The Impact of Poultry Manure on Water Quality Using Tile Drained Field Plots and Lysimeters

Abstract

A six-year study was conducted to determine the effects of four experimental treatments [168 kg N/ha from poultry manure (PM), 168 kg N/ha from urea-ammonium nitrate (UAN), 336 kg N/ha from poultry manure (PM2), and 0 kg N/ha (control treatment)] on corn and soybean yields, grain quality, corn stalk N, soil NO3-N, soil PO4-P, subsurface tile drain water quality, runoff water quality, and bacteria concentrations in subsurface drain and runoff waters. Eleven field plots were planted to a corn-soybean rotation, while six lysimeters were planted to continuous corn. Conclusions indicate that the PM treatment is the better choice in applying nutrients to fields because of high yields, which were significantly higher than the UAN treatment and similar to the higher rate PM2 treatment. In addition, the PM treatment resulted in reduced levels of soil NO3-N levels compared to UAN treatment and lower soil PO4-P trends compared to the PM2 treatment. Also, the PM treatment resulted in reduced NO3-N losses in subsurface drain water as compared to the UAN and PM2 treatments. Bacteria concentrations in subsurface drain and runoff waters from the PM2 treatment were higher in comparison with the UAN and PM treatments. Additionally, the bacteria concentrations from the PM2 treatment were double the concentrations of the PM treatment. Thus, as long as the poultry manure is applied at reasonable nitrogen rates (of 168 kg N/ha), it makes a good soil amendment, gives better crop yields, and reduced NO3-N concentrations in subsurface drain water compared to 168 kg N/ha from UAN and 336 kg N/ha from poultry manure.