Submitted to: Animal, Agricultural and Food Processing Wastes Symposium
Publication Type: Proceedings
Publication Acceptance Date: January 15, 2003
Publication Date: October 11, 2003
Citation: He, Z., Honeycutt, C.W. 2003. Evaluation of organic phosphorus in animal manure by orthophosphate releasing enzymatic hydrolysis. In: Burns, R. (editor). 9th International Symposium on Animal, Agricultural and Food Processing Wastes Symposium (ISAAFPW 2003), October 11-14, 2003, St. Joseph, Michigan. Raleigh, North Carolina. p. 542-555. Technical Abstract: The chemical composition of phosphorus in manure significantly impacts its transport and potential bioavailability. As much as 50% of the phosphorus in animal manure is present in organic forms (Po). We explored the possibility of using phosphatase enzymes for characterizing manure Po. We applied acid phosphatase from potato, acid phosphatases from potato and wheat germ, and both phosphatases plus nuclease P1 to identify and quantify simple monoester P, phytate-like P, and polynucleotide-like P, respectively. Animal manures were first sequentially fractionated into water-, NaHCO3-, and NaOH-soluble P. In 11 dairy manures, phytate-like P was present as the major hydrolysable Po in all three fractions. Its concentration in the H2O fraction was positively related to total manure P. However, the concentration in the NaHCO3 and NaOH fractions was more correlated, respectively, to the NaHCO3 - or NaOH-extracted Po. We also investigated the change in manure P distribution after 1 yr storage at 4 oC (swine manure) and 20 oC (cattle manure) using enzymatic hydrolysis. Our data indicate that the amounts of bioavailable P (Pi and enzyme hydrolysable Po) in these manures remained relatively constant during storage. Soluble but enzymatically nonhydrolysable Po, however, increased significantly. Our study demonstrates that enzymatic hydrolysis is an effective approach to identify and quantify hydrolysable Po in animal manure.