.5 PLFA - Soil Community Microbial Analysis Total biomass (ng/g) 1459.2 1607.1 1379.0 2188.3 1060.2 NA NA Bacteria (%) 42.0 50.6 54.2 35.3 47.7 NA NA Fungi (%) 13.9 4.5 12.7 11.6 17.9 NA NA Protozoa (%) 0.1 0.0 0.5 0.4 0.0 NA NA Undifferentiated (%) 44.0 44.9 32.5 52.7 34.4 NA NA Diversity Index 1.6 1.2 1.5 1.5 1.6 NA NA

ii. Results

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1. Cover crops The CCM that was planted on 9/10/15 had a very poor stand due to low soil moisture and poor seed-soil contact. The latter was due to the uneven and large amount of wheat stubble, which made it difficult to plant cover crops with a conventional (double disc) drill. The farm manager was not able to work the ground more than once before planting the cover crops. Moreover, there was little plant growth in the spring before the CCM was terminated on April 22, 2016. Consequently, plant biomass averaged 3.5 lbs/acre. The second CCM that was planted in mid-April 2017 had a better stand due to more moisture at planting (17% by weight in the top 2.0 ft.) and better seed-soil contact. Total plant biomass averaged 242 lbs DM/acre to which barley contributed 46%, spring pea 18%, safflower 15%, nitro radish 14%, and forage collards 4% (Table 41). Crimson clover contributed only 2.1%, despite representing 34% of the seeds in the mixture. Sunn hemp and sunflower contributed less than 0.5% to plant biomass while proso millet was not even present in the line-transects. These and other warm-season plants may not germinate when soil temperature is below 50 deg. F. Canopy cover averaged 35% of which cover crops represented 31%. Barley was encountered along the line-transects 10.7% of the time, radish 8.7%, spring pea 4.7%, and the other species 2% or less. Plant biomass of the spring 2017 planted cover crops was substantially less than at Barry Middle (681 lbs/acre) or Barry West SW (704 lbs/acre). Crowley’s CCM was planted one day later (4/14/17) than Barry’s, but this would not explain the large difference in plant biomass between the two locations. Other factors may be at play such as precipitation, soil moisture, and soil fertility. No-till soil management may have contributed to more water in the top 2.0 ft. of soil (by a couple % points) at Barry’s than at Crowley’s at CCM planting. Having safflower in the crop rotation at Crowley’s may have also led to a drier soil profile at CCM planting, due to the late harvest date of safflower and its deep roots, compared to winter wheat.

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Table 41. Plant Biomass and Canopy Cover at Crowley (Sample date 6/15/2017)

Plant Dry Matter (lbs/ac) CCM Species Presence

(%)* Plant species Transect 1 Transect 2 Transect 3 Average % of total Spring pea 19.0 83.6 28.2 43.6 18.0 4.7

Radish 92.8 8.4 0.0 33.7 13.9 8.7 Barley 232.2 23.2 78.6 111.3 45.9 10.7

Sunn hemp 0.0 1.6 0.0 0.5 0.2 1.3 Forage collards 14.6 9.6 4.6 9.6 4.0 1.3 Crimson clover 1.8 13.4 0.0 5.1 2.1 0.7

Sunflower 0.0 0.0 1.4 0.5 0.2 2.0 Safflower 108.6 0.0 2.6 37.1 15.3 2.0

Weeds 0.0 0.0 3.0 1.0 0.4 NA Total 469 140 118 242.4 100.0 % Cover Canopy Cover 36.0 36.0 32.0 34.7

Cover crop 32.0 30.0 32.0 31.3 Volunteer wheat 0.0 0.0 0.0 0.0

Weeds 4.0 6.0 0.0 3.3 Ground Cover 34.0 52.0 50.0 45.3

Bare ground 66.0 48.0 50.0 54.7 Cover crop 8.0 4.0 2.0 4.7

Residue 26.0 48.0 48.0 40.7 Stubble 0.0 0.0 0.0 0.0

Volunteer wheat 0.0 0.0 0.0 0.0 Weeds 0.0 0.0 0.0 0.0

*Average of three measurements

2. Cash Crops Safflower in Fallow outperformed safflower in CCM but no statistical test could be performed.

Table 42. Safflower yield at Crowley’s in 2016

Treatment Seed yield (lbs/acre)

Seed oil content (%)

Seed test weight (lbs/bu)

Seed water content (%)

CCM (20 acres) 763.0 35.5 38.5 6.0 Fallow (9 acres) 898.0 35.1 39.5 6.4 Safflower was planted on 5/17 and harvested on 11/15/16.

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The second cash crop, winter wheat, was planted on 10/6/2017 and will be harvested by early August 2018. The seedbed at planting was very dry and there was little precipitation in the fall of 2017.

f. Garchar (approx. 40 acres)


Crop rotation: TBD Soil management: conventional tillage (CT) Field operations: The field was in winter wheat in 2014-2015. It was sprayed with Roundup at 1 qt/acre on 4/6/16 and planted to a spring cover crop mixture on 4/22/16 at 15 lbs/acre. Three strips were planted to CCM and three strips were left fallow (Figure 10 in Appendix B). CCM consisted of FIXatioN Balansa Clover (43% by weight), Frosty Berseem Clover (16.6%), Crimson Clover (13.3%), Annual Ryegrass (20%), and Driller Daikon Radish (6.6%). The original mix developed by Poudre Valley COOP in Ft. Collins had less Balansa clover (40%) and more Daikon radish (10%) and annual ryegrass (30%), and no crimson clover. The CCM was terminated on 7/6/16 with one pass of a tandem disk. The cooperator had plans to plant the whole field to winter wheat in the fall of 2016 but decided instead to try a second CCM from seeds he had or could purchase locally (Table 43). He planted this CCM on 8/23/16 at 34.5 lbs/ac. The first killing frost occurred on 10/21/16. The whole field was sprayed with Roundup at 2 qts/acre on 5/15/17 and disked on 5/29/17. The cooperator thought about planting safflower, sunflower or dry bean in the whole field but was unable to do so due to time constraints and ended up planting a third CCM on 8/26/17 at 39 lbs/acre (Table 43). Soil OM averaged around 1.7 to 1.9%, except in the spring of 2016 where both the traditional soil test analysis and Haney showed SOM of 1.3 to 1.5% (Table 44). The reason for this discrepancy is not known. Soil N was low throughout the trial period, except in the spring of 2016 in Fallow where nitrate N averaged 34 lb/acre, which may be an aberration or the result of an error or contamination. Microbial mass values appear to favor CCM but there was no significant difference between CCM and Fallow in May 2017 (Table 44). The PFLA data for the spring and summer of 2016 was from composite samples for each of the two treatments, CCM and Fallow. Hence, we could not do the statistical analysis for those two sampling dates.

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Table 44. Garchar Soil Test Results (Sample depth 6 inches)

Summer

2015 Spring 2016 Fall 2016 5/25/2017 8/9/2017

Whole field CCM Fallow CCM Fallow CCM Fallow CCM Fallow

Traditional (NPK) Analysis pH NA NA NA NA NA 7.8 7.6 7.8 8.0 LOI SOM (%) NA 1.5 1.5 1.9 1.7 1.8 1.7 1.7 1.8 FIA Nitrate N (lb/ac) NA 2.2 34.0 5.6 3.1 1.4 0.9 19.2 16.4 Olsen P (lb P2O5/ac) NA 51.1 78.0 86.6 74.2 53.2 47.2 59.7 58.4 Amm. Ac. K (lb K2O/ac) NA 529.1 472.7 479.2 470.5 434.4 419.9 480.6 462.6 CEC (meq/100 g) NA 19.9 16.4 16.2 17.9 15.9 16.6 16.2 16.6 Haney - Soil Health Analysis pH 7.6 7.5 7.5 7.7 7.5 7.8 7.7 7.8 7.9 LOI SOM (%) 1.8 1.5 1.3 1.9 1.7 1.9 1.8 1.7 1.8 Available N (lb/ac) 9.6 8.0 4.5 12.6 8.1 5.2 4.3 12.8 12.3 Available P (lb P2O5/ac) 56.1 24.2 36 58.4 43 44.9 39.6 54.2 55.1 Available K (lb K2O/ac) 105.5 73.3 78.3 94.6 79.9 84.1 76.8 86.4 82.6 Solvita CO2- ppm C 8.5 26.4 9.7 5.2 5.2 9.5 9.4 9.7 8.8 Organic C:N 11.3 18.1 18.3 20.3 25.5 18.2 20.1 12.0 12.5 Soil Health Index 2.18 3.43 2.3 1.72 1.52 2.0 1.9 3.4 3.3 PLFA - Soil Community Microbial Analysis Total biomass (ng/g) 2610.3 1645.7 1353.6 1315.9 992.0 1924.4 1430.2 Bacteria (%) 32.7 48.2 45.4 46.0 44.4 40.7 46.2 Fungi (%) 14.4 7.9 4.4 2.3 2.5 12.1 16.0 Protozoa (%) 0.1 0.0 0.0 0.0 0.0 0.2 0.1 Undifferentiated (%) 60.1 44.0 50.2 51.7 53.1 47.0 37.7 Diversity Index 1.4 1.3 1.3 1.2 1.2 1.5 1.5

