|Torbert, Henry - Allen|
|Way, Thomas - Tom|
|Pote, Daniel - Dan|
Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2008
Publication Date: 5/1/2009
Citation: Sistani, K.R., Torbert III, H.A., Way, T.R., Bolster, C.H., Pote, D.H., Warren, J.G. 2009. Broiler Litter Application Method and Runoff Timing Effects on Nutrient and Escherichia coli Losses from Tall Fescue Pasture. Journal of Environmental Quality. 38(3):1216-1223 Interpretive Summary: Over two-thirds of the total U.S. Broiler chicken production is located in the southeastern United States, which is a major segment of the farm economy in the region. Poultry litter is generally surface applied to pastures and hay fields year-round to supply plant nutrients, particularly nitrogen (N) and phosphorus (P). Runoff from litter-applied land has the potential to transport nutrients and pathogenic microorganisms to nearby surface water. Proper land application of animal manure is critical to water quality in watersheds with significant livestock numbers. With regard to permanent pasture systems, inability to incorporate waste materials leads to increased nutrient concentration such as phosphorus, nitrogen, copper, and zinc and pathogenic microorganisms near the soil surface. Currently, broadcasting is a common method of litter application on soil in many parts of U.S. The objectives of this study were (i) to compare the effect of broiler litter application method on nutrient and E. coli losses in runoff from tall fescue pasture in the Appalachian Plateau, and (ii) to determine the impact of antecedent time (time between litter application and the first runoff event) on nutrient and E. coli losses. Inorganic N and E. coli concentrations in runoff were significantly greater from broadcast litter application than subsurface litter application, while fertilizer treatment had runoff with greater NH4-N but smaller NO3-N than litter application treatments. The loss of total phosphorus, NO3-N, and total suspended solids from broadcast litter application was 83.5%, 64%, and 68% greater than subsurface litter application, respectively. About 81% of the runoff total phosphorus concentration was in the form of dissolved reactive phosphorus for both litter-application methods.
Technical Abstract: More than 85% of broiler (chicken, Gallus gallus domesticus) litter applied in the U.S. is being applied to pasture lands year-round. Runoff from litter-applied land has the potential to transport nutrients and pathogenic microorganisms to nearby surface water. Many studies have indicated the advantages of manure incorporation into soil in contrast to broadcast application to reduce nutrient losses; however, incorporation of poultry litter through injection banding into a perennial forage system has not been evaluated. Also, few studies have looked at the effect of manure incorporation on bacterial losses. In this study, we used rainfall simulations to examine the effect of broiler litter application method on nutrient and E. coli losses in runoff from tall fescue pasture in the Appalachian Plateau, to determine the impact of antecedent time on nutrient and E. coli losses in runoff, and to determine the longevity of nutrient losses by successive runoff events from the same plots. Runoff plots were constructed on Hartselle fine sandy loam (Typic Hapludults) soil with permanent ‘Kentucky 31’ tall fescue (Festuca arundinacea) pasture in Crossville, AL. Broiler litter was applied at a rate of 8.97 Mg ha-1 by either broadcast application or by subsurface banding. Additional plots were included which received a broadcast application of commercial fertilizer (19-19-19) applied at a rate of 269 kg N ha-1 corresponding to the N applied with the broiler litter treatment, and the control plots that receive no nutrient additions.