Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/5/2000
Publication Date: 11/9/2000
Technical Abstract: In many regions dominated by animal-based agriculture, land application is the most economically viable alternative to utilize manure and manure by-products. Use of solid manures as a nutrient source for dryland crops in semiarid environments is hampered because incorporation reduces the residue cover, thereby increasing evaporative water losses and soil erosion. Alternatively, manure that is spread and left unincorporated will elevate soil phosphorus levels near the soil surface and increase the likelihood of excessive P losses into surface waters. We initiated a study in 1996 to investigate the effects of surface-applied stockpiled and composted beef manure and tillage on soil phosphorus and crop uptake within a wheat-sorghum-fallow dryland crop rotation. Stockpiled and composted beef cattle feedlot manures were applied prior to sorghum planting to supply N or P needs of sorghum and wheat over a 3-year period. Phosphorus-based manure or compost treatments received supplemental urea. Unfertilized and fertilized (urea + superphosphate) checks were also included in the study. Tillage and fertilizer affects on total and extractable soil P, crop yield, and apparent crop recovery of P is presented.