Manure P fractionation

• Published in: Bioresource technology 1994, Vol.49 (2), p.149-155
• Main Author: Barnett, G.M.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; feces; fractionation; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; inorganic; Manure; organic; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; phosphorus; Soil-plant relationships. Soil fertility. Fertilization. Amendments
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/0960-8524(94)90078-7

The proportion of organic (P o) and inorganic (P i) P in animal wastes affects their value as crop fertilizers. This study was conducted to develop a manure P fractionation method. Samples of beef and dairy cattle manure were lyophilized and ground to pass through a 2-mm screen. The fecal P in these samples was then partitioned into phospholipid (P l), inorganic (P i), acid-soluble organic (P aso) and residual (P r) forms using the McAuliffe and Peech (MP) method. Methods (MP and an Association of Official Analytical Chemists (AOAC) procedure developed for flour), sequential extractions, and grinding size (2 vs 0·25 mm) were compared for fecal P l extraction. The AOAC method removed more P l with less variability and fewer chemicals, required less time than the MP procedure, and had no effect on other P forms. All lipid dry matter was removed in the first ether or ethanol extraction, but not P. More lipid dry matter and P were removed in the first extraction of coarser (2 mm) dairy cattle fecal material than from feces ground finer (0·25 mm). Two beef and one dairy cattle fecal samples contained 6·4, 7·2 and 8·8 mg g −1 of total P (P t) with 50·0, 51·6 and 70·0, as P i, 27·0, 25·3 and 15·9% as P r, 23·0, 22·3 and 12·4% as P aso, and 0·0, 0·8 and 1·7% as P l, respectively. The AOAC flour method can be used to extract fecal P l and the MP procedure to extract P i, P aso and P r forms.