Effect of lime stabilized biosolids and inorganic fertilizer applications on a thinned longleaf stand - ten year resultsThis article is part of a larger document. View the larger document here.
This project was initiated on the Sand Hills State Forest in Chesterfield County, SC in May 1995 to determine the benefits of inorganic fertilizer (NPK) and lime stabilized biosolids applications in a twice-thinned longleaf pine (Pinus palustris Mill.) stand planted in 1963 on an excessively well drained deep sand (Alpin soil series). Major objectives included quantifying the magnitude and duration of pine straw response, stand growth, and economics of each treatment over a ten-year period. The experimental design was randomized complete block design with three replications with treatments applied in the spring of 1995 and reapplied in the spring of 1999. Treatments were: control (no fertilizer), NPK, and lime stabilized biosolids. All living tagged trees in treatment plots were measured (d.b.h, total height) prior to the first application in March 1995 and re-measured in February-March 1997, 1999, June 2001, February 2003, and August 2005. Results indicate a significant near term pine straw production benefit to NPK and the biosolids treatments in years 2 and 3 after the first application. Mean NPK and biosolids treatment plot basal area per acre and volume per tree increments during the periods 1999-2005 and 1995-2005 were significantly greater than the control. Mean NPK plot volume per acre increment was significantly greater than the control and biosolids plots during the period of 1995-1999. The NPK and biosolids plot volume per acre increments during 1999-2005 were significantly greater than the control. Ten year total volume per acre increment was significantly greater in NPK plots than in biosolids plots and biosolids plots were significantly greater than the control.