Suppression of Soybean Diseases Through the Use of Cover Crops

Project Overview

Project Type: Research and Education
Funds awarded in 2010: $174,823.00
Projected End Date: 12/31/2013
Region: North Central
State: Illinois
Project Coordinator:
Dr. Darin Eastburn
University of Illinois

Annual Reports


  • Agronomic: canola, rapeseed, rye, soybeans


  • Crop Production: cover crops
  • Education and Training: extension, on-farm/ranch research, participatory research, workshop
  • Pest Management: biological control, cultural control, integrated pest management, mulching - vegetative
  • Soil Management: green manures, organic matter, soil microbiology

    Proposal abstract:

    Soybean diseases cause significant annual reductions in soybean yield. Yet soybean production relies on only three limited disease management strategies, crop rotation, resistant varieties, and fungicides. Some cover crops are known to produce allelopathic and glucosinolate compounds which impact soilborne pathogen levels and soil microbial populations, resulting in increased levels of disease suppression.

    In this project, growers, researchers, and extension personnel will collaborate in university and on-farm trials in western, central, and southern Illinois to evaluate the efficacy and feasibility of using cover crops for disease suppression in soybeans. As a result, growers and the academic community will increase their knowledge on the use of four cover crops for suppressing soybean diseases, and they will better understand how cover crops can integrate with current production practices.

    Growers and researchers will share their results at field days and newly organized alternative disease management workshops. Results will be reported on websites, in popular-press and scientific publications, and at research and extension meetings. Participating growers will serve as resources to help educate other growers on the usefulness of using cover crops.

    Progress will be monitored by evaluating levels of disease suppression by cover crops and through farmer input on the feasibility of their use. Surveys will be used at outreach events during and after the research project to assess the continued impact on grower practices. Additional and sustainable disease management strategies are needed to increase yield stability and improve the environmental impacts of soybean production. Implementation of the recommendations of this project will help us achieve that goal.

    Project objectives from proposal:

    This research will benefit organic and conventional soybean growers interested in soil building, sustainable agricultural practices, as well as extension educators and crop consultants (CCA’s) who desire information on alternative disease management methods. The outcomes from this project will be useful to soybean growers in the North Central Region.

    The primary goal of the project is to evaluate the potential for using cover crops to reduce levels of soilborne and foliar diseases of soybean. Understanding the impact that cover crop residues have on pathogenic organisms and disease processes will enhance our knowledge and aid in the development of sustainable disease management strategies for soilborne and foliar soybean diseases.

    Outcomes from this project will include an increase in knowledge of cover crop use for alternative disease control, providing growers another tool to combat soybean diseases, as well as an increased understanding of how cover crops impact soil microbial populations, how different cover crops work to control disease, why cover crops are needed, and how to use them effectively in rotation with soybean.

    Short term outcomes will include an increased knowledge and skill of farmers, extension, CCA’s, and researchers about using rye and Brassica cover crops in a traditional soybean/corn rotation. The findings will provide a better understanding of the compatibility of cover crops with both organic, and conventional soybean production systems, as well as an increase in the knowledge of soil microbial activities in response to cover crop systems, and an understanding of the effectiveness and benefits of using cover crops for disease management in soybeans. On-farm trials will provide farmers and researchers with firsthand observation of the usefulness of cover crops for suppressing soybean diseases and an understanding of how cover crops integrate with current production practices.

    The intermediate term outcomes will include increasing the number of producers that include cover crops as part of their rotation plan for soybean production, as well as the knowledge base of those producers for using cover crops effectively. In addition a graduate student will be trained in the area of alternative disease management, and extension educators will become more familiar with the use of cover crops in soybean production systems. This project will provide a venue through which producer/participants can mentor other producers about their use of cover crops and the potential for disease suppression. This will reduce the amount of soybean yield lost annually to important soybean diseases. It also will provide farmers with an alternate disease management strategy that can complement other strategies, such as using disease resistant cultivars, or reducing the need for seed treatment and/or foliar fungicides.

    Long-term outcomes will include improved disease suppressiveness of crop production soils and an increase in soybean yield and yield stability. A reduction in the use of seed treatment and foliar fungicides will help prevent the development of pathogen resistance. The education and outreach efforts will foster an increase in the adoption of integrated pest management (IPM) practices by farmers in the north central region. Associated benefits of increasing the use of cover crops will include improved soil quality, nutrient and moisture retention, wildlife cover, and weed management, as well as reductions of soil erosion.


    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.