TY - JOUR
T1 - Evaluating the influence of storage time, sample-handling method, and filter paper on the measurement of water-extractable phosphorus in animal manures
AU - Baum, Kristen
AU - Pierzynski, Gary
AU - Kleinman, Peter
AU - Kovar, John
AU - Maguire, Rory
AU - Moore, Philip
AU - Zhang, Tiequan
PY - 2006
Y1 - 2006
N2 - Surface-applied manures create a potential phosphorus (P) runoff hazard, especially when unincorporated. In such cases, the concentration of water-extractable P in the manure has been correlated to soluble P concentrations in runoff. This study evaluated the influence of holding time, sample-handling procedure, and filtration method on measurement of the water-extractable P content of manures in a 3 x 3 x 2 factorial arrangement of treatments. A two-way interaction between holding time and sample-handling procedure occurred for most samples. Six samples had water-extractable P concentrations that were less than or equal to dried and dried/ground treatments. Only one sample had higher water-extractable P concentrations for fresh than for dried and dried/ground treatments. When significant differences occurred as a result of the filtration method, results for Whatman No. 40 filters, with a larger pore size than 0.45 μm nitrocellulose membranes, were usually higher. There was no significant difference in the coefficient of variation across sample-handling procedures, suggesting that efforts to dry and/or grind samples were not needed. These results support the adoption of a standardized protocol for measuring water-extractable P in manures that represents the appropriate balance between the ease of implementation and the strength of the correlation to P runoff concentrations.
AB - Surface-applied manures create a potential phosphorus (P) runoff hazard, especially when unincorporated. In such cases, the concentration of water-extractable P in the manure has been correlated to soluble P concentrations in runoff. This study evaluated the influence of holding time, sample-handling procedure, and filtration method on measurement of the water-extractable P content of manures in a 3 x 3 x 2 factorial arrangement of treatments. A two-way interaction between holding time and sample-handling procedure occurred for most samples. Six samples had water-extractable P concentrations that were less than or equal to dried and dried/ground treatments. Only one sample had higher water-extractable P concentrations for fresh than for dried and dried/ground treatments. When significant differences occurred as a result of the filtration method, results for Whatman No. 40 filters, with a larger pore size than 0.45 μm nitrocellulose membranes, were usually higher. There was no significant difference in the coefficient of variation across sample-handling procedures, suggesting that efforts to dry and/or grind samples were not needed. These results support the adoption of a standardized protocol for measuring water-extractable P in manures that represents the appropriate balance between the ease of implementation and the strength of the correlation to P runoff concentrations.
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U2 - 10.1080/00103620500449328
DO - 10.1080/00103620500449328
M3 - Article
AN - SCOPUS:32644480819
SN - 0010-3624
VL - 37
SP - 451
EP - 463
JO - Communications in Soil Science and Plant Analysis
JF - Communications in Soil Science and Plant Analysis
IS - 3-4
ER -