Utilization of Fodder Soybeans for Phytoremediation of Poultry-Manured Soil.

Poultry and animal manure are applied to cropland as inexpensive fertilizers to improve crop growth and productivity.  Continuous application of manure increases the risk of P loss from soil to water, causing toxic algal blooms and acceleration of fresh water eutrophication.  Plant-based P remediation strategies have been suggested to reduce high P accumulation in soil. We evaluated eleven fodder soybean genotypes to explore their potential for the removal of P from poultry manure enriched soils.  Field experiments were conducted during three growing seasons at a site which had a history of heavy poultry manure applications during the last ten years. The experimental design was a randomized complete block in a split-plot arrangement with four replications. Soils with and without a history of poultry manure applications were the main plots and soybean genotypes were the subplots. Experiments were also repeated in the greenhouse using the same soils obtained from both locations. Harvesting of whole plants, excluding roots, of the genotypes, was done at the pod formation stages.  Plant samples were oven dried at 70⁰ C for three days. The dry samples were ground and analyzed for total P content. Based upon the total biomass per hectare, genotypes SE73090, Mooncake, Donegal and SE737513 removed the maximum amount of P from poultry manure amended soils. However, on unamended soils, genotypes Donegal, Derry and 091734 gave maximum extraction of P. Fodder soybean genotypes could play an important role in the extraction of P from poultry manure enriched soils which is important from the ecological point of view.