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Corn management following cereal rye cover crop with strip tillage and starter N fertilization (2018-2020)
Issue: Cover crops are a conservation practice that can have tremendous benefits for improving soil health and reducing nutrient losses. There is limited research available on management practices that provide farmers information to facilitate cover crop adoption and minimize potential yield limiting factors.
Objective: Evaluate the effects of a winter rye cover crop-free zone through the use of strip-tillage and starter fertilizer to improve seedling vigor and eliminate yield drag associated with winter cereal rye. This objective will be reached by elucidating treatment effects on: 1) corn growth and development throughout the growing season; 2) disease, insect and weed incidence, severity, and prevalence; and 3) winter cereal rye biomass growth and nutrient uptake.
Approach: This study will be conducted at the ISU Agricultural Engineering and Agronomy Farm (AEA) and one outlying research farm. Experimental treatments will consist of two tillage systems (strip-tillage and no-tillage) and three starter N fertilizer rates. Cover crops will be seeded in the fall into soybean. Cover crops will be terminated 10-14 days ahead of corn planting for all treatments as per current recommendations. Cover crop and corn crop growth and development parameters will be collected throughout the respective life cycles. Corn seedling roots will be evaluated for root rots. Insect incidence and weed density/community notes will be determined.
Improving cereal rye cover crop BMPs to increase adoption of cover crops by Iowa farmers (2018-2020)
Issue: The Iowa Nutrient Reduction Strategy (INRS) calls for cover crop implementation on over 12 million acres, which equates to every other field. Despite numerous environmental benefits associated with cover crops, many farmers are still hesitant to change their current production practices. Major barriers to introducing cover crops as a conservation practice include cost of implementation, yield drag, and knowledge. This multi-disciplinary team will address the barriers of using cover crops and develop best management practices (BMPs) for including a cover crop in a corn-soybean production system in Iowa for “hesitant” farmers. Using these data, we will develop a set of BMPs with a partial cost budget to encourage farmers to include cover crops in corn-soybean production systems, and therefore meet the INRS goals of cover crop acreage adoption in Iowa.
Objective: This research will evaluate the effect of cover crop seeding rate, seeding method, and termination timing on corn production, soil health and nutrient recycling. Treatment effects on (i) cover crop and corn growth and development (ii) weed, pest and disease pressure, (iii) nutrient recycling and (iv) soil health will be assessed. In addition, partial budgets for treatments will be developed, and Iowa farmers surveyed to identify common methods of seeding cover crops users and perceived efficacy of those methods.
Approach: A comprehensive field study at the ISU Ag Engineering and Agronomy Farm, with smaller studies at the ISU Southeast Research Farm, Crawfordville, and Northwest Research Farm, Sutherland will be done. Experimental treatments will consist of a three seeding rates, two planting methods (drilled and broadcast) seeding rates, and rye termination timing. Cover crops will be seeded after soybean. The following data will be collected: cover crop growth and development in the fall and spring; corn growth and development throughout the growing season; weed, insect and disease pressure; soil and plant nitrate, soil health parameters. Relationships between data variables will be evaluated to improve our understanding of factors influencing the winter rye-corn cropping systems.