ii. Results

1. Cover Crops The April 2016 planted CCM averaged 49.5 lbs DM/acre (Table 45). The seedbed was dry at planting due to poor weed management and low winter precipitation. April precipitation was below normal and June’s was above normal. Canopy cover was 48%, 7% of which was from CCM. Volunteer wheat and weeds made up the other 41% of the canopy. Over 80% of the basal canopy was bare ground. Annual ryegrass was encountered along the line transect 8% of the time, Daikon radish 29%, and crimson clover 29%. No balansa clover was present. The second CCM was planted late (8/23/2016) and literally within minutes of a significant rain event (≥0.66”). Precipitation in September was below normal. October was Dry. The first frost occurred on 10/03/2016 and was followed by a hard freeze on 10/21/2016. Plant biomass averaged 177 lbs/acre (Table 45). Oats

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were present 16% of the time, barley 19%, sorghum sudangrass 6%, maple peas 1%, yellow peas 1%, and sunflower less than 1%. No corn or bean plants were encountered in the line-transects, possibly because they were killed by the first fall frost. The August 2016 planted CCM had a good stand but there was not much biomass (177 lbs/acre) when the first fall frost hit in early October. The expectation is that winter pea, winter triticale, and hairy vetch will survive the winter and resume growth in the spring of 2018. Corn was included in the mixture (Table 43) at the cooperator’s request but because of the late planting date and early frost, its contribution to soil health will probably be negligible.

2. Cash Crop No cash crop was planted in 2016 or 2017. The hope is to plant winter wheat in 2018.

g. Lewis (approx. 46 acres)


Crop rotation: Wheat-Fallow Soil Management: Conventional tillage (CT) Field operations: Before the start of this project, a large portion (approx. 29 acres) of the field was planted to an eight-species cover crop mixture (CCM). The rest of the field (approx. 17 acres) was left fallow (Table 46). The CCM was planted on 8/30/14 and was sprayed on 4/15/15 with Buccaneer Plus at 1 qt/acre and 2,4-D LV6 at 0.5 pt/acre. The whole field was sprayed three more times with the same herbicide formulation to control weeds. Field bindweed was and is still and issue in this field. Urea was applied on 8/30/15 at 80 lbs/acre and winter wheat was planted on 9/10/15 and harvested on 8/15/16. The whole field was disked twice on 11/15/16 and a seven-species CCM was planted on 12/6/16 at 20.3lbs/acre (Figure 11 in Appendix B). The whole field was moldboard plowed on 5/16/17, then worked with a field cultivator. It was sprayed with Tordon+2,4-D on 8/15/17. Pig manure was applied to Fallow only on 9/25/17 and the whole field was planted to Juniper HRWW at 45 lbs/acre on 9/26/17.

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Table 45. Garchar Plant Data for 2016

6/17/2016 10/17/2016 Transect 1 Transect 2 Transect 3 Average Transect 1 Transect 2 Transect 3 Average Plant DM (lb/ac) 27.5 66.0 55.0 49.5 70.0 390.0 70.0 176.7 Canopy Cover (%) 40.0 50.0 54.0 48.0 62.0 58.0 52.0 57.3

Cover crop 16.0 4.0 0.0 6.7 58.0 42.0 28.0 42.7 Volunteer wheat 8.0 36.0 18.0 20.7 0.0 0.0 0.0 0.0

Weeds 16.0 10.0 36.0 20.7 4.0 16.0 24.0 14.7 Ground Cover (%) 12.0 12.0 16.0 13.3 22.0 22.0 32.0 25.3

Bare ground 88.0 88.0 84.0 86.7 78.0 78.0 68.0 74.7 Cover crop 8.0 0.0 0.0 2.7 0.0 0.0 0.0 0.0

Residue 2.0 0.0 0.0 0.7 20.0 22.0 32.0 24.7 Stubble 0.0 0.0 2.0 0.7 0.0 0.0 0.0 0.0

Volunteer wheat 2.0 10.0 4.0 5.3 0.0 0.0 0.0 0.0 Weeds 0.0 2.0 10.0 4.0 2.0 0.0 0.0 0.7

Cover Crop Species % time present Average

Cover Crop Species % time present Average

Radish 37.5 50.0 0.0 29.2 Oats 28.0 16.0 4.0 16.0 Balansa clover 0.0 0.0 0.0 0.0 Barley 18.0 20.0 20.0 19.3 Crimson clover 37.5 50.0 0.0 29.2 SSG* 14.0 4.0 2.0 6.7

Ryegrass 25.0 0.0 0.0 8.3 Maple peas 2.0 2.0 0.0 1.3 *SSG: Sorghum Sudan Grass Yellow peas 0.0 0.0 4.0 1.3 Sunflower 2.0 0.0 0.0 0.7

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Soil OM in 0-6 in. was 2.3% in September2015 and available N was 53.4 lbs/acre (Table 47). Lower values were measured in the fall of 2016. SOM appears to be lower in Fallow than in CCM in the fall of 2016. The reverse was true in 2017. Potassium was markedly higher in Fallow than in CCM in the fall of 2016 as was CEC. Solivita CO2-C averaged 17.5 ppm in 2015 and 10 ppm or less afterwards. There were also variations in organic C/N, soil health index, and available P and N. Microbial biomass was numerically greater in Fallow than in CCM in 2016 and 2017 (Table 47). No conclusions or inferences could be drawn from the soil test results at this writing.

Table 47. Lewis Soil Results Data (Sample depth 6 inches)

Summer 2015 Fall 2016 9/14/2017 Whole field CCM Fallow CCM Fallow Traditional (NPK) Analysis pH NA NA NA 8.1 8.0 LOI SOM (%) NA 1.5 1.2 1.9 2.3 FIA Nitrate N (lb/ac) NA 6.1 5.6 26.5 28.4 Olsen P (lb P2O5/ac) NA 40.4 31.8 38.4 35.9 Amm. Ac. K (lb K2O/ac) NA 58.5 340.4 665.7 520.4 CEC (meq/100 g) NA 3.5 14.8 27.4 27.1 Haney - Soil Health Analysis pH 7.8 8.0 7.1 8.0 7.9 LOI SOM (%) 2.3 1.7 1.5 2.1 2.3 Available N (lb/ac) 53.4 21.2 12.6 24.7 26.9 Available P (lb P2O5/ac) 19.3 9.1 9.7 10.7 13.9 Available K (lb K2O/ac) 126.4 96.5 142.7 89.1 85.0 Solvita CO2- ppm C 17.5 5.7 6.8 8.1 10.2 Organic C:N 9.0 20.1 19.8 9.8 10.0 Soil Health Index 4.4 2.5 1.5 4.8 5.7 PLFA - Soil Community Microbial Analysis (May 2017) Total biomass 1110.6 777.2 1143.1 1687.0 2006.2 Bacteria 44.4 39.5 28.2 51.0 49.8 Fungi 11.9 1.8 1.7 15.8 16.0 Protozoa 0.3 0.0 0.0 0.8 0.8 Undifferentiated 43.5 58.7 70.1 32.4 33.4 Diversity Index 1.5 1.2 1.2 1.6 1.6

ii. Results

1. Cover Crops No data is available from the August 2014-planted CCM. The second CCM was planted much later (12/6/16) than expected (Table 48). Moreover, there was a large infestation of field bindweed, which prompted the cooperator to terminate CCM early. Hence, several of the cover crop species did not germinate or grow

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much. Total plant biomass averaged 498 lbs/acre, 90% of which was from volunteer wheat (Table 48). There were negligible amounts of sanfoin and yellow sweet clover (<2 lb/acre each) and not much else besides volunteer wheat.

