Changes in soil fertility following prescribed burning on Coastal Plain pine sites

Abstract

Soil and forest floor samples were collected from four prescribed burning studies in the Atlantic and Gulf Coastal Plains. The surface textures of soils ranged from sands to silt loams and the drainage classes from well to poorly drained. Burning treatments had been in force from 8 to 65 years. Reduction of the forest floor and its chemical constituents was related to frequency of burning; however, a protective organic horizon remained on all soils. Burning was found to have had no deleterious effect on organic matter or nitrogen in surface mineral soil. A comparison of earlier results with present findings suggests that annual winter burning may increase nitrogen in surface mineral soil while annual summer burning appears to reduce the total nitrogen content. Prescribed burning consistently increased the amount of available phosphorus. Fractionation of soil phosphorus indicated that burning resulted in the deposition of no specific form of phosphorus but accelerated the mineralization and cycling of the nutrient. Without burning, 50 to 60 percent more calcium accumulated in the forest floor and a correspondingly lower amount in the surface 10 to 16 cm of mineral soil. It is postulated that without burning, immobilization of calcium in the forest floor can lead to nutrient imbalance and accelerated soil weathering over a long period.

Citation

Jr. McKee, William H. 1982. Changes in soil fertility following prescribed burning on Coastal Plain pine sites. Research Paper-RE-234. Southern Forest Experiment Station Asheville, North Carolina. 23 p.