Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: July 5, 2000
Publication Date: N/A
Technical Abstract: Leaching of nitrates from agricultural land poses health risks when drinking water aquifers are contaminated and nitrate levels exceed the 10 ppm US EPA standard. By combining computer simulation models with GIS technology, areas of greatest concern can be identified and delineated. Current BMPs in these sensitive areas can be evaluated using models that predict their impacts on nitrate losses to groundwater. New recommendation concerning crop selection and BMPs can then be explored. This study compares various combinations of perennial and annual crops, soil types, climates, management practices, and economic scenarios using the computer model GLEAMS (Groundwater Loading Effects from Agricultural Management Systems) for the purpose of developing improved BMPs for agricultural land overlying sensitive aquifers. Research suggests that perennial plant species use water and nitrogen over a longer period and in larger amounts than annual crops, and that a switch from annual crops to perennial forage results in significant decreases in leaching losses. By using computer simulation models and GIS to first identify areas of concern, then explore the impacts of switching management systems to appropriate mixes of perennial and annual crops in these areas, sensitive aquifers may be protected from further nitrate contamination.