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United States Department of Agriculture

Agricultural Research Service

Research Project: SOIL APPLICATION OF AGRICULTURAL WASTE TO IMPROVE CROP PRODUCTION SYSTEMS AND ENVIRONMENTAL QUALITY Title: Epic Evaluation of the Impact of Poultry Litter Application Timing on Nutrient Losses

Authors
item Torbert, Henry
item Gerik, T - BLACKLAND RES. & EXT. CTR
item Harman, W - BLACKLAND RES. & EXT. CTR
item Williams, J - BLACKLAND RES. & EXT. CTR
item Magre, M - BLACKLAND RES. & EXT. CTR

Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2007
Publication Date: November 1, 2008
Citation: Torbert III, H.A., Gerik, T.J., Harman, W.L., Williams, J.R., Magre, M. Epic evaluation of the impact of poultry litter application timing on nutrient losses. Communications in Soil Science and Plant Analysis. 39:3004-3033.

Interpretive Summary: Recently, changes in the utilization practices of animal manures for fertilization have been encouraged to reduce the potential of non-point pollution of lakes and streams from agricultural land. However, the potential impact of changing some of these practices have not been fully studied. Computer modeling was used to examine the potential impact on nutrient movement important to water quality from varying poultry litter fertilization times for pastures (both warm and cool season) during winter months on the major soil regions of Alabama. Results indicated that soil type and best management practices such as are administered with the P index are the more important than regional climate differences in Alabama in determining N and P losses to the environment.

Technical Abstract: Recently, changes in the utilization practices of animal manures for fertilization have been encouraged to reduce the potential of non-point pollution of lakes and streams from agricultural land. However, the potential impact of changing some of these practices have not been fully studied. The objective of this study was to examine the potential impact of limiting poultry litter application times on nutrient movement important to water quality. The WinEPIC model was used to simulate poultry litter applications during the winter months and chemical fertilizer application, with both cool season and warm season grass pastures on the major soil regions of Alabama. With the warm season grass, soluble N losses could be reduced if the application of poultry litter was made after December 30. With the cool season grasses, there was no significant difference in application dates for poultry litter for soluble N losses for any soil region, and no improvement could be noted for limiting applications in the Northern Alabama compared to Southern Alabama. No significant difference was observed for soluble P losses for application date for either warm season or cool season grass pastures. This indicates that factors other than plant P uptake during the growing season were the dominate regulators of the amount of soluble P lost in runoff. Also, the results would indicate that best management practices such as are administered with the P index are more important than plant growth factors in determining N and P losses to the environment.

Last Modified: 11/23/2014