Adoption of the 333 Amending Soil Properties with Gypsum Products Conservation Practice Standard in the State of Alabama.

Alabama is the second largest poultry producing state in the US and large amounts of poultry litter are applied to crop fields, hayfields and pastures. The soils of these farms are already showing high levels of phosphorus, and during storm events when significant runoff is generated, the phosphorus will leave these fields in sediment with soil erosion or as dissolved phosphorus entering our surface waters and causing water quality degradation.

There is a wide range of research data confirming that gypsum applications are reducing the phosphorus solubility in soils, and that crop fields with elevated P levels could benefit from gypsum applications by hanging onto more phosphorus and reducing the negative environmental impacts to neighboring surface waters.

The larger Alabama poultry producers are regulated by the state environmental agency and required to submit a nutrient management plan showing no significant P runoff from the application fields determined by the Alabama Phosphorus Index tool. The Alabama NRCS Agronomy Technical Note #72, Phosphorus Index for Alabama, gives credit for gypsum treatment as a reduction factor to phosphorus transport risk.

Alabama NRCS would like to see more state-based research on the effects of gypsum applications to water infiltration and phosphorus solubility to further define our Phosphorus Index tool to properly credit this conservation practice during nutrient management planning.