Submitted to: Biology and Fertility of Soils
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2011
Publication Date: 4/10/2011
Citation: Waldrip, H.M., He, Z., Erich, S. 2011. Effects of poultry manure amendment on soil phosphorus fractions, phosphatase activity, and phosphorus uptake. Biology and Fertility of Soils. 47:407-418. Interpretive Summary: Plants can derive their phosphorus (P) from various sources. Poultry manure (PM) contains a large amount of P, and adding this manure to soil can impact the availability of native soil P to plants. To investigate the effects of PM on soil P availability, we grew ryegrass in greenhouse pots amended with poultry manure. Plants and soils were sampled at 4, 8, and 16 weeks after manure application. We found that P added in manure was generally available for plant uptake, and that adding manure stimulated that availability from soil. Additional research may be needed to verify these observations under field conditions.
Technical Abstract: Poultry manure (PM) contains a large amount of P, and adding this manure to soil can impact the availability of native soil P to plants. To investigate the effects of PM on soil P availability, we grew ryegrass (Lolium perenne) in greenhouse pots amended with poultry manure. Biomass was harvested at 4, 8, and 16 wk following PM application, with soil separated into rhizosphere and bulk fractions. Soil was sequentially extracted by H2O, 0.5 M NaHCO3, 0.1 M NaOH and 1 M HCl, and inorganic P (Pi) and enzymatically hydrolysable organic P (Poe) were quantitated. Root P concentrations were 37% higher and total P uptake 59% higher with PM application. At week 16 there was 30% more labile-Pi in the rhizosphere with PM than in unamended soil. Phosphodiesterase activity increased with PM application. Furthermore, acid phosphomonoesterase, alkaline phosphomonoesterase and phosphodiesterase activities were all higher in the rhizosphere than bulk soil at week 16 with PM, indicating that increased labile-P was due primarily to stimulation of soil phosphatase to mineralize NaOH-Poe. Soil pH increased with PM application and plant growth, and was important in promoting P availability by decreasing sorption of Al- and Fe-associated inorganic and organic phosphates. These results demonstrate that whereas PM application may initially increase NaOH and HCl-Pi, these fractions can be readily changed into labile-P and do not necessarily accumulate as stable or recalcitrant P in soil.