Zhengxia Dou1, John D. Toth1, Zhihong Xu2, Chengrong Chen2, Sue Boyd2, Andrew Sharpley3, and Christine Wang1. (1) Univ of PA, 382 W Street Rd, Kennett Square, PA 19348, (2) Griffith Univ, Nathan Campus, 170 Kessels Rd, Nathan, Queensland, 4111, Australia, (3) USDA-ARS, Past. Sys. & Mgmt. Res., Curtain Rd, Bldg 3702, University Park, PA 16802-3702
Long-term manure applications with more P than crop uptake result in soil P buildup and can change P chemistry. To assess the impact of long-term manure application on soil P functional groups, we determined P speciation using 31P NMR in 10 soils receiving different kind of agricultural wastes including dairy, swine, or poultry manure or spent mushroom compost for 8-10 years. Soil total P increased by 3 to 5 folds. Much of the increases is orthophosphate. Among organic P, monoester phosphate dominates. Differences in P chemistry among different soils with different type of manure will be discussed.