Examining Cover Crops for Soil Health Restoration in Dryland Cropping Systems in SW Colorado and SE Utah

View the project final report

Commodities

• Agronomic: wheat

Practices

• Crop Production: cover crops, cropping systems
• Education and Training: on-farm/ranch research, participatory research
• Production Systems: agroecosystems
• Soil Management: soil quality/health

Cover crops have gained considerable attention in recent years as an important option for improving soil health and productivity on farms around the US. However, dryland agricultural systems in the western part of the country present a unique set of opportunities and challenges for cover crops. The Colorado Plateau, in particular, has a relatively short growing season along with low and erratic precipitation. Wheat-based cropping systems in the region rely on tillage and herbicide applications to keep soils bare for much of the year, and this has resulted in widespread soil degradation due to low organic matter inputs and erosion. Cover crops can help to counteract such losses in soil fertility and long-term productivity, but may also compete for water with cash crops and their net benefit remains largely unstudied in the Colorado Plateau.

Given the lack of research on cover crops in the high desert region, this project seeks to fill a critical information gap for local dryland producers. The proposed work will build on research conducted in the first phase of this project and assess the on-farm performance of different cover crop mixtures as well as the medium-term impact of cover crops on crop yields, overall farm profits, soil health, and a range of ecosystem services (e.g. soil water capture, erosion control, carbon sequestration, forage provision, weed control). Additionally, we will incorporate new research elements that emerged from Phase I (Western SARE Project SW15-008), including the testing of soil inoculants and alternative termination strategies of cover crops to minimize tillage. This project and the evolving directions of this research have grown directly out of local producer and stakeholder discussions, and represent a truly collaborative effort to understand the potential of cover crops to enhance long-term profitability and environmental quality of the region.

1. Evaluate the growth and performance of different cover crop mixtures within different environmental and rotational contexts in multiple producers’ fields and at the Southwest Colorado Research Center (SWCRC) (Fonte, Russell, Schipanski, Berrada, Eash, Lockard, participating farmers). Mixtures will be comprised of functionally similar species combinations (considering legumes vs. grasses, fibrous vs. tap roots, warm vs. cool season, etc.) across fields/farms and rely largely on locally available seed.
2. Assess medium-term (4-6 yr) impacts of cover crops on soil health and soil-based ecosystem services. Ecosystem services of interest include water capture and storage, crop production, erosion control, and potential forage provision. Additional soil health parameters include the maintenance of soil structure, soil C dynamics, and soil microbial diversity and activity (Fonte, Trivedi, Schipanski, Parslow, Eash, Lockard).
3. Conduct economic analysis of cover crops to understand the net balance of establishment costs, differences in weed management and labor expenditures, and subsequent impacts on crop yields (Beiermann, participating farmers).
4. Examine alternative management techniques to address emerging grower concerns (Russell, Trivedi, Fonte, Eash, Lockard). Specifically, these will include testing effectiveness of different legume inoculation techniques within cover crop mixtures as well as alternative termination methods (e.g. crimping - for application in organic systems) to foster the development of reduced tillage practices.
5. Engagement with producers, community members, and other stakeholders to share project results and discuss the benefits and challenges associated with cover crops (Russell, Fonte, Eash, Lockard, and all participants). This will be achieved via:
   1. Annual workshops and field days with local stakeholders in Montezuma and Dolores Counties, CO, and San Juan County, UT.
   2. CSU/AES technical bulletins, factsheets, and peer-reviewed journal articles.
   3. Presentations of project results at regional conferences, workshops, and extension events in other parts of Colorado, Utah and the broader Western SARE region.
   4. Project videos (interviews, presentations, etc.).
   5. Regular updates and posting of materials (e.g. videos, presentations, technical bulletins) on project website (http://drylandcovercrops.agsci.colostate.edu/).
   6. Outreach to local schools to engage next generation farmers and agricultural researchers.
6. Evaluate the project’s impact and reach (Westerman, Boswell). This will be achieved by documenting how well the outreach events are attended and obtaining feedback from each event.