SOIL AND WATER LOSSES FROM DIFFERENT LAND USES

Abstract

The runoff and soil loss were collected from the experimental plots at the Integrated Development Project, Phu Wiang Watershed, Khon Kaen Province during 1988 to 1992. The experimental plots located on 9 % slope at the forest plantation of the Phu Wiang Watershed. Forty-five 4 x 20 meter plots (three replicates) were constructed consisting of 15 different land use types. The treatments fall into four categories: forest plantation, cash crop, cash crop with forest plantation (agroforestry) and control. The forest plantation included four plots with two species and spacings (Eucalyptus camaldulensis and Leucaena leucocephala planted with 4 x 4 and 2 x 8 meters). Cash crops included two treatments cassava and peanut. Agroforestry included eight plots representing two cash crops combined with the two different tree species and spacings. The means of soil and water losses during 1988 to 1992 in the forest plantation were 1.60, 1.50, 0.20, 0.40 and 0.07 ton / ha and 115.5, 57.2, 39.5, 48.9 and 18.3 mm. respectively. In the cash crops, soil and water losses were 18.60, 21.10, 9.60, 7.00 and 4.99 ton / ha, and 363.8, 232.0, 328.9, 257 2 and 174.2 mm, respectively. In the agroforestry, soil and water losses were 18.60, 15.10, 5.90, 4.60 and 3.29 ton / ha, and 395.6, 239.7, 293.2, 238.7 and 144 8 mm, respectively: and the control were 74.20, 29.60, 0.40, 0.30 and 0.20 ton / ha and 377.7, 294.5, 55.1, 37.5 and 5.5 respectively. The soil and water losses showed statistically significant different in each year.