Comparison of Nucleus O-Phos™ Versus Standard Phosphorus Fertilization of Sweet Corn Grown on an Everglades Agricultural Area Histosol: Effects on Yield and Drainage Water Quality.

The Everglades Agricultural Area (EAA) is a 283,000 hectare farming basin comprised of Histosols that is located in the southern third of the state of Florida, USA. The EAA is a major producer of sugarcane as well as the nation’s main producer of spring, fresh market sweet corn.  Drainage water from the EAA basin is discharged to the downstream Water Conservation Areas, Everglades National Park , or the South Florida coastal estuaries. Reducing Phosphorus (P) runoff in water that exits the EAA basin and flows downstream is a critical factor for Everglades’ restoration. Phosphorus fertilization practices that reduce application rates while maintaining or increasing crop yields are key to agricultural sustainability and Everglades’ restoration. This two-year study was conducted in field plot lysimeters to compare the effects of Nucleus O-PHOS™ versus standard fertilizer applications on sweet corn yield and drainage water P concentration. Nucleus O-Phos 8-24-0 is a 100% ortho-phosphate based liquid fertilizer with a neutral pH and chelated iron. The design was a completely randomized single factor experiment with two fertilizer treatments: 1) Nucleus O-PHOS™ (8-24-0) applied at 37 liters ha^-1 plus standard (11-37-0) at 240 liters ha^-1 and 2) standard liquid fertilizer of 11-37-0 applied at 374 liters ha^-1. Results presented include yield parameters and drainage water P speciation concentrations. No statistical yield differences were found for the first year (881 crates ha^-1); yields were higher in year two for O-PHOS compared to standard fertilization (1168 vs 1091 crates ha^-1). Drainage water P concentrations were not different the first year; in the second year drainage water total P concentrations averaged 16% less for O-PHOS than standard fertilizer.  Further research is needed to verify that Nucleus O-PHOS™, recommended as a lower rate P liquid fertilizer, yields better drainage water quality from vegetable production on South Florida Histosols.