Deep Rows Incorporation of Biosolids to Grow Hybrid Poplar Trees on Sand and Gravel Mine Spoils in Southern Maryland

Abstract

Using deep row biosolids application to grow hybrid poplar trees (Populus spp.) on sand and gravel mine spoils is a unique and innovative beneficial-use technique that solves many of the conventional problems. The technique was developed on 50 ha (125 ac) site in the Washington, D.C. metro area by a private company (ERCO, Inc.). Research has been carried out since 2001 to develop a better understanding of water quality impacts, operational methods, clonal selection, hybrid poplar growth and nutrition, and the factors affecting economics and profitability. There are no indications of nitrate leaching and the tree plantation systems are performing well. Given the large acreage of mine spoils in the metro area, deep row application has the potential to utilize significant amounts of biosolids produced in the region.