Soil loss on noncultivated land in the Middle Hills of Nepal

This paper reports soil losses from 15 erosion plots in the Middle Hills, Nepal, for the 1992 and 1993 monsoon and pre-monsoon seasons. In total, 912 rainfall events were monitored. Land cover varied from grassland and relatively undisturbed mixed broadleaf forest, to degraded Sal forest and bare ground. Soil losses ranged from less than 0.1 t ha(-1) yr(-1) for grassland and undisturbed forest plots, to 3-10 t ha(-1) yr(-1) for Sal forest in various states of degradation, and over 15 t ha(-1) yr(-1) for the bare sites. These results are broadly consistent with those reported in other parts of the Himalayan Middle Hills. Soil loss values could be explained by variations in runoff amounts and rainfall intensity, as well as by the nature of the land cover. Ground and low shrub cover was more important than canopy cover in protecting the forest soils. Human activity has unquestionably led to accelerated rates of soil loss but the degree of acceleration depends on the nature of the human activity and especially the care with which the land is managed.