SOIL MOISTIRE VARIATION UNDER TEAK AND GMELINA PLANTATIONS AT MEA KHLONG WATERSHED RESEARCH STATION, CHANGWAT KANCHANABURI

Abstract

Soil moisture variation at soil depth of 0-7, 7-20, 20-40 and 40-70 cm under 15-year old teak and Gmelina plantations planted with 4 x 4 meter spacing were observed in comparison with soil moisture in shifting cultivated area and natural mixed deciduous forest. The study was carried out during May 1993 to April 1994 by using gravimatric method. Results indicated that there was no significance in soil moisture condition among four land-use types in all depths, but water content in soils beneath teak plantation was less than those in Gmelina arborea and other land-use types especially in the rainy season. During the dry period, soil moisture contents through out the soil profile (70 cm depth) in all types of land use depleted to almost the same level. Water content at the depth of 0-20 and 40-70 cm beneath teak and natural forest were however lower than those beneath the shifting cultivated and Gmelina plantation areas.