Impacts of Dietary Modification in Animal and Manure Sources on Total P, Water Soluble P, Acid Soluble P, and Organic forms of P.

Impacts of Dietary Modification in Animal and Manure Sources on Total P, Water Soluble P, Acid Soluble P, and Organic forms of P.

Phosphorus loss from soils fertilized with animal manures has been implicated in the degradation of water quality. Management practices, aimed at reducing P loss from animal manure applications, should incorporate the impact of dietary modification and manure sources on P loss in the environment. The objectives of this study were to determine how dietary modification in animal feed and manures from different sources (dairy, swine, and poultry) impact total P, water soluble P, acid soluble P, and organic forms of P in manure samples. Water soluble P and acid soluble P extracts were analyzed by the molybdate blue method (Murphy and Riley, 1962), whereas total P was determined by digesting manure samples with nitric and perchloric acid before being analyzed by ICP-AES. Different forms of organic P in manure samples were assayed using ion chromatography. The results and implications of this study will be presented in this poster.