Start Date: Apr 17, 2012
End Date: Apr 16, 2017
This project will conduct research to investigate the effects of agricultural management practices at field and watershed scales, the dynamics of watershed hydrology, and fundamental processes relevant to contaminant behavior in watersheds. Under the first objective, field studies will evaluate practices that can reduce loss of nitrate-nitrogen from cropped fields. These practices include resaturated buffers and bioreactors, practices that intercept tile drainage, and two practices that can reduce N loss to tiles, namely side-dressing of anhydrous ammonia and fall-planted cover crops. Bioreactor denitrification capacities will be assessed with microbiological assessments, and modeling studies will be conducted to extend experimental results on conservation practices to other areas of the Midwest. Research will be conducted to develop and evaluate watershed analyses to place conservation practices for improved water quality outcomes and determine how those strategies can be regionalized across the Midwest. Conservation needs also exist in urban environments and an experiment to determine how compost amendments can reduce urban runoff will be carried out. The second objective will be conducted in three Iowa watersheds, where stream monitoring will provide databases for watershed modeling studies, and for testing hypotheses about impacts of changes in climate and land use on water quality and hydrology. This research will be supported by efforts to identify field-scale patterns of hydrology and water quality, and better understand how new mapping techniques using Light Detection and Ranging (LiDAR) data can assist in understanding field hydrology, river corridor management, and targeting of conservation practices. The third objective will employ a mix of laboratory and field studies to evaluate environmental transport and residence times of pathogens and veterinary pharmaceuticals in soils and streams, and determine if exposure to trace antibiotic residues in soil or stream sediment affect the persistence of antibiotic resistant bacteria and antibiotic resistance genes. A breadth of watershed monitoring, controlled experiments in field and laboratory, and modeling techniques will be employed in the research. Publications, tools for conservation planning, and databases available to other scientists will be produced. Results are intended to enable agriculture to better manage water resources for multiple needs, particularly in the Upper Mississippi River basin.