SOIL AND WATER LOSSES ON PLOTS WITH DIFFERENT LAND USE IN THE PHU WIANG WASPOTOMENETS WATERSHED

Abstract

The runoff and soil loss were collected from the third year at the experimental plots by the Integrated Development of the Phu Wiang Watershed Project in 1990 on 8-10% slope in the forest reserve of the Phu Wiang Watershed. Forty-five 4×20 meter plots were constructed to test three replicate of 15 different land use treatments. The treatments fall into four categories, forest plantation, cash crop, cash crop with forest plantation (agroferestry) and control (grass land.) The forest plantation included four treatments of two tree species and spacings (Eucalyptus camaldulensis and Leucaena leucocephala and 4x4 and 2x8 meters). Cash crops included two treatments, cassava and peanuts. Agroforestry included eight treatments representing the two cash crops cambined with the two different tree species and spacings. The means of soil and water losses in the forest plantation, cash crops, agroforestry and control were 0.2, 9.6, 5.9 and 0.4 ton/ha and 39.5, 328.9, 293.2 and 55.1 mm., respectively. The soil and water losses showed statistically significant different.