Phytoremediation of Poultry Manured Soils Using Diverse Plant Species.

Poultry manure application to crop land is a widely used practice in the Delaware, Maryland and Virginia (Delmarva) region. This increases the contents of phosphorus (P) and other nutrient elements in the riparian environment causing degradation of aquatic systems and serious ecological side effects. We evaluated five cowpea, four corn, four Sudan grass and eleven soybean genotypes to explore their potential for the removal of P from soils. Field experiments were conducted during two growing seasons at the Agricultural Experimental Station, University of Maryland Eastern Shore, Princess Anne, Maryland, at two sites which had a history of heavy poultry manure applications during the last twenty-five years.  Experiments were arranged in randomized complete block designs with four replications.  Harvesting of the cowpea and soybean genotypes was done at pod formation stages while sampling of corn and Sudan grass genotypes was done when plants were in their early milk stages of development.  Plant samples were oven dried at 70º C for three days, and the dry samples were ground and analyzed for P content.  Results showed that cowpea genotypes Champion and White Acres extracted significantly higher amounts of P compared with the other cowpea genotypes. These two genotypes were also found to have a higher potential for P uptake from poultry manure enriched soil.  On the other hand, soybean genotype 091734 and SE 737513 extracted significantly higher amounts of phosphorous under field conditions, and the same general trend was also found in the greenhouse studies.  Sudan grass, however, extracted the maximum amounts of P compared with other genotypes of corn and sorghum.  This approach of using plant genotypes such as sorghum, Sudan grass, cowpea and soybean for phytoremediation can play a significant role in improving nutrient management and environmental quality, and, thus, enhance agrosustainability.