Center Pivot Application of Processed Swine Effluent to Crops.

Animal waste management is a significant environmental issue in Illinois. This project is designed to compare the use of separated liquid swine effluent collected from a solid-liquid separator and compost made from separated solids from liquid swine manure as soil amendment for corn and soybean production. Manure solids are separated from effluent with the aid of a polymer material and gravity screens. The separated solids are composted with other materials, such as urban landscape waste. The remaining effluent is stored in holding tanks and subsequently irrigated on the experiment site. The field site (University Farm at Lexington, IL) has uniform soil (Chenoa-Drummer-Graymont Association), with 1 to 2% slope, good drainage, soil pH of 6, organic matter content of 4 to 5%, and good fertility. A corn/soybean rotation has been employed, with soybean (Glycine max) grown at the site in 2007 and 2009 and corn (Zea mays) in 2006, 2008, and 2010. Typical agronomic practices of Central Illinois grain producers were utilized in this study. To facilitate the use of center pivot irrigation each plot contains 16.2 hectares of land. Two annual treatments were evaluated; processed liquid swine effluent and compost made from separated solids of liquid swine manure. A preliminary analysis of the data indicates that the two treatments responded in a similar fashion for measured plant parameters like seed and stover yields. In contrast, the annual application of solid-separated compost increased soil P and Zn levels, compared to separated effluent. These results need to be verified over a number of years to assess seasonal variability patterns.