Effects of application of mill-generated primary sludge and boiler ash on loblolly pine survival and growthThis article is part of a larger document. View the larger document here.
Use of Kraft primary sludge and boiler ash in forest production systems holds promise as a cost-effective alternative to landfilling. From a soil quality perspective, particularly in coarse-textured sandy soils, increases in organic matter content from inputs of sludge/ash may improve soil chemical, biological, and physical properties. The objective of this study was to determine the impacts of a single application of sludge/ash at site preparation on loblolly pine (Pinus taeda L.) survival and growth. In the summer of 2002, a 2:1 sludge/ash mixture from a Kraft mill was mixed into beds during site preparation at three levels: 0, 39, and 77 tons per acre. Loblolly pine was planted in February 2004, followed by N fertilization at two levels (0 and 125 pounds per acre) in May. First-year measurements of survival (SURV), ground line diameter (GLD), total height (HT), and height to live crown (HTLC) were taken in February 2004. HT and HTLC were used to calculate vertical crown length (VCL). All sludge/ash treated plots showed greater HT and VCL than control (CTL) plots. Results showed greater HT and VCL in trees receiving 39 tons per acre with no fertilization and those receiving 77 tons per acre with fertilization. GLD was significantly greater for trees receiving 77 tons per acre with fertilization. Second year results show similar results for HT but not for VCL or GLD. VCL showed less stratification by the second year, and GLD had no significant differences. There was no difference in SURV between treatments for either year. The sludge/ash mixture showed HT growth benefit. Operational costs are somewhat prohibitive without more efficient methods of transport and application.