20. Management Strategies for Critical Erosion-Prone Areas of Small Agricultural Watershed Based on Sediment and Nutrient Yield

Identification of the critical areas is essential for the effective implementation of watershed management programs. In the present study, monitoring of runoff, sediment, and nutrient yield (NO₃–N and soluble P) was carried out from a small agricultural watershed to identify the critical areas on the basis of sediment and nutrient yield. Land use/land cover information was generated from Indian Remote Sensing Satellite data (IRS-1D-LISS-III). Universal Soil Loss Equation (USLE) was used to estimate soil loss from the study area, while remote sensing and GIS techniques were used for parameterization of USLE model. Delivery ratio was computed for the watershed to compare with the observed sediment yield. Soil samples were collected and tested from a selected portion of the wasteland for measuring soil fertility status (NPK), soil reaction (pH), organic carbon content, etc. The sediment delivery ratio in the study watershed ranges between 0.44 and 0.66. All the sub-watersheds fall within “slight” soil erosion class (0–5 ton ha⁻¹ year⁻¹). Sub-watershed I yielded more nutrient followed by Sub-watershed II and Sub-watershed III. The wastelands of the study area have a moderate amount of organic carbon (within 0.5–0.75%) and low available nutrient (NPK), initially, farmers can go for leguminous crop cultivation for increasing the nitrogen status of the field, and also, sabaigrass-based intercropping systems can be adopted in small plots of the wasteland.