Mark S. Reiter, Eastern Shore AREC, Virginia Tech, Painter, VA, Sara Reiter, Eastern Shore Resource Conservation and Development Council, Melfa, VA and Jane Corson-Lassiter, USDA-NRCS, Accomac, VA
Through replicated field trials conducted at the Virginia Tech Eastern Shore Agricultural Research and Extension Center on the Delmarva Peninsula, this project evaluated the poultry litter pyrolysis co-product (biochar) as a potential source as a phosphorus (P) fertilizer and overall soil amendment for the region's fresh market tomato crop. After pyrolysis, any concerns regarding bacterial contamination in growing fresh vegetables is eliminated, and biochar retains high levels of plant available P, nitrogen, and potassium. We tested biochar in a 2 P source (biochar and inorganic P fertilizer) × 2 P rate (biochar at 4 and 8 tons per acre) factorial arrangement in a randomized complete block design using alpha = 0.10. Plant (yield and plant tissue) and soil measurements (total carbon and Mehlich-1 extractable P, both before and after amendments were applied) were used for treatment comparison. Yield data indicated that farmers must be careful when applying biochar derived from poultry litter. Although previous research signifies an application rate up to 44.8 Mg ha-1, application rates in excess of 9.0 or 17.9 Mg ha-1 caused serious plant injury and yield reduction in fresh market tomato plasticulture productions systems in 2011 and 2012, respectively. More research needs to be completed to fully understand the potentials and problems with using co-products in the marketplace and Mid-Atlantic crop productions systems.