Table 48. Lewis Plant Biomass & Canopy Cover (Sample date 5/15/2017)

Transect 1 Transect 2 Transect 3 Average % of Total

Biomass Plant Dry Matter (lbs/acre) Volunteer wheat 290.0 640.0 410.0 446.7 0.9

Weeds 114.2 18.4 14.0 48.9 0.1 Yellow sweet clover 0.0 0.0 2.4 0.8 0.0

Sainfoin 0.0 2.4 2.6 1.7 0.0 Total 404.2 660.8 429.0 498.0 1.0

Canopy Cover (%) 12.0 16.0 28.0 18.7 Cover crop 2.0 2.0 4.0 2.7

Volunteer wheat 10.0 14.0 22.0 15.3 weeds 0.0 0.0 2.0 0.7

Ground Cover (%) 50.00 68.00 52.00 56.7 Bare ground 50.0 32.0 48.0 43.3

Cover crop 0.0 0.0 0.0 0.0 Residue 50.0 68.0 52.0 56.7 Stubble 0.0 0.0 0.0 0.0

Volunteer wheat 0.0 0.0 0.0 0.0 Weeds 0.0 0.0 0.0 0.0

Cover Crop Species % presence Sainfoin 2.0 0.0 1.0 1.0

Yellow sweet clover 0.0 2.0 1.0 1.0 Cowpeas 0.0 0.0 0.0 0.0

Pearl millet 0.0 0.0 0.0 0.0 Tillage radish 0.0 0.0 0.0 0.0

Flax 0.0 0.0 0.0 0.0 Purple top turnip 0.0 0.0 0.0 0.0

2. Cash Crop In 2016, winter wheat following CCM outperformed winter wheat in Fallow by 20.4 bu/acre (60.8 vs. 40.4 bu/acre), based on our estimates (Table 46) from five 1.0 sq. meter samples in CCM and five samples in Fallow. Conversely, grain protein was higher in Fallow (16.6%) than in CCM (15.1%). The cooperator reported a much lower wheat yield of 37 bu/acre for the entire field. Consequently, our estimates may not be accurate. Any difference in wheat yield or protein concentration between CCM and Fallow may or may not be due to cover crops since there was no replication.

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h. Waschke (approx. 66 acres)

i. Test information (Table 49 in Appendix A, Figure 12 in Appendix B)

Crop rotation: Wheat-Safflower-Fallow? Management system: Conventional tillage (CT), organic Field operations: see information in Table 49.

1. Results In August 2016, wheat yield averaged 8.8 bu/acre in the whole field, with wheat following Austrian pea outperforming wheat after fallow by 3.4 bu/a (Table 49). Grain protein was also higher in the cover crop than in the fallow treatment. These differences may or may not significant. No other useful data was collected from this demonstration trial. The cooperator withdrew from the project in 2016.

4. Soil Water Infiltration Infiltration rates ranged from 0.24 to 1.17 in/hr in 2016 and 0.62 to 1.20 in/hr in 2017 (Table 50). In comparison, a CRP field in Dolores County had an infiltration rate of 0.62 in/hr. Infiltration appears to be similar or higher in Fallow than in CCM in 2016, except at SWCRC#1. In the latter, infiltration in CCM #1 was significantly higher than in Fallow at P=87%. The same was true with the steady-state infiltration rate, which was significantly higher in CCM #1 and CCM #2 than in Fallow. Steady-state infiltration normally occurs when the soil is nearly saturated. If this trend continues, it would indicate that cover crops increased the infiltration rate at SWCRC#1. This was not the case at SWCRC#2 in 2017 (Table 50). However, No-Till (NT) averaged 0.69 in/hr at the steady state compared to 0.37 in/hr with Conventional Tillage (CT). There was a lot of variation in the average infiltration rate (CV of 55%) and the steady-state infiltration rate (CV of 98%) at SWCRC #2. Sorptivity was less variable (CV of 16%) and significantly higher in NT (2.18 in/hr^0.5) than in CT (1.66 in/hr^0.5). Sorptivity measures soil’s capacity to absorb or desorb water. Shaver et al. (2013) showed that “increasing crop residue accumulation will have the indirect effect of increased sorptivity via improvements in soil aggregation, bulk density, and porosity that are conducive to water infiltration”. Cover crops should have similar effects to NT through the accumulation of crop residue and organic matter over time. Additional benefits may accrue from crop roots. Several other studies in the Central Great Plains show that NT conserves water, which has led to crop intensification. Shaver, T.M., G.A. Peterson, L.R. Ahuja, and D.J. Westfall. 2013. Soil sorptivity enhancement with crop residue accumulation in semi-arid dryland no-till agroecosystems. Geoderma 192 (2103): 254-258.

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Table 49. Soil infiltration rates in 2016 and 2017

2016 2017

Field/Treatment Infiltration rate

Steady-state

infiltration rate

Sorptivity Infiltration rate

Steady-state

infiltration rate

Sorptivity

in/hr in/hr in/hr^0.5 in/hr in/hr in/hr^0.5 Barry North CC 0.263 0.422 0.835 Wheat Wheat Wheat Barry North Fallow 0.359 0.522 0.971 Wheat Wheat Wheat Barry ESW CC 0.4 0.412 1.022 Wheat Wheat Wheat Barry ESW Fallow 0.61 0.777 0.989 Wheat Wheat Wheat Barry Middle CC Wheat Wheat Wheat 0.634 0.735 1.304 Barry Middle Fallow Wheat Wheat Wheat 0.644 0.563 1.661 Barry WSW CC Wheat Wheat Wheat 0.745 0.723 1.743 Barr WSW Fallow Wheat Wheat Wheat 0.76 0.966 1.318 Crowley CC 0.32 0.454 1.098 0.788 0.519 1.667 Crowley Fallow 0.709 0.431 1.741 0.878 0.687 1.743 Garchar CC 0.99 0.598 1.965 NA NA NA Garchar Fallow 1.17 0.833 1.968 NA NA NA Lewis CC 0.355 0.234 1.393 CC Failure CC Failure CC Failure Lewis Fallow 0.264 0.557 1.328 CC Failure CC Failure CC Failure Waschke CC 0.431 0.125 1.615 Safflower Safflower Safflower Waschke Fallow 0.583 0.274 1.384 Safflower Safflower Safflower SWCRC#1, CCM1 1.099 1.129 1.396 Wheat Wheat Wheat SWCRC#1, CCM2 0.847 0.98 1.31 Wheat Wheat Wheat SWCRC#1 Fallow 0.467 0.411 1.358 Wheat Wheat Wheat SWCRC#2, CT, CCM5

0.359 0.372 1.422 0.942 0.241 1.529

SWCRC#2, CT, CCM6 0.872 0.48 1.724 SWCRC#2, CT, Fallow 0.624 0.389 1.724 SWCRC#2, NT, CCM5

0.235 0.173 1.973 1.204 0.985 2.269

SWCRC#2, NT, CCM6 0.762 0.374 2.043 SWCRC#2, NT, Fallow 0.9 0.714 2.237

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2016 2017

Field/Treatment Infiltration rate

Steady-state

infiltration rate

Sorptivity Infiltration rate

Steady-state

infiltration rate

Sorptivity

CRP land* 0.62 0.489 1.525 *Lestina property

CONCLUSIONS AND DISCUSSION In 2015-2017, 19 summer/fall-planted cover crop mixes and six spring-planted cover crop mixes were tested. These mixes included legumes (e.g., pea, hairy vetch, clovers, sainfoin, and dry bean), grasses (rye, ryegrass, triticale, barley, oat, corn, sorghum sudan grass, pearl millet, and teff), brassicas (canola, rapeseed, radishes, forage collards, and turnip) and other broadleaves (flax, safflower, sunflower, buckwheat, and sunn hemp). The number of species in each mix varied from three to 10. The cover crop mixes were planted in fallow in the summer or early fall after wheat harvest or in the spring after the snow melts and the soil is dry enough for field operations. The only test where a cover crop, namely yellow sweet clover, was interseeded with winter wheat was not successful due the slow and low growth of yellow sweet clover before it was terminated in the spring when winter wheat was sprayed to control weeds. Seeding dates varied from July 29th to September 28th and from April 2nd to April 20th. Terminations dates were around June 10th in 2016 and June 20th in 2017. Seeding rates ranged from 10 to 43 lbs/acre and seed cost from $10/acre to $48/acre. The goal was to explore as many cover crop species and mixes as practical to determine their performance and their impacts on soil health and on the cash crop. We also wanted to test different management practices, so that we can narrow down the choice of species for the project area. This was important because of the lack of research-based information on cover crops in dryland cropping systems in the project area. It is too early to draw conclusions regarding the effects of cover crops on soil health or quality or on their agronomic or economic viability, but some trends have emerged.

