Sequential Fractionation of Phosphorus in Soils Amended by Fresh and Pelletized Poultry Litter.

Excess manure nutrients generated by the poultry industry on the Delmarva Peninsula have been identified as a major contributor to watershed-scale nutrient surpluses and thereby water quality degradation.  One innovative solution to this regional nutrient imbalance has been to transport excess poultry litter to a local pelletizing plant where it is converted into an organic fertilizer.  Widespread adoption of pelletized poultry litter (PPL) in commercial agriculture has been slow, in part due to the lack of knowledge about nutrient mineralization rates.  The forms of phosphorus (P) present in soils after pelletized and fresh poultry manure application were determined using a soil incubation experiment.  Soil samples were collected and analyzed 1, 7, 30, 60, 120 and 365 days after manure application.  Fresh and pelletized poultry manure were applied at 2 rates, 100 and 200 kg ha^-1,on a clay loam and sandy loam soil.  The soil samples and poultry manure were analyzed using a sequential extraction technique to determine P fractionation.  The results of the study will be discussed.