Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 20, 1997
Publication Date: N/A
Technical Abstract: Land applications of stockpiled and composted livestock manure are made to meet N requirements of the vegetation. The imbalance of N to P in animal manure leads to overapplication of P. High P loading may result in increased P concentrations in runoff, subsurface movement of organic P and zinc deficiency in agricultural plants. Co-applications of agricultural and non-hazardous industrial by-products potentially reduce excessive amounts of P on manure-amended soils. The effects of adding alum, caliche, or fly ash on P concentrations in stockpiled and composted feedlot manure were determined. Amendments were added at rates of .10, .25, and .50 g g**-1 and the mixtures were incubated at 4, 20, and 35C at 60% water- holding capacity. Bray1-P was suppressed by alum and fly ash. Fly ash also decreased Mehlich III-P concentrations, ranging from 30 to 98% in stockpiled and composted manure with increasing amendment rates. The joint tuses of animal manure and non-toxic industrial by-products as co-amendment reduce losses of soluble P and thus may decrease the ecological risks of surface applications of feedlot wastes on crop and rangelands.