2008 Annual Report
1a.Objectives (from AD-416)
Evaluate management systems for growing corn with perennial groundcover
1b.Approach (from AD-416)
A field study using three perennial groundcover species with different competitive abilities and four groundcover management treatments and a no groundcover control will be conducted for three growing seasons. Groundcover treatments will involve chemical and mechanical control for suppression during active corn growth. In-season assessments of plant water status, carbon dioxide exchange, nutrient sufficiency, radiation interception, and dry matter production will isolate temporal patterns of plant-plant competition between corn and the groundcover. Groundcover species will be drilled into a conventionally-tilled seedbed in late summer. Corn will be planted in the same groundcover plots for three years following establishment. A randomized complete block design in a split-plot arrangement of treatments with four replicates will be established. Groundcover main plots will be 19.0 m wide and 22.8 m long and include white clover, Kentucky bluegrass (Poa pratensis L.), creeping red fescue, and a mixture of white clover and red fescue. Management system subplots will be 3.8 m wide and 22.8 m long and include.
1)a control without a groundcover,.
2)groundcover using a pre- and post corn emergence 25-cm glyphosate herbicide band,.
3)groundcover with a spring broadcast paraquat (non-selective non-translocated herbicide) burndown and post glyphosate band,.
4)groundcover with 25-cm fall strip-tillage and glyphosate band, and.
5)groundcover with fall strip tillage, spring paraquat burndown, and post glyphosate band.
Research being conducted under this agreement directly supports Objective 3 "Evaluate cover crop and living mulch genotypes and species for corn-soybean agroecosystems in the Midwest that maintain main crop yields, increase soil organic matter, and reduce nitrate leaching" of the parent project. During the reporting period, all perennial groundcover plots were planted and managed to prepare for corn planting, instruments to monitor soil water were installed, and treatments within groundcover species whole-plots were initiated. Continuous soil water data are being collected daily and other measurements are occurring as planned at the research site. Saturated soil from above-average rainfall has delayed corn growth and development at this writing. Monitoring of agreement progress and success during the past year has occurred through careful attention to site management and regular reviews of agreement expectations and commitments by ARS personnel associated with this project.