Biosolids from two municipal wastewater treatment plants were applied at different rates and times, to a thinned loblloly pine plantation to determine changes in soil nitrogen availability and tree growth response. The study was initiated in September 2005 in the Piedmont of Virginia. The study was established as a random complete block design with nine treatments of different types and rates of biosolid (lime stabilized, anaerobic digested, and pelletized). A conventional fertilizer treatment using urea plus diammonium phosphate was also included. Biosolids were applied at two different seasons (fall and winter). Soils samples were collected at four different depths (0 to 20, 20 to 40, 40 to 60, and 60 to 80 cm.) two years after biosolids applications. Inorganic and organic N was measured in the soil samples. Ion exchange membrane were used to measure NO3-N, and NH4-N in the A horizon soil. Soil solution samples have been collected monthly at 1 m in tension lysimeters and analyzed for NO3-N, and NH4-N. Foliage samples were collected one year after biosolids application. Biosolids application increased nitrogen availability in the soil. Foliar nitrogen concentrations also increased. The highest biosolids application rates increase nitrogen leaching.