Submitted to: International Symposium on Agricultural & Food Processing Wastes Proceeding
Publication Type: Proceedings
Publication Acceptance Date: October 2, 1995
Publication Date: N/A
Interpretive Summary: This research report summarizes the crop use of nitrogen and phosphorus applied to the soil in the form of commercial fertilizer or beef cattle waste. Corn silage was grown on plots fertilized with commercial fertilizer or a combination of commercial fertilizer and manure or fertilizer and composted manure. The silage yields were not changed by the source of either nitrogen or phosphorus. Furthermore, there has been no buildup of either nutrient within the soil under any of the treatments, although there was a small increase of phosphorus near the surface under the heavy application treatments. This study will continue for at least 5 years. There may be a greater increase in nutrient content in the future as the manure and compost do not contain the nutrients in the correct ratio needed by the crop.
This project was initiated in south-central Nebraska in 1993 to evaluate management strategies for beef feedlot manure to efficiently utilize manure-derived nutrients on irrigated cropland. Beef feedlot manure and composted beef feedlot manure were applied to irrigated cropland producing corn forage for silage according to two strategies: to provide approximately the total crop requirement for nitrogen (N) or crop removal of phosphorus (P) with organic source applications. In addition, treatments were applied with or without a winter cover crop of winter rye to serve as an off-season sink for mineralized nutrients. In the first year of the study, forage yield, forage N and P uptake, and soil accumulation of N and P were not substantially influenced by organic source or presence of the cover crop. Forage dry matter yields from organic source treatments were equivalent to commercial fertilizer in both 1993 and 1994. Soil accumulation of P was increased in the surface 0.3 m with treatments receiving organic sources relative to those receiving commercial fertilizer N only. The study is anticipated to be of 5-10 years duration with continuation of each treatment on the same plots.