Identification of effective cover crop varieties and integrated management practices for weedy and invasive plant suppression in the Western US

Project Overview

Project Type: Graduate Student
Funds awarded in 2020: $25,000.00
Projected End Date: 07/31/2022
Host Institution Award ID: G157-21-W7902
Grant Recipient: Utah State University
Region: Western
State: Utah
Graduate Student:
Principal Investigator:
Dr. Corey Ransom
Utah State University


  • Agronomic: clovers, corn, peas (field, cowpeas), soybeans, vetches, wheat
  • Additional Plants: native plants


  • Crop Production: application rate management, catch crops, cover crops, crop rotation, cropping systems, double cropping, drought tolerance, intercropping, irrigation, no-till, varieties and cultivars
  • Education and Training: decision support system, demonstration, display, extension, mentoring, on-farm/ranch research
  • Farm Business Management: agricultural finance, budgets/cost and returns
  • Natural Resources/Environment: biodiversity
  • Pest Management: competition, cultural control, integrated pest management, mulches - living, weed ecology
  • Production Systems: dryland farming, organic agriculture
  • Soil Management: green manures
  • Sustainable Communities: community services, employment opportunities, local and regional food systems, new business opportunities, public participation

    Proposal abstract:

    Weedy and invasive plant species are one of the major causes of yield losses in agricultural systems (Flessner et al. 2019, Soltani et al. 2016, Soltani et al. 2017, Soltani et al. 2018, WERA-77). The arid Western US is lacking in cover crop research and the development of best management practices for weed suppression utilizing cover crops and integrated strategies. Producers have identified this need for understanding the competitive ability of cover crops against weeds, including most effective seeding rates and timing, and their incorporation into an integrate approach for Western US cropping systems (Cann et al. 2019). In this proposed two-year study, we will identify the types of cover crops and best-integrated strategies for the use of these practices in the Western US. Types of cover crops will be tested within different cropping systems using a range of management approaches. Integrated weed management tactics of seeding dates, rates, and cover crop types will be tested in an irrigated wheat system for suppressing weeds, specifically Kochia scoparia. We will measure cover crops competition with weeds and cash crops and also examine their potential future weed threat. The outcome of these studies will be the identification of cover crops best suited for practical use alone and in integrated weed management in the Western US. Results will be disseminated through fact sheets, educational meetings, development of a regional cover crop selection tool, and partial budgets accounting for these practices. Surveys and interviews will be conducted to discern the likelihood of practice adoption.

    Project objectives from proposal:

    The objectives are to: 1) test cover crops types in terms of weed suppression, cash crop interference, and potential weediness in multiple crops, mainly corn and wheat and 2) develop an optimal IWM approach for wheat that incorporates various cover crop planting dates, seeding rates, and types.

    For both objectives the following methods will be used:

    The determination of the cover crops with the greatest efficacy in weed suppression in arid regions of the Western US will be accomplished using cover and biomass data. Measuring the density and composition of weed species once a month across the growing period each year through percent cover measurements will identify the competitive ability of the cover crop against the weeds. Through harvesting shoot growth from the plots at the time of cash crop harvest and over a month later will reveal long-term effects of the competitive cover crop-weed interaction.

    These metrics will also be applied to the cash crop to show if there is an influence on cash crop development. Additionally, cash crop yield data will be calculated each year from the samples taken, which will allow for the identification of the cover crop influence on crop yield.

    To identify potential of future weed issues caused by the cover crop, seed rain of the cover crops will be collected each year and tested for germination in the lab and surveyed in the field during the following growing season for each year of the study.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.