EFFECT OF FOREST PLANTATIONS ON SELECTED SOIL PROPERTIES AT SAO HILL FOREST PLANTATIONS, IRINGA, TANZANIA

Abstract

Some soil chemical and physical properties in plantations of Pinus patula and  were compared with those of adjacent natural Brachystegia miombo woodlands at Sao Hill. Soil moisture content and bulk density were not significantly different between plantations and natural vegetation at all sampling depths except within 0-5 cm soil depth under young pines where moisture content decreased and bulk density increased significantly. Available P did not change significantly between pine plantation and adjacent miombo vegetation but increased significantly at 0-5 and 5-10 cm soil depths under old eucalypts. Nitrate-N decreased at 0-5 and 5-10 cm soil depth under young pines, and at 0-5 and 5-10 cm under young eucalypts. Ammonium-N increased significantly at 0-5 and 5-10 cm soil depths under old pine. The implications of these changes and their relevance to future plantation productivity are discussed.