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ARS Home » Midwest Area » Bowling Green, Kentucky » Food Animal Environmental Systems Research » Research » Publications at this Location » Publication #209939
Title: Impact of Soil Type and Application Rate on the Availability of P Applied as Alum-Treated Poultry Litter

Author
item Warren, Jason
item PHILLIPS, STEVEN - VIRGINIA TECH
item MULLINS, GREGORY - NEW MEXICO ST.

Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2008
Publication Date: 10/7/2008
Citation: Warren, J.G., Phillips, S.B., Mullins, G.L. 2008. Impact of Soil Type and Application Rate on the Availability of P Applied as Alum-Treated Poultry Litter. Communications in Soil Science and Plant Analysis. Volume 39, Numbers 17-18, October 2008 , pp. 2515-2533(19)

Interpretive Summary: Interpretive Summary The treatment of poultry litter with alum has been shown to be affective in reducing P availability to surface runoff losses. This reduction in surface runoff P losses results in part from the lower soil test P concentrations which result from the application of alum-treated poultry litter compared to non-treated poultry applications. However, data evaluating the influence of soil type and application rate on the effectiveness of this management practice in minimizing soil test P is not available. Therefore a laboratory incubation experiment was conducted in which two alum-treated poultry litters and a non-treated poultry litter were applied to three soils. These litter sources and an inorganic P source was applied at rates of 66, 132, and 197 mg P kg-1 with a 0-P check treatment included for each soil. Soils were incubated for 1 year and samples were collected at 1, 3, 6, and 12 months after treatment application. Results indicated that alum-treated poultry litter applications generally reduced P availability compared to non-treated poultry litter; this effect was most significant at 1-month after application. The differences between alum-treated poultry litter treatments and non-treated poultry treatments declined with time. In fact, at 12-months significant differences in extractable P between non-treated poultry litter and alum-treated poultry litter treatments were limited at the 66 mg P kg-1 rate. This resulted from a continuous decline in the extractability of P applied in the NPL, whereas the extractability of P applied in the ATPL source changed little with time and in some cases increased slightly between the 1 and 3 month sampling periods. Data collected also showed that application of alum-treated poultry litter were more affective in minimizing P availability in soils with low P sorption capacities than when applied to soils with high P sorption capacities. This occurred because soils with relatively high P sorption capacities are capable of adsorbing the large portion of the soluble P applied in non-treated poultry litter. This adsorption results in minimal increase in soils test P above that found in the 0-P check treatment and therefore limited differences between alum-treated poultry litter treatments and non-treated poultry litter treatments, particularly at low application rates.

Technical Abstract: The purpose of this laboratory incubation study was to assess the solubility of P in alum-treated poultry litter (ATPL) when applied to three Virginia soils at equivalent P-based rates. Three poultry litter sources; one that had received no alum additions and two that had received alum additions were utilized in the study. These litter sources and KH2PO4 were applied at rates of 66, 132, and 197 mg P kg-1 with a 0-P check treatment included for each soil. Soils were incubated for 1 year and samples were collected at 1, 3, 6, and 12 months after treatment application. Data collected was used to calculate the relative extractability of P applied in the three litter sources. Results indicated that ATPL applications reduced P solubility compared to non-treated poultry litter (NPL); this effect was most significant at 1-month after application. However, at 12-months significant differences in extractable P between NPL and ATPL treatments were limited at the 66 mg P kg-1 rate. This resulted from continuous decline in the extractability of P applied in the NPL, whereas the extractability of P applied in the ATPL source changed little with time and in some cases increased slightly between the 1 and 3 month sampling periods. Calculated values of relative extractability were found to be influenced not only by litter source but also P application rate, soil type, and incubation time. Therefore use of relative extractability values as P source coefficients should be done with caution, because experimental protocol can have profound impacts on their magnitude.