Evaluation of climate change impact on soil erosion in the integrated farming system based hilly micro-watersheds using Revised Universal Soil Loss Equation

Increased rainfall intensity under changing climate scenarios threatens the sustainability of cropland due to soil erosion in the Himalayan mountain ecosystem. This study aimed to identify the resilient integrated farming system (IFS) based land use practices in hilly micro-watersheds (HMWs) under projected climate change scenarios. The IFS based land uses considered were livestock with fodder crops (HMW1), forestry (HMW2), agroforestry (HMW3), food and fodder crops (HMW4), agri-horti-silvi-pasture (HMW5), horticulture (HMW6), and abandoned shifting cultivation (HMW7, as traditional jhum), established on the hill slope (> 32.0 to 53.0%) in Meghalaya, India. The Revised Universal Soil Loss Equation (RUSLE) was calibrated and validated satisfactorily (RMSEa: 0.3 to 1.2 t ha(-1) yr(-1); NSE: 0.6 to 0.9) using 24 years measured soil loss data for each HMWs. The model was most sensitive to soil erodibility (S = 0.9 to 1.1) followed by plant cover (S = 0.6 to 1.0) in simulating the soil loss in the hilly micro-watersheds. Simulated soil losses in different HMWs ranged from 11.5 to 32.7 t ha(-1) yr(-1) under the baseline climate (1976 to 2005). The soil loss is projected to increase in the range of 7.3 to 15.3% under different RCPs (RCP2.6 to RCP8.5). The HMW with shifting cultivated IFS were the most vulnerable to climate change, as soil loss increased by 1.7 to 8.4 t ha(-1) yr(-1) over baseline (32.7 t ha(-1) yr(-1)). However, HMW with horticulture based IFS followed by agroforestry showed the most resilience to climate change and manifested a minimal increase (0.6 to 3.1 t ha(-1)yr(-1)) over baseline soil loss (11.5 to 12.0 t ha(1) yr(-1)). Adoption of horticultural and agroforestry based IFS on the hill slope of Eastern Himalayan ecosystem is an effective measure to control soil erosion.