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, 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, Lestina, Schipanski, Roseberry,
Berrada, 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, potential forage provision, and weed control. Additional soil health
parameters include the maintenance of soil structure, soil C dynamics, and soil microbial
diversity and activity (Fonte, Trivedi, Schipanski, Parslow, Roseberry).
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, Roseberry, participating farmers).
4. Understand the potential of perennial species mixtures to contribute towards longer-term soil
restoration on low productivity and/or degraded soils. This objective also seeks to establish a
reference against which annual cover crop mixtures can be compared in terms of their
potential to support soil health and ecosystem services (Fonte, Russell, Roseberry, McCart).
5. Examine alternative management techniques to address emerging grower concerns (Russell,
Roseberry, Lestina, Trivedi, Fonte). 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.
6. Engagement with producers, community members, and other stakeholders to share project
results and discuss the benefits and challenges associated with cover crops (Russell, Fonte,
and all participants). This will be achieved via:
• Annual workshops and field days with local stakeholders in Montezuma and Dolores
Counties, CO, and San Juan County, UT.
• CSU/AES technical bulletins, factsheets, and peer-reviewed journal articles.
• Presentations of project results at regional conferences, workshops, and extension events
in other parts of Colorado, Utah and the broader Western SARE region.
• Project videos (interviews, presentations, etc.).
• Regular updates and posting of materials (e.g. videos, presentations, technical bulletins)
on project website (http://drylandcovercrops.agsci.colostate.edu/).
• Outreach to local schools to engage next generation farmers and agricultural researchers.
4
7. Evaluate the project’s impact and reach (Westerman, Lestina, Roseberry, Boswell, Nay). This
will be achieved by documenting how well the outreach events are attended and obtaining
feedback from each event. Additionally, we will track the number of acres planted to cover
crops in the region since the start of the project. NRCS will continue to provide information
on the number of additional applications for cover crop grant assistance, and will assist with
long term monitoring of cover crop practice adoption.