This report summarizes five years of experimentation where biosolids are immediately covered with overburden, eliminating odor problems and maintaining the biosolids in a fairly stable, anaerobic environment. The site is then planted with hybrid poplar trees, the roots of which provide a natural recycling system that utilizes the nutrients over a six-year period in most cases. An initial three year research project on the ERCO site established a 3-acre research area that was followed by another three year research project to continue monitoring of the experimental treatments.