Phosphorous Phytoremediation of Manure-Enriched Soil Using Diverse Plant Species.

Animal manure has been used for decades to improve soil fertility and thus, increase crop productivity.  The continuous amendment of cropland with manure has resulted in excess phosphorus (P) in soils that is usually associated with undesirable effects, such as pollution of the Chesapeake Bay, eutrophication, and fish kill in water bodies. In the Delmarva Peninsula, plant-based P remediation strategies have been suggested as an environmentally-friendly process to clean the bay. Crops such as corn, sorghum, Sudan grass, soybean, and cowpea were used in this study.  Our main objective was to determine the difference in P uptake by the various genotypes of corn, soybean, and cowpea harvested at milk stage of grain formation in poultry manured enriched soils. Field experiments were conducted during three growing seasons at two sites; one site had annually received poultry manure in the last ten years while the other site had not received any manure.  Results showed that corn genotypes 57K14 and DKC 64-11 exhibited superior P uptake in both soil treatments. The superior P extraction of genotypes 57K14 and DKC 64-11 relative to that of other genotypes indicates a potential to improve P uptake by corn genotypes and the possibility of using this innovative approach for phytoremediation of soils.  Further, selected genotypes of corn, cowpea and or soybean could play a significant role in soil nutrient management. This would alleviate the concern of the movement of P from poultry manured-soils into ground water, drainage ditches; subsequently causing aquatic systems degradation.