Permissible soil erosion limits under different landscapes of Chhattisgarh

Permissible soil erosion is the amount of soil loss which a soil can withstand without degrading its long-term productivity. Generally, 11.2 Mg ha⁻¹ yr⁻¹ is considered as permissible erosion limit based on the assumption that this rate of erosion equals soil formation. However, the actual erosion occurring in different sites sometimes goes far beyond this assumption. Thus, considering a single value approach as critical limit for soil erosion would be misleading. Therefore, in the present study an attempt was made to quantify the soil erosion permissible limit of different landscapes of Chhatisgarh state. The state of soil was evaluated quantitatively for different soil functions to work out the state of soil. A general guideline of USDA-NRCS was followed to calculate permissible soil erosion limits using soil state (Q) and effective soil depth. The study shows that a sizable area of 691.7 km² encompassing hilly region, undulating to rolling lands and plateau region of Chhatisgarh state can withstand a soil loss of merely 5.0 Mg ha⁻¹ yr⁻¹ thus suggesting the need for suitable conservation measures and suggesting not to construe it a safer erosion level even if soil loss is less than 11.2 Mg ha⁻¹ yr⁻¹. Only 29 per cent of the landscape has an acceptable erosion limit greater than the default value (11.2 Mg ha⁻¹ yr⁻¹) which can be considered as the safer zone and may not require immediate attention. The value of acceptable erosion lower than the default value for 70.8 per cent area of the landscape suggests that conservation planning processes need to be improved for the most of the landscapes.