Agri-Environmental Assessment of Pelletized Poultry Litter in Corn Production: Field Studies.

The geographic intensification of poultry production in Delaware has resulted in farm and watershed-scale nutrient surpluses, high phosphorus (P) soils, and contributed to the impairment of surface and ground waters. This has led to concerted efforts to identify alternative end uses for poultry manures. One such option has been the production of pelletized poultry litter (PPL) as a value-added fertilizer that is exported to farms where nutrients are needed, or for other uses, such as turf. Successful use of PPL for grain production requires agri-environmental evaluation of its value as a nitrogen (N) source and potential impacts on soil P forms and solubility. Two field studies at three farms were established at Middletown, DE to compare PPL and commercial N fertilizer (urea) as nutrient sources for corn (Zea mays L.) production under conventional and no-tillage systems, evaluate the effects of irrigation on N availability from PPL, and assess the most effective application strategy for PPL (all PPL broadcast preplant vs. a combination of PPL applied preplant and sidedressing with N fertilizer). These studies also employ cover crop plantings to determine the residual N value of PPL. Results of these field studies indicate that PPL can be an effective nutrient source for corn production and can be managed in a manner that will minimize nitrate leaching and prevent P accumulation in soils to levels that have negative impacts on water quality.