ARS | Publication request: Effect of Animal Manure on Phosphorus Sorption to Soils

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 23, 2007
Publication Date: November 5, 2007
Citation: Bolster, C.H., Sistani, K.R. 2007. Effect of Animal Manure on Phosphorus Sorption to Soils. ASA-CSSA-SSSA Annual Meeting Abstracts.

Technical Abstract: In most phosphorus (P) sorption studies P is added as an inorganic salt to a pre-defined background solution such as CaCl2 or KCl; however, in many regions the application of P to agricultural fields is in the form of animal manure. The purpose of this study, therefore, was to compare the sorption behavior of dissolved reactive P (DRP) in KH2PO4 amended CaCl2 and KCl solutions with sorption behavior of DRP in three different animal manure extracts. Phosphorus single-point isotherms (PSI) were conducted on eight soils with the following solutions: KH2PO4 amended 0.01 M CaCl2 solution, KH2PO4 amended 0.03 M KCl solution, water extracted dairy manure, water extracted poultry litter, and swine lagoon effluent. PSI values for the dairy manure extract were significantly lower than the CaCl2 solution for all eight soils and lower than the KCl solution for six soils. PSI values were significantly higher, on the other hand, for poultry litter extract and swine effluent than the inorganic solutions in four and five of the soils, respectively. Our observations that the sorption of DRP in manure solutions differs significantly from that of KH2PO4 amended CaCl2 and KCl solutions indicates that manure application rates based on sorption data collected from inorganic P salt experiments may be inaccurate.