DOF Research Evaluates Biosolids as Fertilizer on Loblolly Pine

Annual and cumulative diameter growth of loblolly pine growth through 7 years after application of biosolids and inorganic fertilizer

Annual and cumulative diameter growth of loblolly pine growth through 7 years after application of biosolids and inorganic fertilizer

In 2006, the Virginia Department of Forestry initiated a study on the use of biosolids in forest stands, an form of application that has seen a steady increase in interest from Virginia’s tree farmers.  The plots were installed in Essex County.  The design included four treatments: (1) no fertilizer; (2) urea + diammonium phosphate (DAP) at a rate of 200 lbs. of nitrogen plus 25 lbs. of phosphorous per acre; (3) lime stabilized biosolids from Arlington, applied at 200 lbs. per acre of plant available nitrogen (PAN); and, (4) the same biosolids at 400 lbs. per acre of PAN.  The treatments were applied when the stand was in its 21st growing season.

The study continues to show that nutrient additions as either biosolids or traditional inorganic fertilizer are beneficial to tree growth for at least seven years following application, and there is no evidence of any negative effects of the biosolids on loblolly pine growth.

The full research report can be found here:

http://dof.virginia.gov/infopubs/_research-reports/RR-127.pdf

Reference: Seven-Year Evaluation of Biosolids as Fertilizer in Mid-Rotation Loblolly Pine, Research Report #127, Virginia Department of Forestry