1. Fall-planted cover crops produced considerably more biomass than spring-planted cover crops, which can be expected due to the longer growing season for the fall-planted cover crops. Dry matter of spring planted cover crops were generally less than 1000 lbs (average of 661 lbs/acre at SWCRC#2, 692 lbs/acre at Barry, and 242 lbs/acre at Crowley). Fall-planted cover crops at SWCRC#1 averaged 4512 lbs/acre in 2016 and 3438 lbs/acre at SWCRC#2 in 2017. The latter had a predominance of volunteer wheat. In two other fields that were monitored in 2017 but are not part of the project, fall-planted cover crops averaged 3007 lbs/acre in one field and 1857 lbs/acre in the other field on May 16, 2017. Winter triticale or winter rye were the dominant species in these fields. In one test, cover crops were planted on July 29, 2015, approximately one week after winter wheat was harvested. They produced 400 lbs/acre of dry matter in one field and 968 lbs/acre in another field before they were killed by a hard freeze in late October. The cover crop mix included warm season species such as sunflower, sorghum sudangrass, and Proso millet. More biomass was produced in the spring by the species (e.g., winter pea, purple top turnip, and yellow sweet clover) that survived the winter. The challenges of planting cover crops too early after wheat harvest are soil moisture

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availability and weed control, particularly volunteer wheat. Volunteer wheat was a main contributor to plant canopy and plant biomass in at least three trials. It may be considered a cover crop, except that it harbors diseases and insects (e.g., Russian wheat aphids, western bean cut worm) and will outcompete other cover crop species and limit plant diversity. The amount of volunteer wheat can be reduced by adjusting the combine settings (e.g. airflow) so that grain loss is minimal at harvest. Moreover, the time interval from wheat harvest until there is enough moisture to trigger seed germination varies from year to year and will determine how soon after wheat harvest one can control volunteer wheat and plant cover crops. That interval can be shortened with NT management since in the absence of tillage to prepare the seedbed, one can plant the cover crops earlier and spray the field (e.g., with glyphosate) to control volunteer wheat and other weeds before or shortly after planting the cover crops. No-till will also conserve moisture compared to CT. Volunteer wheat has not been much of an issue in spring-planted cover crops.

2. The more plant biomass is produced, the higher the uptake of soil moisture and nutrients, although some of the nitrogen for example can be temporarily immobilized by soil microbes. This was the case in six field tests whereby the amount of available N and moisture was markedly higher in the fallow treatment than in the cover crop treatment(s) prior to wheat planting. In three of these trials where winter wheat was planted in 2016 and harvested in 2017, wheat yield was substantially lower in the cover crop treatment than where no cover crops were planted. The difference was highly significant at SWCRC#1 which had three replications.

3. In the short-term, it appears that cover crops take up more nutrients than they contribute. This was certainly true for N. The question then is, “should there be restitution of the depleted nutrient e.g., by applying N fertilizer to the cash crop based on soil test recommendations?” This may not make up for the loss of soil moisture or may even exacerbate it by promoting vegetative growth at the expense of grain production. Water in the project area is undoubtedly the most limiting factor to crop production. The expectation is that in the long term, cover crops will enhance soil organic matter, which will increase soil water holding capacity. It would also improve soil structure, increase soil cover and soil biological activity, and thus improve water capture and reduce evaporation. Soil moisture storage and nutrient cycling will be enhanced, which would offset cover crop seed cost and management. Microbial biomass was generally higher in the cover crop than in the fallow treatment but the difference was either non-significant or its significance could not be established due to the lack of replications. Water infiltration rate was significantly higher (P=87%) in the cover crop than in the fallow treatment at SWCRC#1 in 2016 but there were no significant or apparent trends at the other test sites in 2016 or 2017. Soil sorptivity was significantly higher in NT than in CT at SWCRC#2 in 2017.

4. The notion that the more species in the cover crop mix, the better it is for soil health may be tough to achieve in the project area due to economic considerations and to limitations such as water scarcity and the relatively short growing season. Some species have not done well enough to warrant their inclusion in the cover crop mix in the future. These include teff, flax, sun hemp, crimson clover, berseem clover, and balansa clover. Hairy vetch shows promise

55

but its contribution to plant canopy and biomass was negligible at most test sites, compared to winter pea for example. Yellow sweet clover did well in two fields in the fall of 2015 and spring of 2016 but at other fields its stand was poor or nonexistent. Among the legumes, peas did the best. Nodulation was observed in some of the tests but not in others, which raises the question of how effective rhizobium inoculation was. When we ordered the seeds of leguminous crops, we made sure that they were inoculated with the specific rhizobium or we bought the inoculum separately and mixed it with the seeds. The viability and effectiveness of the rhizobium may have been affected by factors such the method of application and the conditions (e.g., temperature) during storage or shipping of the rhizobium or the treated seeds and soil condition (e.g., temperature, moisture, pH, etc.) at or following seed planting.

Winter rye performed well as did winter triticale. Spring barley and oat get established easily if there is adequate moisture but in our tests, they did not produce much biomass, which has more to do with the length of the growing season than with the species themselves. Sorghum sudangrass, corn, sunflower, pearl millet, and possibly other warm season plants will put up significant growth if planted early enough. This was the case in only one test where cover crops were planted in late July and the first freeze did not occur until late October, which was two to three weeks later than normal. Among the brassicas, Winfred turnip did the best. Rapeseed and canola either did not get established or were planted too late to survive the winter. Both do well in monoculture in SW Colorado. Small-seeded cover crops such as canola, rapeseed, and yellow sweet clover present challenges due to their seed size. They cannot be planted deep (e.g., more than half an inch) or their emergence may suffer. This can be exacerbated by soil crusting after a rain event. A poor stand will diminish the small-seeded cover crops ability to compete with weeds and with other cover crop species, and to overwinter. Ideally, the smaller seeds should be placed in a separate drill box (small seed box) than the larger seeds but so far in this project, all the cover crop seeds were mixed before planting them, which may affect seed flow and distribution.

Other considerations in selecting cover crop species and mixtures adapted to the project area include:

• Flowering and seed maturity--cover crops are usually terminated before any of the species makes viable seeds. In 2016, cover crops were terminated around June 10th but in 2017, they were terminated around June 20th, which was late since some of the species (e.g., oats and barley) made seeds.

• Winter or spring species—for many cover crop species, there are winter and spring varieties. Hence, it is important to order the variety that is adapated to the growing conditions where it will be planted. To help with the selection of cover crop species and varieties, one should consult the USAD Plant Hardiness Zone Map (http://planthardiness.ars.usda.gov/PHZMWeb/, verified on March 13, 2018).

5. Challenges encountered during this first phase of the project include:

a. Time constraints and other considerations which made it difficult to complete field operations (e.g., tillage and planting) on time in two of the on-farm trials.

http://planthardiness.ars.usda.gov/PHZMWeb/

56

b. Lack of replication in some of the on-farm trials or uniformity in management practices (e.g., cover crop mix, planting date, crop rotation). This makes it difficult, if not impossible, to do statistical analyses and draw valid conclusions. Fortunately, the two trials at the SWCRC are replicated, and three on-farm trials have more than one strip of the cover crop or fallow treatment.

These challenges are being addressed and will be ironed out before the start of the continuation project in 2018. Moreover, soil and plant sampling procedures and analyses will be reviewed and refined to address any deficiencies in terms of relevance or accuracy.

