Nutrient Availability from Poultry Litter ASH Co-Products.

NUTRIENT AVAILABILITY FROM POULTRY LITTER ASH CO-PRODUCTS Amanda J. Middleton1 and Mark S. Reiter1 1Virginia Tech Eastern Shore Agriculture Research and Extension Center, Painter, VA 23420 ABSTRACT Phosphorus (P) is a nutrient of concern in the Chesapeake Bay watershed due to nutrient imbalances in areas with confined animal feeding operations. By converting poultry litter to an ash via combustion, nutrients are concentrated and are economical to ship out of nutrient surplus watersheds to nutrient deficient regions, such as the corn-belt. We initiated a study on Bojac sandy loam soils to test P availability from poultry litter ash (PLA) on corn. Four PLA products, derived from different sources using different combustion techniques, and 2 biochar products were surface broadcast applied at 3 P rates (22, 44, and 88 kg P2O5 ha-1). Poultry litter co-products were compared to a no-fertilizer control and inorganic P (triple super phosphate; TSP) fertilizer at similar rates. Yield, Mehlich-1 extractable soil nutrients, plant tissue and grain samples, and organic matter content were used to compare treatments. For yield, plant tissue, and grain samples, there was no significant interaction between P source and P rate and the P source main effect was not significant; therefore, all P sources equally supplied P to the corn crop. Yield increased in a linear relationship with P rate (yield = 9.3P + 4137; R2 = 0.98) as did tissue (%P earleaf = 0.0006P + 0.2313; R2= 0.57) and grain samples (%P grain= 0.0007P + 0.244; R2= 0.7621). Mehlich-1 soil extracts indicated that the source of P was also not significant and soil concentrations increased in a linear relationship as P rate increased (Soil P= 0.0771P + 3.5722; R2= 0.87). Soil organic matter had no significant differences with PLA and biochars applied on a P-basis within a single application year. In conclusion, based on preliminary data the PLA and biochar sources derived from PL are suitable and comparable P fertilizer sources for corn on sandy loam soils in the Mid-Atlantic. 1