Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 10, 2002
Publication Date: November 10, 2002
Citation: DAO, T.H. 2002. ALTERNATIVE TREATMENT TECHNOLOGIES FOR CONTROLLING BIOAVAILABLE PHOSPHORUS IN ANIMAL MANURE. AGRONOMY ABSTRACTS. CD-ROM No A05-dao171859-0.
Animal manure has long been used as an organic source of plant nutrients and organic matter to improve the physical and fertility conditions of agricultural lands. However, repeated applications of manure, often at rates designed to meet crop N requirements, have resulted in a buildup of soil test phosphorus (STP) beyond sufficient levels for optimal crop yields. Both STP and water-extractable P are correlated with P in runoff water and agricultural P presents an added ecological risk in watersheds with impaired water quality. A review of established animal production and manure management approaches indicated that current practices contribute to high levels of water-extractable P in manure. They include dietary inorganic P supplement that is easily excreted in feces, low hydrolytic efficiency and utilization of feed phytate-P, amending feed with exogenous phytases, and waste storage conditions favorable to phosphate dissolution and post-excretion dephosphorylation of organic P. In order to control water-extractable P and potential transport to surface waters, alternative manure treatments and on-farm management practices for manure-amended fields are critically needed to control agricultural P environmental dispersion. Bioavailable P reduction strategies are grouped and discussed as five broad categories. They include physical treatments, chemical additives, structural practices, biofilters, and other biological nutrient reduction methods. As the footprint of animal agriculture increases in scope, a combination of chemical and BNR approaches may be needed to develop integrated solutions to the problem of excess phosphorus in manure.