Swine Manure Encasement and Phytoremediation as an Alternative Method of Lagoon Closure.

Surface water eutrophication is accelerated by non-point source phosphorus (P) pollution from high P soils or directly from P rich manures, fertilizers, or biosolids applied to soils or animal wastes stored among concentrated animal feeding operations.  Therefore, the closure of animal production facilities results in the need to safely dispose of excessive manure stored in lagoons.  Soil test P levels may limit additional land application of the lagoon sludge to surface soils upon lagoon closure and monetary costs may prohibit removal and transport of sludge to suitable application sites.  This study seeks to explore swine lagoon closure through in-situ encasement of manure and subsequent phytoremediation.  The objectives are to 1) characterize and compare sludge from a 50 and 20 yr old lagoon; 2) evaluate the use of short rotation woody species and cover crops as potential candidates for P phytoremediation based on sludge layer root penetration, P uptake and allocation; and 3) evaluate the potential for carbon sequestration of encased sludge layer compared to traditional surface sludge applications.  The results of this research will provide some insight into the potential benefits and effectiveness of the cost-saving alternative method of lagoon closure by encasement/phytoremediation.