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

View the project final report

• 2016 annual report

Commodities

Practices

• Crop Production: cover crops, crop rotation, fallow, nutrient cycling
• Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research, participatory research, workshop
• Farm Business Management: budgets/cost and returns, feasibility study
• Soil Management: green manures, organic matter, soil analysis, soil microbiology, soil quality/health
• Sustainable Communities: public participation

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. The main goal of this project is to determine how cover crops can enhance the sustainability of dryland farming on the Colorado Plateau. The research will be conducted in southwestern (SW) Colorado and southeastern (SE) Utah where dryland crop production is practiced at relatively high elevations (≥ 6,000 ft), soils have low organic matter (≤ 1%), and where annual precipitation averages 10 to 16 inches, with June being the driest month of the year. Cover crops have been shown to increase soil biological diversity, reduce soil erosion, enhance soil fertility, and suppress weeds, and may also provide quality forage as a value-added component to conventional production systems. These benefits are attainable in humid and irrigated environments, but there is little information for dryland cropping systems as is our semi-arid, high elevation environment on the Colorado Plateau. We face additional challenges due to relatively low moisture, frequent high winds, and soils that crust easily, which makes it difficult to extrapolate research results from other farming areas. Most crop rotations in the project area feature winter wheat as the lead crop and may include dry bean, safflower or sunflower. The fallow period between crops may last less than a month after a bean crop to 14 months between two wheat crops. Clean fallow whereby several tillage operations, including moldboard plowing, are performed to control weeds and prepare the seedbed is the norm, although some innovative farmers have begun practicing no-till and mulch till. This kind of farming exposes the soil to wind and water erosion, accelerates organic matter loss, and uses a great deal of energy for the many tillage operations required to keep the fallow free of weeds. In this project we will grow cover crop mixtures during the fallow period on five participating farmers’ fields. We will monitor changes in soil moisture, soil erosion, soil fertility, soil biological activity, weed population, and crop yield on ground that was planted to cover crops versus ground not cover cropped. We will track the costs and returns associated with planting cover crops and determine which cover cropping strategies produce a net income. Cover crop species and mixtures will be tailored to each farm and cropping system. The same mixtures will be tested at Colorado State University’s Southwestern Colorado Research Center in a replicated trial. The information gained will be shared with a wide audience via annual field tours and workshops, a video production documenting the project’s progress and main findings, social media, five publications, and presentations at relevant events. Success will be measured by how well the project objectives are met, by the interest generated by this project, and by the number of producers who have planted or plan to include cover crops in their farming operation.

1. 1. Test cover crops on five farms and at the Research Center. Three of the farms will be in San Juan County, UT and two in Dolores County, CO. The on-farm tests will include traditional crop rotations (wheat-fallow, wheat-bean, and wheat-safflower-fallow) and management practices (conventional tillage) and less traditional cropping systems such as wheat-wheat-fallow, no-till management, or organic crop production. Cover crops will include single species such as Austrian peas, yellow sweet clover, and black medic, and mixes of up to nine species. Some will be interseeded (black medic or yellow sweet clover) with winter wheat; others will be planted in the summer following wheat harvest or in early spring. The trial at the Research Center in Yellow Jacket, CO will replicate the main cropping systems tested on farmers’ fields at a smaller scale. Stability analysis will be performed to compare treatments with and without cover crops for all the trials. Testing a wide range of cover crops, crop rotations, and management practices will give us a good picture of what works or does not work and will pave the way for further studies after this project is complete.

1. 1. Evaluate the performance of cover crops and determine their effects on soil moisture, soil fertility, weed control, soil biology, soil erosion, and on the succeeding cash crop. Baseline data will be collected at the start of each trial and yearly measurements will be made to assess the agronomic feasibility of cover crops in dryland cropping systems in the project area.

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

1. 1. Educate farmers and others about cover crops and disseminate project results. This will be achieved via:
      • • Yearly field tours and workshops
      • • A project documentary video
      • • Factsheets, CSU/AES Technical Bulletins, and two refereed journal articles
      • • Presentations at growers meetings, workshops, and other relevant events in Colorado and Utah.

1. 1. Gauge the project’s impact by how well the outreach events are attended, feedback from each event, and the number of acres planted to cover crops since this project started. NRCS will continue to track the number of additional applications for cover crop grant assistance and will assist with long term monitoring of cover crop practice adoption.