Development of winter cover crop varieties and complementary mixtures for North Central Region grain systems

View the project final report

• 2007 annual report
• 2008 annual report

Commodities

• Agronomic: corn

Practices

• Crop Production: cover crops, intercropping, multiple cropping, nutrient cycling
• Production Systems: agroecosystems
• Soil Management: green manures, nutrient mineralization, organic matter

Winter cover crops have the potential to supply a host of economic and environmental services for grain farmers in the North Central Region (NCR). Alternative nutrients obtained from winter legumes combat rising fertilizer prices while vegetative cover sustains soil health. Red clover and hairy vetch are the only legume cover crops that survive NCR winter conditions, but are also difficult to manage and often become weeds in succeeding cash crops. Phenological and morphological knowledge of hairy vetch and red clover varieties and mixtures must be distributed to farmers in order for them to successfully manage their cover crops. On many NCR farms, extreme winter climactic conditions limit hairy vetch and red clover vigor, especially in dry-land systems. Farmers can buffer winter plant stresses through enhanced genetic diversity within a cover crop species. Certain complementary mixtures within winter-hardy legume species have the potential to maximize resource use throughout the season. An experiment will be conducted at the Kellogg Biological Station (KBS) for three years to assess varieties of hairy vetch and red clover for beneficial characteristics and to make specific genotypic combinations that buffer changing winter conditions. Two farms, one in Michigan and one in Nebraska, will be used as research sites during the second and third years for the most promising varieties and combinations observed at KBS. Farmers will aid in making decisions about which mixtures fit their farms and will have the opportunity to participate in future on-farm selection processes. Understanding of the botany of red clover and hairy vetch under controlled research conditions and in real farm situations will allow us to effectively manage these winter cover crops, which are essential for NCR grain farmers using low input methods.

Intermediate-term outcomes will include more efficient resource use by winter cover crop communities in the North Central Region (NCR) inducing tighter nitrogen cycling. Enhanced diversification of plant genotypes and species will aid in buffering against harsh climactic and environmental conditions. Nitrate leaching and external inputs will be reduced while soil and particulate organic matter will be increased, thus enhancing the sustainability of cropping systems.

Short-term outcomes will include enhanced farmer knowledge of winter-hardy hairy vetch (Vicia villosa) and red clover (Trifolium repens) varieties and importance of intraspecific diversity for Nebraska and Michigan dry-land corn-soybean-wheat rotational systems. Farmers will have options for legume establishment and vigor following corn and soybean harvests that extend into early to mid October and will be able to effectively manage the cover crop in the spring. Environmental and economic costs and benefits of growing genetically diverse legume covers with other winter cover crop species such as cereal rye (Secale cereale) and winter rape (Brassica napus) in dry-land rotations will be identified.