Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2015
Publication Date: 11/16/2016
Citation: Waldrip, H., Pagliari, P.H., Harmel, R.D., He, Z., Cole, N.A. 2016. Legacy phosphorus in calcareous soils: Effects of long-term poultry litter application [abstract]. In: ASA-CSSA-SSSA Annual Meeting. Environmental Implications of Using Poultry Litter in Agriculture. November 18, 2015, Minneapolis, MN. 388-1.
Technical Abstract: The effect of manure application on soil phosphorus has been intensively studied with modifications of the Hedley sequential fractionation procedure, X ray absorption near edge structure spectroscopy, and 31P nuclear magnetic resonance. Modern sequential fractionation techniques, coupled with phosphatase hydrolysis, have recently allowed for greater understanding of manure effects on soil phosphorus distribution. We evaluated the effect of long-term (greater than 10 years) poultry litter (broiler and turkey litter) application (4.5, 6.7, 9.0, 11.2, and 13.4 Mg manure ha) on phosphorus in watershed scale plots (cultivated and grazed/ungrazed pasture) near Riesel, Texas. Soil inorganic phosphorus (Pi) and organic phosphorus (Po) were quantified by sequential extraction (H2O, NaHCO3, NaOH, and HCl) and hydrolysis with acid phosphomonoesterase, nuclease P1, and 3 phytase (Pe). Litter application increased the total extractable phosphorus (Pt) in all plots, regardless of land use type; application at 13.4 Mg ha increased Pt in cropland and pasture by 23 and 8 fold, respectively. Compared to control, H2O Pi from litter amended plots increased by 9 to 34 fold (cultivated), and 7 to 30 fold (pasture), indicating substantial risk of soluble phosphorus runoff. Most labile Po (extracted with H2O and NaHCO3) was monoester like, and decreased in the order of monoester greater than nucleic acid greater than phytate greater than non hydrolysable organic phosphorus (Pne). Litter application did not affect NaOH Pi or NaOH Pe (P greater than 0.05), but increased NaOH Pne: the general composition was Pi greater than monoester greater than phytate greater than nucleic acid greater than Pne. An average of 68% of Pt was extractable with HCl. The HCl P composition was predominantly (95%) Po, and increased 2 to 3 fold by high rates of litter application in cultivated and grassed plots, respectively. Only trace levels of HCl Pe were found; however, litter application increased HCl Pne by 1 to 3 fold. Thus, repeated litter application increased levels of both soluble Pi and stable, non hydrolysable Po, but specific response varied with application rate and land management.