Effects of Soil Erosion on Agricultural Productivity in Semi-Arid Regions : The Case of Lower Chambal Valley

Soil erosion is a world-wide challenge for sustainability of agriculture especially in the tropical region. The rates of soil erosion that exceed the generation of new topsoil are a dynamic process which leads to decline in the soil productivity, low agricultural yield and income. The balance between soil-forming and depleting processes is of utmost importance for attaining long-term sustainability in any production system. Land degradation in the form of soil erosion is a major problem in the semi-arid region of Lower Chambal Valley. In the present study Landsat satellite images for the years of 1977, 1990 and 2000 have been used to identify the change in degraded land in the region. Evidences suggest that the rate of encroachment of arable land is high and is equal to spreading rate of degraded land. The data obtained by field survey reveal that productivity of crop land is negatively correlated with share of degraded land to gross cropped area. The productivity of agriculture, measured through gross value of output per area, is comparatively high in villages having fewer shares of degraded land and vice-versa. Simple linear regression model explains high variation of productivity by high share of degraded land (above 50 per cent of gross cropped area). This paper provides evidences of the severity of land degradation and its close association with agricultural production of the region.