57

Appendix A: Additional Tables

58

Table 50. 2015 Monthly Precipitation in Yellow Jacket, Dove Creek, Eastland, and Monticello

Month

Yellow Jacket

CoAgMet Station

(in.)

Dove Creek

CoAgMet Station

(in.)

Eastland SCAN

Station (in.) Average

Dolores County

CoCoRahs (in)

Yellow Jacket

CoCoRahs* (in.)

GHCN Monticello

Station (in) Average

January 0.65 0.98 1.06 0.90 1.22 0.65 1.18 1.02 February 0.98 0.66 0.53 0.72 1.95 0.98 1.18 1.37 March 0.25 0.37 0.76 0.46 0.61 0.25 1.69 0.85 April 0.44 0.69 0.96 0.70 0.75 0.44 0.74 0.64 May 2.94 2.89 3.77 3.20 2.61 2.94 2.35 2.63 June 2.18 2.58 2.42 2.39 2.85 2.18 2.61 2.55 July 1.53 2.30 4.12 2.65 2.82 1.53 3.4 2.58 August 1.06 0.48 0.89 0.81 0.91 1.06 0.94 0.97 September 1.00 0.36 0.95 0.77 0.54 1.00 2.13 1.22 October 1.44 3.22 3.17 2.61 3.11 1.44 3.94 2.83 November 1.36 1.36 1.50 1.41 2.87 2.00 1.77 2.21 December 0.44 0.44 0.02 0.30 3.11 2.53 1.61 2.42 Total 14.27 16.33 20.15 16.92 23.35 17.00 23.54 21.30

* SWCRC did not start reporting CoCoRahs data until November 3, 2015. All previous precipitation data was taken from SWCRC CoAgMet. * Dove Creek CoAgMet Station failed to report from 11//2015 through 12/31/2015. SWCRC CoAgMet Data was substituted in that timeframe.

59

Table 51. Long-term precipitation averages in Yellow Jacket, Dove Creek, Eastland, and Monticello

Month

NOAA 1981-2014

Yellow Jacket Average Monthly

Precipitation (in.)

NOAA 1981-2014 Dove Creek Average

Monthly Precipitation

(in.)

2007-2017 Eastland SCAN

Average Monthly

Precipitation (in.)

NOAA 1981-2014 Monticello

Average Monthly

Precipitation (in.)

January 1.53 1.33 0.70 1.59 February 1.30 1.20 0.40 1.41 March 1.35 1.18 0.40 1.18 April 1.46 1.14 0.50 0.96 May 1.03 0.92 1.30 0.84 June 0.50 0.53 0.50 0.61 July 1.56 1.18 1.50 1.29 August 1.70 1.47 1.70 2.02 September 2.05 1.70 1.90 1.83 October 1.84 1.76 1.20 1.65 November 1.42 1.15 1.00 1.36 December 1.27 1.34 0.80 1.49 Total Annual Precipitation 17.01 14.90 11.90 16.23

60


Month

SWCRC CoAgMet

Station Monthly Precip.

(in.)

Dove Creek

CoAgMet Station

Monthly Precip.*

(in.)

Eastland SCAN

Station Precip.

(in.) Average

Dolores County

CoCoRahs Monthly Precip.

(in)

SWCRC CoCoRahs Monthly Precip.

(in.)

GHCN Monticello Station (in) Average

January 0.60 0.60 0.71 0.64 1.92 2.47 1.42 1.94 February 0.02 0.02 0.04 0.03 1.04 1.11 1.14 1.10 March 0.25 0.31 0.10 0.22 0.65 0.38 0.50 0.51 April 0.63 0.52 0.02 0.39 0.92 0.61 1.40 0.98 May 1.32 1.22 1.58 1.37 1.02 1.48 1.47 1.32 June 0.06 0.21 0.49 0.25 0.11 0.06 0.32 0.16 July 2.56 1.33 1.15 1.68 1.65 2.6 1.66 1.97 August 1.65 1.64 2.28 1.86 2.06 1.87 4.30 2.74 September 1.04 0.69 0.85 0.86 1.0 1.14 1.63 1.26 October 0.06 0.14 0.15 0.12 0.22 0.07 0.39 0.23 November 1.14 0.23 0.73 0.70 1.5 1.65 1.35 1.50 December 1.56 1.36 1.07 1.33 2.50 2.32 1.67 2.16 Total 10.89 8.27 9.17 9.44 14.59 15.76 17.25 15.87 * Dove Creek CoAgMet Station failed to report from 1/1/2016 to 3/22/2016. SWCRC CoAgMet Data was substituted in that time frame

61


Month

SWCRC CoAgMet Station

Monthly Precip

(in.)

Dove Creek

CoAgMet Station

Monthly Precip

(in.)

Eastland SCAN

Station Precip

(in.) Average

Dolores County

CoCoRahs Monthly

Precip (in)

SWCRC CoCoRahs Monthly

Precip (in.)

GHCN Monticello

Station (in) Average

January 1.45 1.22 1.16 1.28 3.96 3.55 2.85 3.45 February 0.84 0.67 0.77 0.76 1.16 1.49 1.05 1.23 March 0.70 0.66 0.71 0.69 0.84 0.93 0.70 0.82 April 0.45 0.29 0.06 0.27 0.79 0.65 0.51 0.65 May 1.08 0.65 0.46 0.73 1.06 1.25 1.19 1.17 June 0.00 0.04 0.02 0.02 0.00 0.02 0.17 0.06 July 2.30 1.77 2.08 2.05 1.84 2.56 1.90 2.20 August 0.57 0.16 0.33 0.35 0.54 0.68 1.13 0.61 September 1.76 0.00 0.75 0.84 1.11 1.95 1.27 1.44 October 0.04 0.00 0.00 0.01 0.00 0.08 0.14 0.07 November 0.10 0.05 0.05 0.07 0.01 0.02 0.12 0.05 December 0.01 0.00 0.00 0.00 0.24 0.09 0.34 0.22 Total 9.30 5.51 6.39 7.07 11.55 13.26 8.34 11.05

62

Table 54. Monthly Temperature at the CoAgmet Station in Yellow Jacket, CO

Yellow Jacket CoAgMet Average Monthly Temp Yellow Jacket CoAgMet

Average Maximum Temp Yellow Jacket CoAgMet

Average Min Temp

2015 2016 2017 NOAA Normals

1981-2010 2015 2016 2017 2015 2016 2017 January 32.5 23.8 27.1 38.5 42.7 33.6 34.8 22.3 14.0 19.4 February 37.3 38.4 36.0 41.7 48.1 50.0 44.1 26.5 28.3 28.0 March 43.7 41.0 43.9 49.3 55.6 53.1 55.8 31.8 29.0 32.0 April 46.4 45.1 45.0 59.0 59.6 57.5 57.3 33.2 32.6 32.8 May 51.2 52.1 53.2 69.1 62.6 65.4 66.6 39.9 38.7 39.8 June 66.1 69.5 68.5 79.5 79.0 85.4 84.1 53.3 53.6 53.0 July 67.1 71.1 69.8 84.8 79.5 85.4 84.4 54.8 56.8 57.9 August 69.4 65.8 67.3 82.1 83.1 78.6 81.0 55.8 53.1 55.0 September 63.3 60.3 60.3 74.4 78.4 72.5 73.5 48.2 48.1 48.6 October 53.3 53.7 50.6 61.8 64.3 65.9 64.0 42.3 41.5 37.8 November 35.4 42.3 44.8 49.2 45.7 52.9 57.4 25.0 31.7 33.7 December 26.4 29.2 35.1 39.6 35.9 38.5 47.2 16.9 19.9 24.7

