title: Biogenic phosphate minerals in manure: implications for phosphorus loss to surface waters.
abstract: Phosphorus (P) is present in waterways throughout the United States at concentrations that impair water quality. Agriculture, particularly livestock production, has been identified as a major cause of this impairment Excess manure P applied to croplands has increased P losses in runoff, leading to surface water eutrophication. We conducted a long-term (36-week) incubation with poultry and dairy manures applied to a silt loam soil to elucidate mechanisms controlling manure P loss to water. Manures were applied to supply the same total P rate to soils with different antecedent plant-available P concentrations (soil test P). There was a strong synergistic effect between dairy manure and soil test P on water extractable P, while soil test P did not affect P loss from poultry manure-amended soils. Using scanning electron microscopy and energy dispersive X-ray spectroscopy, we found that poultry manure contained sparingly soluble calcium and magnesium phosphate minerals that controlled soil solution P concentrations, while dairy manure did not These minerals resemble other biogenic phosphate minerals. Our findings refute current assumptions that all manure P behaves similarly in soils and that organic forms control manure-soil P loss to water.
authors.affiliation: Department of Soil Science, University of Wisconsin, 1525 Observatory Drive, Madison, Wisconsin 53706, USA. lrcooperband@facstaff.wisc.edu
authors.forename: Leslie R
authors.initials: LR
authors.lastname: Cooperband
authors.forename: Laura Ward
authors.initials: LW
authors.lastname: Good
mesh_terms: D000383:Agriculture; D000818:Animals; D005068:Eutrophication; D008372:Manure; D008855:Microscopy, Electron, Scanning; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry*; D011200:Poultry; D012989:Soil Pollutants / Q000032:analysis*; D013057:Spectrum Analysis; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D008372:Manure; D012989:Soil Pollutants; D014873:Water Pollutants; D010758:Phosphorus