Phosphorus dynamics from broiler breeder diets in manure, soil, and corn.

摘要

Studies of broiler breeder diet modifications to reduce phosphorus (P) excretion have evaluated bird performance, but no studies have quantified the effects of P in the manure and the impacts to soil and plant availability once soil-applied. Four diets were formulated by factoring two levels, 0.40 and 0.22% available P (NRC, Low, respectively), with or without phytase during the breeder laying phase (wk 22 to 64). Breeders fed phytase produced manures with 15% lower total P concentration, but did not change manure water-soluble P (WSP). However, P in the breeder manures was >92% orthophosphate. The incubation of the four unique manures in samples of Portsmouth (Typic Umbraquult) and Wagram (Arenic Kandiudult) series generally did not differ in concentrations of Mehlich-3 P, soil WSP, total inorganic P, and total P. Phosphorus-based applications of breeder manures (NRC, Low) and triple superphosphate (TSP, Ca[H2PO4]2 H2O) were applied to a P-deficient, Portsmouth soil in the greenhouse to determine the response of corn (Zea mays). Corn growth was equal among P sources in the initial study, but it tended to be greater in the soils amended with breeder manures in the residual study due to the P applied and the apparent liming effect of the soil. The NRC and Low breeder manures were applied at 39 kg P ha-1 in 2007 at Salisbury (Typic Rhodudult), Lewiston (Aquic Paleudult), and Plymouth (Typic Umbraquult), which ranged in soil P levels. Plymouth included TSP and an untreated control. Corn growth was equal among soils amended with the breeder manures NRC and Low in all site-years and grain P removal was equal five out of six site-years. Grain production, grain P removal, and applied P recovery were equal among P sources in 2007, but the breeder manure treatments were greater than TSP in 2008. Breeder manures should be considered equivalent to TSP in P impacts to the soil and plant availability.