Phosphorus Runoff from Two Common Poultry Litter Treatments Applied at Integrator Rates on No-till Fields.

Often required by poultry industry integrators, sodium bisulfate (PLT) and aluminum sulfate (alum) are the most common litter treatments used in poultry houses to reduce ammonia volatilization below a toxic level to maintain the health of the growing flock.  Previous work has demonstrated that a > 5% alum addition to poultry litter also has additional agronomic and water quality benefits beyond the broiler house by binding phosphorus (P) and keeping it on agricultural fields. We compared the total phosphorus (TP) and 0.45 µm filtered phosphorus (FP) in runoff from PLT and alum treated litter applied at equivalent P-content rates of 154 kg P ha^-1 in no-till corn fields across four physiographic regions with silt loam textured surface soils. Runoff was collected from 2-m² rainfall simulation plots following SERA-17 protocol in a split-block experimental design. Runoff TP from two of the four sites was significantly lower in plots treated with PLT (p value < 0.05) relative to alum treated litter plots.  In all sites FP in runoff from PLT litter treated plots was significantly lower (p value < 0.05) than in alum litter treated plots.  The USDA NRCS recommends application of alum at a rate of 5 – 10%, however the integrator involved in this broiler house where litter was obtained has a low alum application requirement.  Based on the results of this study, the integrator recommended rate is too low to benefit water quality.  Incentives may be necessary to encourage broiler production facilities to increase alum application rates beyond integrator minimum levels.