Effects of Poultry Manure Application on the Leaching of NO3-N to Subsurface Drainage Water

Abstract

<p>Excessive use of poultry manure on croplands is likely to impact the quality of groundwater resources. A three year study was conducted on eight, 0.4 ha plots, and six, 2.1 m2 lysimeters, to determine the effect of poultry manure and nitrogen fertilizer applications on NO3-N leaching to shallow groundwater. Three application rates of N (168 kg-N/ha from urea ammonium nitrate fertilizer, 168 kg-N/ha and 336 kg-N/ha from poultry manure) were applied to field lysimeters and plots before planting corn (Zea mays L). Corn-soybean rotation was practiced in field plots while only corn was grown in lysimeters. No fertilizer or manure was applied to subplots where soybeans were grown. Subsurface drainage water samples were collected weekly and analyzed for nitrate-nitrogen (NO3-N) during the study period (1998 – 2000). The results of the study indicate that poultry manure application rate of 168 kg-N/ha resulted in the lowest NO3-N concentration and loss with subsurface drainage water in comparison with similar application of commercial N fertilizer. Higher NO3-N concentrations and losses with drainage water were observed from lysimeters in comparison with field plots. Data on NO3-N concentrations in subsurface drain water clearly shows the effects of preferential flow immediately following heavy rainfall events.</p>