63

Table 55. Monthly Temperature at the CoAgmet Station in Dove Creek, CO

Dove Creek CoAgMet Average Monthly Temp Dove Creek CoAgMet Average

Maximum Temp Dove Creek CoAgMet Average

Min Temp


1981-2010 2015 2016 2017 2015 2016 2017 January 32.0 NA 27.1 28.3 43.6 NA* 35.2 20.4 NA 19.1 February 35.0 NA 36.7 31.6 49.4 NA 46.6 20.6 NA 26.7 March 42.3 NA 43.3 38.5 57.0 NA 58.9 27.7 NA 27.7 April 45.1 44.3 44.5 45.3 60.5 58.8 59.8 29.7 29.8 29.2 May 51.0 51.7 52.8 55.4 64.3 66.7 69.4 37.7 36.6 36.1 June 65.4 67.9 67.6 65.5 82.2 87.4 87.7 48.7 48.4 47.6 July 67.7 71.0 71.4 71.7 82.7 88.2 89.0 52.6 53.7 55.4 August 69.1 66.5 68.0 69.5 85.4 81.4 85.3 52.9 51.6 51.1 September 63.6 60.5 66.3 62.0 80.8 76.4 83.6 46.3 44.6 49.2 October 52.9 52.2 48.8 49.9 65.6 68.5 65.8 40.1 36.0 31.9 November NA 41.3 42.6 38.1 NA 55.2 58.9 NA 27.4 27.1 December NA 27.8 33.0 28.4 NA 39.9 49.5 NA 15.8 18.9 *NA: Not available

64

Table 56. Monthly Temperature at the SCAN Station in Eastland, UT

Eastland SCAN Average Monthly Temp Eastland SCAN CoAgMet Average Maximum Temp

Eastland SCAN CoAgMet Average Min Temp

2015 2016 2017

2007-2017 Average

Temperature 2015 2016 2017 2015 2016 2017 January 30 23 26 25 57 50 48 3 1 -1 February 35 31 35 30 59 58 53 14 -3 14 March 42 40 44 39 68 63 69 12 20 12 April 45 44 46 45 71 71 70 20 25 20 May 50 53 54 54 78 74 79 30 30 26 June 67 71 71 67 93 94 93 42 42 40 July 66 72 71 71 92 92 85 47 50 59 August 68 66 69 68 88 90 82 51 47 56 September 64 60 61 61 83 82 74 43 37 49 October 51 53 49 49 80 72 63 30 29 36 November 34 40 44 37 59 65 64 11 12 16 December 25 28 33 25 51 47 55 3 5 11

65

Table 57. Monthly Temperatures at GHCN station in Monticello, UT

GHCN Monticello Average Monthly Temp GHCN Monticello Average

Maximum Temp GHCN Monticello Average Min

Temp


1981-2010 2015 2016 2017 2015 2016 2017 January 30 25 26 25 39 34 34 21 16 19 February 36 32 34 29 47 43 44 25 22 25 March 42 40 43 37 54 53 55 30 27 30 April 44 44 44 45 57 56 56 31 31 32 May 50 50 52.3 54 61 63 65 37 37 39 June 64 69 62.4 63 79 84 76 50 53 49 July 66 70 70.7 69 79 84 85 53 56 57 August 68 64 66.2 67 81 77 80 55 51 52 September 63 58 60.7 59 77 72 75 49 44 47 October 52 52 47.9 47 63 65 62 41 39 34 November 35 40 42.8 35 46 52 56 24 29 30 December 25 27 33.6 26 35 37 47 16 18 21

66

Table 11. SWCRC #1 Trial Information (Soil type: Wetherill Loam, Sharps-Cahona)

Treatments Season/

Year Date/

Operation Fallow CCM#1 CCM#2 CCM#3

Fall 2015 9/28/2015 Plant Fall

Cover Crop Not Applicable

Hairy Vetch (14%), YSC (3%), Winter

Pea (83%) 28.9 lbs/acre, $34.16/acre


Pea (48%), Winter Rye (43%)

35.2 lb/acre, $31.92/acre


Pea (34%), Winter Rye (53%), Winfred Turnip (3%), Winter

Canola (3%) 28.3 lbs/acre, $29.63/acre

Spring 2016

6/10/2016 Cover Crop

Termination Not Applicable Terminated Cover Crop - Tractor Mounted Rotary Mower

6/17/2016 Cover Crop

Termination & Weed

Management

Weed Management in Fallow and Cover Crop Termination - Spray Glyphosate @ 2 pt/acre ($7.68/acre), 2,4-D @ 0.5 pt/acre ($1.36/acre)

Fall 2016

8/3/2016 Weed

Management Sprayed Glyphosate @ 1 qt./acre ($7.04/acre)

9/18/2016 Weed

Management Sprayed Glyphosate @ 1.25 qt./acre ($8.80/acre)

9/19/2016 Plant Cash

Crop Fairview Hard Red Winter Wheat @ 50 lbs/acre

Summer 2017

6/20/2017 Harvest Cash

Crop

61.4 bu/acre, 15.0% crude protein


45.5 bu/acre, 13.9% crude protien


8/23/2017 Weed/

Volunteer Wheat Control

Sprayed Glyphosate @ 40 oz/acre ($8.00/acre)

8/30/2017 Plant Fall


Mix 1 - Winter Pea (83%), Hairy Vetch

(14%), Yellow Sweet Clover (3%), 28.9

lbs/acre, $22.56/acre

Mix 2 - Winter Pea (48%), Winter Rye (43%), Hairy Vetch (8%), Yellow Sweet Clover (2%), 35.2

lbs/acre, $22.48/acre

Mix 3 - Winter Pea (34%), Winter Rye (53%), Hairy Vetch

(6%), Winfret Hybird Turnip (3%), Winter Canola (3%), Yellow Sweet Clover (1%),

28.3 lbs/acre, $19.62

67

Table 15. SWCRC #2 Trial Information – Conventional Tillage (Soil Type: Wetherill Loam, Sharps-Cahona)

Treatments Season/

Year Date/

Operation CCM 1-5 CCM 6-8 Fallow

Summer 2016


Crop (Baseline

Yield/Quality)

Winter Wheat Harvest, Average Yield: 43 bu/ac, Average Protein: 19.8%

8/8/2016 Disc Ground Tandem Disc, 3 passes


Cover Crop Plant CCM 1-5 Not Applicable (NA) NA

9/19/2016 Weed &


NA Disc

Spring 2017

3/20/2017 & 4/7/2017 Weed &


Re-growth of CCM1-5 that overwintered

Chisel plow - 3/20/2017, Filed cultivate - 4/7/2017

4/13/2017 Plant Spring Cover Crop

NA Plant CCM 6-8 NA

6/20/2017 & 6/23/2017 Terminate

Cover Crops

CCM1-5 plots mowed with

brush hog NA NA

All CCMs terminated with tandem disc NA

8/4/2017 Weed

Control Cultivate with sweeps

Summer 2017

9/20/2017 Seedbed Prep & Weed/

volunteer wheat control

NA Cultivate with sweeps

68

Treatments Season/

Year Date/

Operation CCM 1-5 CCM 6-8 Fallow

Fall 2017

9/21/2017 Seedbed Prep & residue

management

Disc NA NA


Crop Plant HRWW (Fairview) 55 lbs/acre

Summer 2018

Harvest Cash Crop

Data to be Collected: Yield, Protein, % Moisture, Test Weight, Falling Number

69

Table 16. SWCRC #2 Trial Information – No Till (Wetherill Loam, Sharps-Cahona)

Treatments Season/

Year Date/ Operation CCM 1-5 CCM 6-8 Fallow

Summer 2016


Crop (Baseline Yield & Quality)

Winter Wheat Harvest, Average Yield: 43 bu/ac, Average Protein: 19.8%

8/11/2016 Plant Fall Cover

Crop Plant CCM 1-5 NA NA

Fall 2016 10/17/2016


The Aug'16-planted CCMs continue to grown, no spraying

conducted. Sprayed glyphosate at 40 oz/acre

Spring 2017

4/12/2017 Weed &

Volunteer Weed Control

The Aug'16-planted CCMs continue to grown, no spraying

conducted. Sprayed glyphosate at 40 oz/acre


Spring re-growth of CCM1-5 species that overwintered Plant CCM 6-8 NA

Summer 2017

6/20/2017 & 6/21/2017

Termiante Cover Crops

The Aug'16-planted CCMs mowed with a brush hog. NA

All CCM plots sprayed with 32 oz/acre Glyphosate, 8 oz 2,4-D Amine

Fall 2017 9/21/2017 Plant Cash Crop Plant HRWW (Fairview) 55 lbs/acre

Summer 2018

TBD Harvest Cash Crop


70

Table 22. Barry Middle Trial Information (Soil type: Cahona Series)

