SOIL TECHNOLOGY Soil Technology 11 (1997) 291-299 A rainfall simulation study of soil erosion on rangeland in Swaziland R.P.C. Morgan *, K. McIntyre, A.W. Vickers, J.N. Quinton, R.J. Rickson School of Agriculture Food and Enuironment, Cranfield Uniuersity, Silsoe Campus, Bedford MK45 4DT, UK Abstract Rainfall simulation studies on rangeland in the Ntondozi area of Swaziland showed that soil loss decreased exponentially with increasing vegetation cover. Vegetation exerted an important hydrological control by increasing the infiltration capacity of the soil which, in turn, influenced the time to and duration of runoff. The expected effects of vegetation on soil protection and soil strength were not demonstrated. Instead, the amount of soil loss occurring in an individual storm appeared to depend on the supply of loose material on the surface which could be transported by the runoff. 0 1997 Elsevier Science B.V. Keywords: Soil erosion; Rangeland; Rainfall simulation 1. Introduction With the growth in population and increasing livestock numbers, grazing intensity in the Middleveld of Swaziland now averages 1 Livestock Unit (LU) for every 1.3 ha and, in places, has reached 1 LU per 1.0 ha (Milner and Douglas, 19891, compared with a sustainable stocking rate estimated at 1 LU for every 2.5 (Dlamini and Maro, 1988) to 3.5 ha (Hall, 1952, cited in Nsibandze, 1987). Considerable erosion can be seen on the rangeland, particularly along paths connecting the kraals to watering points and day-time grazing areas. Cattle trails are often the focal points for severe gully erosion which is considered to be the main process of soil erosion in the country (WMS Associates, 1990) and the main problem threatening sustained agricultural production in the country (Mushala, 1988). * Corresponding author. 00933-3630/97/$17.00 0 1997 Elsevier Science B.V. All rights reserved. PII SO933-3630(97)00013-5