Significance of Sewage Sludge Amendments to Borrow Pit Reclamation With Sweetgum and Fescue
Sweetgum (Liquidambar styraciflua L.) and fescue (Festuca arundinocea Schreb.) were planted after subsolling and sludge applications to depths of 0, 0. 64, 1.27, and 2.54 em to reclaim a borrow pit In the Lower Piedmont of South Carolina. Sludge treatments in combination with subsoiling significantly improved establishment of fescue and growth of sweetgum, but all combinations of fescue with sludge significantly reduced first-year survival of sweetgum. Because survival was stabilized after the first growing season, allelopathy of fescue to sweetgum had little effect in this study . Fifth-year total height growth (0. 74 m) of sweetgum on the nonamended plots was rated not acceptable, but on plots amended at even the lowest rate of sludge, height growth (2.75 m) was acceptable. Total heights (ca 3.6 m) after 5 years on plots amended at the two highest sludge rates were equal to or greater than 5-year heights reported for sweetgum on reforestation sites . The increase in total nitrogen available on the site after 5 years exceeded the amount initially present in the sludge, which suggests either a significant atmospheric contribution or that organic matter enhanced nitrogen fixation.
This is a Research Note of the United States Department of Agriculture Forest Service, SE-329 (1985): 8 pp.