Treatments Season/

Year Date/

Operation Winter Wheat w/ Yellow Sweet

Clover - Approx. 61 acres Winter Wheat Only - Approx. 8

acres

Summer 2015

8/2/2015 Weed Control 2,4-D LV6 at 0.5 pint/acre


Crop Winter Wheat Harvest, 28 bu/acre average yield

9/2/2015 Volunteer

Wheat Control Buccaneer Plus at 1.5 quarts/acre

9/6/2015 Plant Cash Crop Juniper Hard Red Winter Wheat at 30 lbs/acre

9/6/2015 Interseed

Yellow Sweet Clover

Yellow Sweet Clover broadcast seeded @ 4lbs/acre, $7.80/acre Not Appicable

Spring 2016

4/2/2016 Terminate

Yellow Sweet Clover

Dicamba at 4 oz/acre & 2,4-D LV6 at 1/3 pint/acre Not Appicable

Summer 2016


Crop

Winter Wheat Harvest - Estimated Yield: 27.7 bu/acre, Protein:

11.8%

Winter Wheat Harvest - Estimated Yield: 33.8 bu/acre,

Protein: 11.9% 8/22/2016 Volunteer

Wheat & Weed Control (Spray)

Buccaneer Plus at 1 qt./acre, 2,4-D LV6 at 1/3 pint/acre, Banvel 4 oz/acre

Fall 2016 10/10/2016 Apply Soil

Ammendment Applied MB906 Bacteria, 1 gallon/acre, $8.75/gallon

New Trial/Treatments Two fallow strips (16 acres) Three CCM strips (58 acres)

Spring 2017


Mixture (CCM)

Not Applicable

Spring Oats (16%), Spring Pea (62%), Rapeseed (1%), Hairy

Vetch (14%), Flax (2%), Safflower (4%). 24.25 lbs/acre, $14.30/acre

6/19/2017 Terminate CCM Not Applicable

Terminated Spring Cover Crop - Herbicide - Glyphosate 1 qt./acre

+ 2,4-D LV6 1/2 pt/acre + Dicamba 4 oz/acre

Summer 2017

8/29/2017 Plant Cash Crop Plant Winter Wheat (Juniper HRWW 35 lbs/acre)

71

Treatments Season/

Year Date/

Operation Winter Wheat w/ Yellow Sweet

Clover - Approx. 61 acres Winter Wheat Only - Approx. 8

acres

Summer 2018

TBD Harvest Cash

Crop


72

Table 27. Barry WSW Trial Information (Soil type: Cahona Series)

Treatments

Season/ Year Date/Operation

Winter Wheat w/ Yellow Sweet Clover - Approx. 47

acres

Winter Wheat Only - Approx. 6 acres

Summer 2015

7/24/2015 Harvest Cash Crop Harvested Winter Wheat, 22.5 bu/acre average yield

9/1/2015 Volunteer Wheat

Control

Buccaneer Plus @ 1.5 qt/acre ($11.52/acre) & 2,4-D LV6 @ 1/3 pt/acre ($0.90/acre)


9/5/2016 Interseed Yellow

Sweet Clover

Yellow Sweet Clover broadcast seeded @ 4lbs/acre, $7.80/acre

Not Applicable

Spring 2016

4/2/2016 Terminate Yellow

Sweet Clover

Dicamba @ 4 oz/acre, 2,4-D LV6 @ 1/3 pt./acre

($0.90/acre) Not Applicable

Summer 2016

8/15/2016 Harvest Cash Crop

Winter Wheat Harvest Estimated Yield: 16.0

bu/acre, Protein: 9.8%

Winter Wheat Harvest Estimated Yield: 16.5 bu/acre, Protein:

10.5%

Fall 2016 10/10/2016 Apply Soil Amendment Applied MB906 Bacteria, 1 gallon/acre, $8.75/gallon

New Trial/Treatments Two fallow strips (9 acres) Three CCM strips (46 acres)

Spring 2017

4/13/2017 Plant Spring Cover

Crop Not Applicable

Spring Barley (36%), Spring Pea (24%), Crimson Clover (21%),

Nitro Radish (19%). 22.4 lbs/acre, $10.06/acre

Summer 2017

6/19/2017 Terminate Spring


Glyphosate 1 qt./acre ($6.40/acre) + 2,4-D LV6 1/2

pt/acre($1.12/acre), Dicamba 4 oz/acre

8/29/2017 Plant Cash Crop Plant Winter Wheat (Juniper HRWW 35 lbs/acre)

Summer 2018 Harvest Cash Crop Data to be Collected: Yield, Protein, % Moisture, Test Weight,

Falling Number

73

Table 32. Barry ESW Trial Information (Soil type: Cahona Series)

Treatments

Season/ Year Date/ Operation

Fallow - Approx. 8 acres Cover Crops (CCM) - Approx. 45 acres

Summer 2015


Crop Winter Wheat Harvest, 22.5 bu/acre average yield

7/29/2015 Plant Fall Cover Crop Not Applicable

Winter Peas-25%, Nitro Radish-5%, Purple Top Turnip-5%, Sunflower-5%,

Teff-5%, Berseem Clover-10%, Sorghum-Sudan-10%, Proso Millet-10%, Buckwheat-20%, Yellow Sweet Clover -

5% @ 15.5 lbs /acre, $19.95/acre

Spring 2016

3/11/2016 Terminate Fall


Buccaneer Plus @ 1.5 qt/acre ($10.56/acre), 2,4-D @ 0.5 pt/acre

($1.12/acre)

4/2/2016 Plant Spring Cover

Crop Not Applicable

Spring Pea - 26%, Forage Barley 32%, Spring Oats 32%, Rapeseed 3%,

Safflower 3%, Flax 5% @ 38 lb/acre, $12.05/acre

Summer 2016

6/11/2016 Terminate Spring


Buccaneer Plus @ 1.5 qt/acre ($10.56/acre), 2,4-D LV6 @ 0.5 pt/acre

($1.12/acre)

8/29/2016 Weed Control

Buccaneer Plus @ 1 qt/acre ($7.04/acre), 2,4-D LV6 @ 0.5 pt/acre ($1.12/acre), Banvel @ 4 oz/acre ($2.04./acre)



Amendment Applied MB906 Bacteria, 1 gallon/acre ($8.75/gallon)

Summer 2017


Crop

32.5 bu/acre, 14.1% crude

protein 25.2 bu/acre, 15.0% crude protein

9/12/2017 Weed Control Sprayed 2,4-D LV6 at 1/3 pint/acre ($0.75/acre)

9/16/2017 Plant Cover Crop Not Applicable

Winter Peas (68%), Hairy Vetch (12%), Nitro Radish (10%), Winter Triticale (10%), 20.5 lbs/acre, $14.63/acre

74

Table 36. Barry North Trail Information (Soil type: Monticello Series)

Treatments

Season/Year Date/ Operation

Fallow - Approx. 7 acres Cover Crop - Approx. 40 acres

Summer 2015


Crop Winter Wheat Harvest, 10 bu/acre average yield

7/31/2015 Plant Fall Cover

Crop Not Applicable

Winter Peas-25%, Nitro Radish-5%, Purple Top Turnip-5%, Sunflower-5%, Teff-5%, Berseem Clover-10%, Sorghum-Sudan-10%, Proso Millet-10%, Buckwheat-20%, Yellow Sweet

Clover - 5% @ 15.5 lbs /acre, $19.95/acre

Spring 2016



Buccaneer Plus @ 1.5 qt/acre ($10.56/acre), 2,4-D LV6 @ .5

pt/acre ($1.36/acre)


Not Applicable

Spring Pea - 26%, Oat -32%, Barley-32%, Rapeseed-3%, Safflower-3%,

Flax-5%, @ 15.5 lb/acre , $12.05/acre

6/11/2016 Terminate

Spring Cover Crop

Not Applicable Buccaneer Plus @ 1.5 qt/acre ($10.56/acre), 2,4-D LV6 @ .5

pt/acre ($1.36/acre)

Summer 2016

8/22/2016 Weed Control

(Spray)

1qt/ac buccaneer plus ($7.04/acre), ½ pt/acre of 24D LV6 ($1.36/acre), 4oz/acre Banvel ($2.04/acre)

