TY - JOUR
T1 - Developing an environmental manure test for the phosphorus index
AU - Kleinman, Peter J.A.
AU - Sharpley, Andrew N.
AU - Wolf, Ann M.
AU - Beegle, Douglas B.
AU - Elliott, Herschel A.
AU - Weld, Jennifer L.
AU - Brandt, Robin
PY - 2006
Y1 - 2006
N2 - Widespread implementation of the phosphorus (P) index has focused attention on environmental manure tests that can be used to estimate the relative availability of P in manure to runoff water. This article describes the development and use of a water extractable P (WEP) test to assess the capacity of land-applied manure to enrich P in runoff water. WEP of surface-applied manure has been shown to be strongly correlated to dissolved P concentrations in runoff from agricultural soils. WEP tests that have a defined water-to-manure-solids ratio and involve extraction times of 30 to 120 min provide the best prediction of dissolved P in runoff across a wide range of manures. Consistent measurement of manure WEP can be achieved with manure sample storage times of up to 22 days (4°C), acidified extract holding times of 18 days, and solid separation by either centrifugation or paper filtration. Reproducibility of WEP tests is comparable to that of other common manure tests (e.g., total P), as verified by within-laboratory and inter laboratory evaluations. A survey of 140 livestock manures revealed significant differences in mean WEP among different livestock manures, with swine greater than poultry (turkey, broiler and layer chickens) and dairy cattle greater than beef cattle. Such results support the use of WEP-based coefficients to modify the source component of the P index.
AB - Widespread implementation of the phosphorus (P) index has focused attention on environmental manure tests that can be used to estimate the relative availability of P in manure to runoff water. This article describes the development and use of a water extractable P (WEP) test to assess the capacity of land-applied manure to enrich P in runoff water. WEP of surface-applied manure has been shown to be strongly correlated to dissolved P concentrations in runoff from agricultural soils. WEP tests that have a defined water-to-manure-solids ratio and involve extraction times of 30 to 120 min provide the best prediction of dissolved P in runoff across a wide range of manures. Consistent measurement of manure WEP can be achieved with manure sample storage times of up to 22 days (4°C), acidified extract holding times of 18 days, and solid separation by either centrifugation or paper filtration. Reproducibility of WEP tests is comparable to that of other common manure tests (e.g., total P), as verified by within-laboratory and inter laboratory evaluations. A survey of 140 livestock manures revealed significant differences in mean WEP among different livestock manures, with swine greater than poultry (turkey, broiler and layer chickens) and dairy cattle greater than beef cattle. Such results support the use of WEP-based coefficients to modify the source component of the P index.
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U2 - 10.1080/00103620600817242
DO - 10.1080/00103620600817242
M3 - Article
AN - SCOPUS:33746420178
SN - 0010-3624
VL - 37
SP - 2137
EP - 2155
JO - Communications in Soil Science and Plant Analysis
JF - Communications in Soil Science and Plant Analysis
IS - 15-20
ER -