ARS | Publication request: Assessing Lability of Phosphorus Forms in Biosolids by Sequential Fractionation and Phosphatase Hydrolysis

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 28, 2008
Publication Date: July 13, 2008
Citation: He, Z., Honeycutt, C.W., Toor, G.S., Haggard, B.E., Zhang, H., Dou, Z. 2008. Assessing Lability of Phosphorus Forms in Biosolids by Sequential Fractionation and Phosphatase Hydrolysis. Plants and Soils, Montreal '08. pg. 45-46.

Technical Abstract: Biosolids may contain a significant amount of phosphorus (P). However, bioavailability of biosolid P is related not only to total P content but also to particular P forms. We examined the P forms in biosolids by sequential fractionation coupled with enzymatic hydrolysis. Biosolid P was found in the four fractions in the following order: H2O<0. 5 M NaHCO3<0.1M NaOH<1 M HCl. Organic P was present in the extracts in different forms, mostly as unhydrolyzable P. In the H2O and NaHCO3 fractions, phytate P (45 and 221 mg P kg-1 of dry matter, respectively) was greater than simple monoester P (35 and 88 mg P kg-1 of dry matter, respectively). In the NaOH and HCl fractions, the distribution was different with less phytate P (117 and 186 kg-1 of dry matter, respectively) than simple monoester P (342 and 1543 kg-1 of dry matter, respectively). Polynucleotide-like P was rarely detected in all four fractions. Results from this study may aid in correct interpretation of P lability in biosolid amended soils and help in assessing the true fate of P from biosolids.