Title:
Using the Georgia P-Index to identify high risk management of poultry litter

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Author(s)
Gaskin, Julia W.
Harris, Keith
Cabrera, Miguel L.
Risse, L. Mark
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Advisor(s)
Advisor(s)
Editor(s)
Hatcher, Kathryn J.
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Abstract
The Georgia P Index was developed as a tool to evaluate the risk of bioavailable P loss in fields under various management practices. We compared the results of the P Index with four years of data from 1.5 m by 4.6 m bermudagrass plots fertilized with poultry litter at 8.9 Mg ha-1 (recommended rate); poultry litter at 17.9 Mg ha-1; composted poultry litter, poultry litter with alum, commercial fertilizer; and a control (no amendments). P Index ratings above 75 indicate high risk where management should be changed. The P Index indicated management changes would be needed for the 17.9 Mg ha-1 treatment during all 4 years, for composted PL during year 4, and for PL with alum during years 3 and 4. The P Index did not indicate management changes were necessary using the recommended rate of 8.9 Mg ha-1 after 4 years of application; however, volume-weighted P concentrations in the 8.9 Mg ha-1 treatment were double the control concentrations during years 3 and 4. The comparison indicates that the P Index does identify high risk management practices under the conditions of this study.
Sponsor
Sponsored by: Georgia Environmental Protection Division U.S. Geological Survey, Georgia Water Science Center U.S. Department of Agriculture, Natural Resources Conservation Service Georgia Institute of Technology, Georgia Water Resources Institute The University of Georgia, Water Resources Faculty
Date Issued
2005-04
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Text
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Proceedings
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