9/3/2016 Plant Cash

Crop Juniper Hard Red Winter Wheat at 30 lbs/acre


Amendment Applied MB906 Bacteria, 1 gallon/acre, $8.75/gallon

Summer 2017


Crop

32.5 bu/acre, 11.6% crude protein 24.2 bu/acre, 12.2% crude protein

9/12/2017 Weed Control Sprayed 2,4-D LV6 at 1/3 pint/acre ($0.75/acre)

9/17/2017 Plant Cover

Crop Not Applicable

Winter Peas (52%), Sunflower (24%), Hairy Vetch (14%), Sorghum

Sudangrass (10%), 21 lbs/acre, $14.90/acre

75

Table 39. Crowley-Nebeker Trial Information (Soil type: Monticello series)

Treatments

Season/ Year Date/ Operation Fallow - Approx. 9 acres Cover Crop - Approx. 20 acres

Summer 2015


Crop Winter Wheat Harvest: 34.3 bu/acre average yield

8/27/2015 Seedbed

Preparation Disc - 1 pass



Winter Lentils- 22%, Winter Peas- 44%, Rapeseed- 5%, Nirtro Radish

7%, Forage Collards 4%, Flax- 18% - 25 lbs/acre - $30/acre

Spring 2016


Cover Crop Field Cultivate with points and harrow - 1 pass

5/12/2016 Weed Control Field Cultivate with sweeps and harrow - 1 pass


Crop Organic Safflower at 15 lbs/acre

Fall 2016 11/15/2016

Harvest Cash Crop

Estimated Yield: 898 lbs/acre, Oil: 35.1%, Test Weight: 39.5

lbs/bu, Moisture: 6.4%

Estimated Yield: 763 lbs/acre, Oil: 35.5%, Test Weight: 38.5 lbs/bu,

Moisture: 6.0%

Spring 2017

4/14/2017 Plant Cover

Crop Not Applicable

Spring Pea (44%), Crimson Clover (14%), Sunn Hemp (14%), Proso Millet (11%), Nitro Radish (6%),

Impact Forage Collards (6%), Sunflower (6%). $16.16/acre, 18.2

lbs/acre 6/20/2017 Terminate Cover Crop

Not Applicable Field Cultivate with sweeps - 1 pass

Summer 2017

7/6/2017 Weed Control Field Cultivate with sweeps - 1 pass

9/7/2017 Weed Control Field Cultivate with sweeps - 1 pass

Fall 2017 10/6/2017 Plant Cash

Crop Hard Red Winter Wheat (curlew) 60 lbs/acre

Summer 2018

Harvest Cash Crop


76

Table 43. Garchar Trial Information (Soil type: Granath Series)

Treatments

Season/ Year Date/ Operation Fallow - Approx. 20 acres

Cover Crop - Approx. 20 acres

Spring 2016

4/6/2016 Weed Control (Spray) Round-up 1 qt/acre

4/22/2016 Plant Spring Cover Crop Not Applicable

Fixation Balansa (43%), Ryegrass (20%), Frosty

Berseem Clover (16.6%), Crimson Clover (13.3%), Radish (6.6%) $43.38/ac,

15 lbs/ac

Summer 2016

7/6/2016 Terminate Spring Cover Crop

(Implement) Not Applicable Disc - 1 Pass


Sorghum-Sudan (22%), Barley (14%), Dry Beans (29%), Oats (7%), Corn (3%), Maple Peas (7%), Sunflower (3%), Yellow

Peas (14%) $14.68/acre, 34.5 lbs/ac

Fall 2016 10/21/2016 Terminate Fall Cover Crop Not Applicable Winterkill

Spring 2017

5/15/2017 Herbicide Application Glyphosate 2 qt/acre

5/29/2017 Tillage field cultivate - 1 pass

Summer 2017


Winter Peas (64%), Winter Triticale (15%),

Corn (10%), Hairy Vetch (10%), 39 lbs/acre,

$26.39/acre

77

Table 46. Lewis Trial Information (Soil type: Monticello Series)

Treatments Season/

Year Date/ Operation Fallow - Approx. 17 acres Cover Crop - Approx. 29 acres

Summer 2014

8/30/2014 Plant Cover Crop Not Applicable

Buckwheat (18%), Winter Pea (12%), YSC (12%), Oats (12%),

W. Triticale (12%), Sudangrass (12%), Purple Top

Turnip (6%), Tillage Radish (12%), 17.5 lbs/acre,

$16.66/acre

Spring 2015

4/15/2015 Terminate Cover

Crop Not Applicable Buccaneer Plus @ 1 qt/acre,

2,4-D LV6 at 0.5 pt/acre

6/15/2015 Weed

Management Buccaneer Plus @ 1 qt/acre, 2,4-D LV6 @ 0.5 pt./acre

Summer 2015

7/15/2015 Weed


8/15/2015 Weed


8/30/2015 Fertilizer

Application Urea (45-0-0) @ 80 lb/acre

9/10/2015 Plant Cash Crop Hard Red Winter Wheat

Summer 2016


Crop

Winter Wheat Harvest: Estimated Yield: 40.4

bu/acre, 16.6% Protein, entire field average 37

bu/acre

Winter Wheat Harvest: Estimated Yield 60.8 bu/acre,

15.1% Protein, entire field average 37 bu/acre

Fall 2016

11/15/2016 Tillage

Operation Tandem disc - 2 passes

12/6/2016 Dormant Seed


Cowpeas (15%), Sainfoin (34%), Yellow Sweet Clover (15%), Pearl Millet (10%), Tillage Radish (5%), Flax (20%), Purple Top Turnip

(1%). 20.3 lbs/acre, $48.39/acre

78

Treatments Season/

Year Date/ Operation Fallow - Approx. 17 acres Cover Crop - Approx. 29 acres

Spring 2017 5/16/2017

Terminate Cover Crop

Weed Management Moldboard Plow & Cultivator

Terminated via Moldboard Plow & Cultivator

Summer 2017

8/15/2017 Weed

Management Tordon at 1/2 pint/acre, 2,4-D LV6 at 1/2 pint/acre

Fall 2017

9/25/2017 Soil Amendment

Pig Manure at 1 ton/acre ($50/ton + $20/ton shipping) Not Applicable

9/26/2017 Plant Cash Crop Plant Hard Red Winter Wheat (juniper) 45 lbs/acre

Summer 2018

Harvest Cash Crop


79

Table 49. Waschke Trial Information (Soil type: Cahona Series)

Treatments Season/

Year Date/ Operation Fallow - Approx. 33 acres

Cover Crop - Approx. 33 acres

Fall 2014 10/29/2014 Plant Cover Crop Not Applicable

Organic Austrian Winter Peas, 20 lbs/acre,

$28.82/acre

Summer 2015

6/20/2015 Terminate Cover

Crop Not Applicable Disc - 1 pass

9/15/2016 Pre-Plant Tillage Field cultivate with sweeps - 1 pass

Fall 2015 10/3/2016 Plant Cash Crop Juniper Hard Red Winter Wheat at 60 lbs/acre

Summer 2016

8/2/2016 Harvest Cash Crop





8/15/2016 Post Harvest

Management Chisel with sweeps - 1 pass

Fall 2016 11/7/2016 Post

Harvest Management

Ripper - 1 pass

Spring 2017 5/2/2017 Plant Cash Crop Organic Safflower (CW990L) at 13.3 lbs/acre

Fall 2017 Harvest Cash Crop 509 lbs/acre 509 lbs/acre

Spring 2018 Plant Cover Crop Not Applicable Cover Crop Mix TBD

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Appendix B. Additional Figures

81

Figure 3. SWCRC #1 Plot layout

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Figure 4. SWCRC #2 Plot Layout

83

Figure 5. Barry Middle Field Layout

84

Figure 6. Barry West half, SW Field Layout

85

Figure 7. Barry East half, SW Field Layout

86

Figure 8. Barry North Field Layout

87

Figure 9. Crowley-Nebeker Field Layout

88

Figure 10. Garchar Field Layout

89

Figure 11. Lewis Farms Field Layout

90

Figure 12. Waschke Field Layout

Technical Bulletin TB-1 Ag ricultural · Colorado State University, Southwestern Colorado Research...

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