Date of Award
Master of Science
Agricultural and Biosystems Engineering
Agriculture and Biosystems Engineering
Michelle L. Soupir
Nitrogen (N) and Phosphorus (P) are primary nutrients required for plant growth, but agricultural nitrogen and phosphorous losses through tile drainage systems pollute downstream waters. The objectives of this study were to assess the effects of poultry manure (PM) application to continuous-corn cropping system on nitrogen and phosphorous losses and crop yields from 2010 to 2014. Soil test sampling at 0 – 15 cm and 15 – 30 cm depth were collected each spring, prior to fertilizer application which included poultry manure at 112 kg﹒ha-1 (PM), poultry manure at 224 kg﹒ha-1 (PM2), and urea ammonia nitrogen at 224 kg﹒ha-1 (UAN). Water samples were collected from drainage tiles weekly and following precipitation during the research period (2010-2014) with tile drainage flow recorded by Neptune T-10 meters. PM (7879 kg﹒ha-1) and PM2 (8756 kg﹒ha-1) application rates resulted in significantly greater yields, without considering the impacts of phosphorous and other micro nutrients. PM2 applications rate resulted in greater corn yield while at the same time contributing similar NO3-N load (43.4 kg﹒ha-1) and concentration (38.7 mg﹒L-1) to tile waters in comparison with UAN (51.9 kg﹒ha-1, 43.5 mg﹒L-1). The PM application resulted in lower NO3-N load (13.8 kg﹒ha-1) and concentration (13.5 mg﹒L-1) and larger crop yield than UAN. UAN treatment had lower PO4-P load (0.017 kg﹒ha-1) and concentrations (0.004 mg﹒L-1) when compared to the PM (0.027 kg﹒ha-1, 0.01 mg﹒L-1) and PM2 (0.029 kg﹒ha-1, 0.019 mg﹒L-1) treatments. PM was found to be the best treatment for both acceptable crop yields and the lowest nutrient losses with the NO3-N concentration closest to the 10 mg·L-1 NO3-N MCL of drink water set by the U.S. EPA.
Wu, Chenkai, "Long term effect of poultry manure application on water quality, yield under a corn-corn system in Iowa" (2016). Graduate Theses and Dissertations. 15179.