Impact of Liquid Swine Manure Application and Cover Crops on Ground Water Quality

The primary objective of this project was to determine the impact of appropriate rates of swine manure applications to corn and soybeans based on nitrogen and phosphorus requirements of crops, soil phosphorus accumulation, and the potential of nitrate and phosphorus leaching to groundwater. Another purpose of this long-term experimental study was to develop and recommend appropriate manure and nutrient management practices to producers to minimize the water contamination potential and enhance the use of swine manure as inorganic fertilizer. A third component of this study was to determine the potential effects of rye as a cover crop to reduce nitrate loss to shallow ground water

Using Lysimeters and Tile Drained Field Plots to Study the Leaching of Field Applied Poultry Manure and UAN into Tile Water

Six lysimeters and eleven tile drained field plots were used to determine if the amount of contaminants leaching into tile water would increase after the application of poultry manure and urea ammonium nitrate fertilizer (UAN). There were three nitrogen based treatments applied to the lysimeters and fields: 168 kg N/ha of UAN, 168 kg N/ha of poultry manure, and 336 kg N/ha of poultry manure. (One treatment per lysimeter/field plot.) Corn was planted in the lysimeters and field plots, as well as soybeans in the field plots, in order to simulate field conditions. Tile water samples were collected once a week and after rain events and tested for nitrate, total phosphate, orthophosphate, E. coli, and total coliform. Results thus far indicate that larger amounts of manure/fertilizer applied to lysimeters/field plots appear to predispose the lysimeters and field plot soils to greater contaminate leaching potential. E. coli, total coliform, and total phosphate leaching increased when heavy rain events occurred, while nitrate and orthophosphate leaching decreased