1. Soil loss study under different grasses strip and grasses hedge spacing against soil erosion on the highland 2. Soil loss study under contour bunds substitution of different leucaena hedgerow density for soil and water conservation on the upland of upper northern Thailand 3. Soil loss study under different soil and water conservation measures for maize and redbean cultivation on steep land 4. Comparison of soil loss and moisture content by using different cropping patterns for soil and water conservation on steep land