- Agronomic: corn, rye
- Crop Production: cover crops
- Pest Management: cultural control
Despite numerous environmental benefits associated with cover crops including reducing erosion, improving infiltration, mitigating nutrient loading in surface waters, and improving soil health (Kaspar et al 2001, Kaspar and Singer 2011, Schnepf and Cox 2006), many farmers are reluctant to include cover crops in their production systems because of reported yield declines, especially in corn. There are numerous potential reasons for this yield decline, including seedling disease that reduces stand, and seedling vigor that leads to uneven stands. Cover crops, especially grass cover crops, are hosts of the same pathogens that infect corn seedlings (Bakker et al 2016). Cover crops serve as a 'green bridge' for pathogens by maintaining pathogen populations over the winter between harvest and planting of cash crops, which is normally when pathogen numbers decline on non cover crop fields (Smiley et al 1992; Acharya et al 2017). The objective of this project is to understand the effects of two winter rye cover crop seeding methods on corn disease, growth and development. To accomplish this we will work closely with a farmer collaborating with the Iowa Soybean Association On-Farm Network for two years. The field will be no-till corn-soybean rotations with three replications of the winter rye cover crop seeded on 30- inch rows or drilled in 7-inch rows. The corn will be planted on 30-inch rows causing two spacings between corn and decomposing rye. To compare the two methods, stand count, seedling vigor and root rot will be assessed at growth stage V2-V3, and final stand count, number of harvestable ears and stalk rot will be assessed at growth stage R6. The results of our project will improve understanding of rye cover crop methods and corn disease on corn growth and development, and consequently yield, and enable us to develop best management practices for farmers. Current cover crop farmers will be informed on how to decrease corn seedling diseases and non cover crop farmers will be encouraged to include rye cover crops on their fields. Our outreach and output efforts will be evaluated by means of social media, number of citations and surveys. This project will improve the profitability of farmers by reducing the risk of yield reductions in corn while improving the soil and water quality, and providing a best management practice for farmers.
Project objectives from proposal:
We expect the results of our project to increase the understanding of the effect of two winter rye cover crop seeding methods on corn disease, corn growth and development. Yield reductions in corn sometimes occur when the crop is planted after a rye cover crop (Miguez and Bollero 2005; Carlson 2012; Kaspar and Bakker 2015). My research will develop best management practices (BMPs) for farmers to reduce the risk of yield reductions in their corn crops following a rye cover crop. Consequently, this will inform current cover crop farmers how to decrease the risk corn seedling disease and consequently reduced yields associated with a decomposing rye cover crop. In addition, developing improved BMPs for introducing cover crops into corn soybean rotations will encourage non cover crop farmers to include a rye cover crop on their fields. More acres planted to cover crops will reduce nutrient loss and soil erosion, and consequently result in better water quality.