Effects of gypsum-amended poultry litter on nutrient release and runoff from a hayfield

Authors: POWELL, A - Auburn University; PRASAD, R - Auburn University; Watts, Dexter; CHAKRABORTY, D - Auburn University; Torbert, Henry - Allen

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/4/2021
Publication Date: 11/7/2021
Citation: Powell, A., Prasad, R., Watts, D.B., Chakraborty, D.B., Torbert III, H.A. 2021. Effects of gypsum-amended poultry litter on nutrient release and runoff from a hayfield [abstract]. ASA, CSSA, SSSA International Annual Meeting, Nov. 7-10, 2021, Salt Lake City, UT.

Interpretive Summary:

Technical Abstract: The United States is the largest producer of broilers and two thirds of U.S. broilers are grown in the southeastern region. Poultry litter (PL) is a highly valuable fertilizer and is often land applied to hayfields. However, nutrient losses in runoff from the fertilized fields are a major concern for surface water quality. Water soluble phosphorus (WSP) is of particular concern, as it is readily lost and can drive surface water eutrophication. Previous studies have shown that when gypsum is top dressed to land applied poultry litter, WSP runoff concentrations and loads were reduced compared to litter alone. The objective of this study is to determine how poultry litter bedding management effects nutrient losses when land applied to a hayfield. A rainfall simulation was conducted in Camp Hill, AL at the Piedmont Agricultural Substation to determine the effect of litter bedding material (gypsum, PLT, shavings) on nutrient runoff losses after land application. Litter was applied immediately before the first simulation and a second rainfall simulation was conducted 6 weeks later. Runoff water samples were collected at the time of initial runoff and subsequent samples were taken at ten minute intervals up to 40 minutes of runoff. The water samples were analyzed for orthophosphate, ammonium, and nitrate according to standard procedures. When gypsum was used as bedding material, orthophosphate runoff load was reduced compared to the industry standard bedding (PLT). Nitrate loads for all litter treatments were significantly lower than the control (unfertilized). However, the gypsum litter treatments had higher ammonium loads than litter alone. Water soluble phosphorus concentrations and loads were reduced by gypsum treated litter compared to the industry standard bedding treatment and litter only bedding.