Submitted to: International Conference on Plant Nutrition
Publication Type: Proceedings
Publication Acceptance Date: 6/1/2005
Publication Date: 9/14/2005
Citation: He, Z., Honeycutt, C.W., Senwo, Z.N., Tazisong, I.A. 2005. Impacts of long-term poultry litter application on soil phosphorus. International Conference on Plant Nutrition. Sept 2005; pg 910-911 Interpretive Summary:
Technical Abstract: Animal manure is a valuable source of plant nutrients. In this study, sequential fractionation and phosphatase hydrolysis were used to monitor changes in inorganic P (Pi), enzymatically hydrolyzable organic P (Peo), and nonhydrolyzable organic P (Pno)in soil receiving long-term applications of poultry litter (PL). Inorganic P in both H2O and NaHCO3 fractions increased with increased history of application. Contents of stable Pi extracted by NaOH and HCl increased to maximum levels after 10- to 15-years of PL application. Concentration of Peo in the NaOH fraction was higher in soil without PL than in soil receiving PL, and did not change over time. Pno in this fraction increased from none in the soil without PL to 82 mg kg-1 dry soil with 5-year PL, and subsequently fluctuated between 83 and 32 mg kg-1 dry soil in soils with longer application histories. All organic P in the HCl fractions was enzymatically hydrolyzable. This study indicates that repeated application of PL to soil increases the pools of both labile and stable P, but the stable (hydroxide and acid extractable) P is eventually transformed to labile (water and bicarbonate extractable) P, rendering it available for plant uptake. This research may contribute to more effective P management of soils receiving long-term PL applications.