Abstract: The rapid erosion of soil by wind and water has been a problem ever since land was first cultivated, onsite effect include breakdown of soil structure, loss and redistribution of soil (from and from field), and decline in organic matter and nutrient which results in reduction of cultivable depth, soil fertility and soil moisture. The net effect is a loss of productivity, which at first restricts, what can be grown and results in increased expenditure on fertilizers to maintain yield but later threatens food production and lead to land abandonment. Land degradation and soil fertility depletion are considered as the major threats to food security and natural resource conservation in SSA. Various studies on land degradation in Africa have shown that besides nutrient depletion through lack of fertilizer and nutrient management, water and wind erosion are the main causes of degradation. This continued degradation reduces the capacity to increase food production. Although, large areas of forests, wetlands, river valley bottoms and grassland savannah have been put under food crops, the food gap keeps on growing. Therefore there is need for a quick and reliable estimation of potential soil losses before land use plans are made. The research uses the modified USLE equation to estimate the potential for soil losses by rainfall and runoff in a GIS environment. The equation was divided into two parts namely the potential part B which consists of the relatively constant attributes of the soil and landform while the second part (modifying part) consists of the cover and management factor and the conservation or support practice factor. The equation is applied to the Abomey-bohicon region in Benin Republic (West Africa), which is presently characterised by soil degradation, scarcity of forest cover and low agricultural yields this further highlights the need for quick assessment of potential soil losses thereby providing decision makers and resource users with information for land use planning to check further decline of the resource base. The objective is to present a simple and quick method of assessment of water erosion making use of available information thus making decision making process easier and quicker.
Lawal Olanrewaju , Thomas Gaiser and Babatunde Nuga , 2007. Estimation of Potential Soil Losses on a Regional Scale: A Case of Abomey-Bohicon Region. Benin Republic. Agricultural Journal, 2: 1-8.