Cereal Cover Crops for Weed Control in Organic and Conventional Dry Bean Production Systems

View the project final report

Commodities

• Agronomic: barley, triticale, wheat
• Vegetables: beans

Practices

• Crop Production: cover crops, cropping systems, no-till
• Education and Training: on-farm/ranch research
• Pest Management: allelopathy, chemical control, integrated pest management, weed ecology
• Production Systems: organic agriculture
• Soil Management: soil quality/health

There has been substantial interest in cover crops in our region, especially from farmers who grow specialty and small-acreage crops like dry bean. This has been driven primarily by goals of weed suppression, erosion control, and protecting crops from wind damage. Despite the profound interest, the adoption of cover crops in Idaho remains one of the lowest in the United States. Demonstrating the short-term weed suppression and potential economic benefits may increase the adoption and integration of cover crops into cropping systems. Cereal cover crops can be effective at suppressing weeds, however, maximizing suppressive ability is dependent on management practices that promote biomass production at the time of cash crop planting.  Cover crops (wheat, barley, and triticale) were planted in the fall of 2022. Cereal cover crops were either terminated with herbicide (glyphosate) or harvested for forage. In an organic system cover crops will be tilled. In the conventional system, there were five herbicide treatments; three preemergence, one postemergence herbicide treatment, and one nontreated check where there was no herbicide spraying. Data were collected on soil moisture, soil temperature, soil health, dry bean stand density, weed control, crop yield, as well as economic analysis. It is expected that cover crops will increase labile carbon, suppress weeds, and not negatively impact bean yield. Results will be disseminated to stakeholders through field days, bean school presentations, extension publications, and peer-reviewed publications. Results from this project will provide the foundational knowledge needed by stakeholders to adopt and integrate cover crops to maximize weed suppressive benefit, reduce reliance on herbicides, and minimize the potential for negative yield impacts.

Research Objectives:

• Quantify biomass production and weed suppression of fall-planted cover crops
  • Evaluate how termination practice (chemical termination vs haying) affects weed suppression ability of fall-planted cereal cover crops in dry bean.
• Evaluate weed suppression and dry bean response to cereal cover crops in an organic production system.
• Evaluate changes in soil labile carbon in cereal cover crop – dry bean production systems.
• Use crop yield and input cost to quantify the economic impact of integrating cereal cover crops and herbicides for weed control in dry bean.

Educational objective(s):

• Educate producers and stakeholders on cover crops and management practices that optimize weed suppression and soil health benefits, and profitability