Submitted to: Agricultural and Environment Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/18/1996
Publication Date: N/A
Technical Abstract: Detection of herbicides and nitrate-nitrogen in surface and ground water in Iowa and the Midwest has prompted concern about linkages between agricultural practices and environmental quality. The Management Systems Evaluation Area (MSEA) program was developed to accomplish two goals: 1) to evaluate the distribution of agrichemicals in water resources and identify the processes and factors that affect their concentration and distribution, and 2) to develop alternate and innovative agricultural management systems that enhance and protect environmental quality. The Iowa project of the MSEA program has focused on four research objectives at four sites to identify the effects of different management practices across a range of soils, climate, and hydrogeological units. These sites are intensively studied to determine the transport and rate of degradation of atrazine, alachlor, metribuzin, and metolachlor and cycling of nitrogen in continuous corn and corn-soybean rotations under tillage, herbicide, and nitrogen management practices. Concentrations and loads of atrazine and metolachlor were largest in the streamflow with runoff events shortly after application in the spring. In-stream nitrate-nitrogen concentrations decreased during surface runoff events. Movement of herbicides and nitrate-nitrogen through the soil profile into the ground water is dependent upon numerous factors including the soil water balance, herbicide characteristics, and the soil nitrogen budget. Understanding how the components of farming systems affect the transport and fate of agricultural chemicals permits the development and modification of farming practices that will enhance and protect environmental quality.