|Franklin, Dorcas - Dory|
Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/6/2005
Publication Date: 11/6/2005
Citation: Tassistro, A., Zhao, Y., Cabrera, M.L., Xia, K., Franklin, D.H., Kissel, D. 2005. Buffer extractable phosphorus from broiler litter and layer manure [abstract]. ASA-CSSA-SSSA International Meetings, November 6-10, 2006, Salt Lake City, Utah. CDROM.
Technical Abstract: Aqueous suspensions of poultry manure are usually alkaline. Previous research has shown that the top 1.0-cm of soils and the thatch of pastures in NE Georgia have a pH around 6, and that broiler litter pH decreases to soil/thatch values within a month after its application. Because phosphate solubility increases with acidification, determining soluble P at an alkaline pH may underestimate what would be released after manure land application. The objective of this study was to find suitable buffers for P extraction from poultry manure at pH 6. Samples of four broiler litters and two layer manures with contrasting P contents were selected. Molybdate reactive phosphorus (MRP) and dissolved un-reactive phosphorus (DUP) were determined in extracts obtained with de-ionized water, de-ionized water at pH 3, 4, 6, and nine 0.1 M buffers with pH 6. The pH of the de-ionized water-manure suspension was adjusted with 0.5N HCl. The concentrations of MRP and DUP at pH < 6 were markedly higher than that in de-ionized water extractions without acidification (pH = 8). Of the nine buffers evaluated, ethanesulphonic acid (MES) was the most promising buffer because its results were comparable to those obtained with HCl-acidified de-ionized water.