title: Laboratory characterization of phosphorus in fresh and oven-dried organic amendments.
abstract: This study was performed to determine the forms of P and to examine the influence of oven-drying on P forms in different organic amendments. Samples of biosolids, beef and dairy cattle manures, and hog manures from sow and nursery barns were used in this study. Both fresh and oven-dried amendments were analyzed for inorganic (Pi), organic (Po), and total phosphorus using a modified Hedley fractionation technique. Water extracted about 10% of total biosolids P and 30 to 40% of total hog and cattle manure P. The amount of P extracted by NaHCO3 ranged from 21 to 32% of total P in all organic amendments except in the dairy cattle manure with 45% of total P. The labile P fraction (sum of H2O- and NaHCO3-extractable P) was 24% of biosolids P, 60% of hog manure P, and 70% of dairy cattle manure P. The residual P was about 10% in biosolids and cattle manures and 5 to 8% in hog manures. Oven-drying caused a transformation in forms of P in the organic amendments. In hog manures, H2O-extractable Po was transformed to Pi, while in the dairy manure NaHCO3-extractable P was converted to H2O-extractable Pi with oven-drying. Therefore, caution should be exercised in using oven-drying for studies that evaluate forms of P in organic amendments. Overall, these results indicate that biosolids P may be less susceptible to loss by water when added to agricultural land.
authors.affiliation: Department of Soil Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Ajiboye
authors.forename: O O
authors.initials: OO
authors.lastname: Akinremi
authors.forename: G J
authors.initials: GJ
authors.lastname: Racz
mesh_terms: D000383:Agriculture; D000818:Animals; D002417:Cattle; D005308:Fertilizers; D006358:Hot Temperature; D008372:Manure; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*; D013552:Swine; D014867:Water; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D005308:Fertilizers; D008372:Manure; D012987:Soil; D012989:Soil Pollutants; D014873:Water Pollutants; D014867:Water; D010758:Phosphorus