Date of this Version
Thesis (M.S.)—University of Nebraska—Lincoln, 1973. Department of Agronomy.
Feedlot waste control requirements in many locations have necessitated collection of the runoff. Presently, the most promising and economic method of disposing of the runoff effluent is on cropland. For this reason, we must examine the consequences of continued application of effluent to cropland, and determine if this practice is in any way detrimental or beneficial to soil or subsequent crops being produced on this soil.
In 1971 a two year effluent loading study was initiated to study effects of beef feedlot effluent on forage sorghum yields, and plant and soil chemistry when applied by furrow irrigation. The objectives of the study are as follows:
Compare the production of forage sorghum with irrigation of feedlot runoff effluent, equal irrigations of water, and no irrigation.
Determine the continuing NO3-N and available P levels in the soil.
Determine the NO3-N in the forage crop at harvest.
Determine concentrations of cations (Na, Mg, Fe, Cu, Ca, K, Mn) in the soil solution and in the harvested forage.
Monitor soil pH and electrical conductivity over the two year study.
The study was conducted on the William Cockerill farm, 2 miles west and ½ mile south of Springfield, Nebraska, located in Sarpy County. The farm is the site of a USDA-ARS cooperative research project, studying feedlot waste control systems.
The runoff used for application was captured from a 3.3 acre broad-basin terrace design feedlot system. A series of four lots, three with catch basins, are located on a 5% slope. The cooperator used a stocking rate approximately 400 square feet per head. If weather permitted, runoff collected from these lots was stored in the catch basin for 24 hours to allow the solids to settle. The effluent was then drained to a holding pond and stored until it was applied to the disposal plots.
Disposal plots were established on the flood plain of Buffalo Creek, which meanders 200 yards down slope of the feedlots. This creek served as a supply for the water application. The soil would be classified in the Colo series, and has a silty clay loam texture.
Pioneer 931 was the sorghum variety planted both years. It is primarily a silage crop and is used as a green chop or ensilage feed.
Advisor: L. F. Elliott