Effects of Land Use and Sustainable Land Management Practices on Soil Loss, Slope Stabilization and Crop Productivity

To assess the effects of different agronomic practices and SLM on soil loss and slope stabilization, a study was conducted from 2011 to 2018 at Agriculture Research and Development Center, Wengkhar, Mongar, Bhutan. The site is located at 1750 meters above sea level (masl) between 27o 3011 N and 89o 5242E. The trial was established in Randomized Complete Block Design (RCBD) with two replications and five treatments namely i. Reference plot (kept bare throughout the year) ii. Traditional practice with local cropping method iii. Traditional practice with 2 hedgerows iv. Improved practice with legume inter-cropping along with 2 hedgerows and v. Natural vegetation. The study found significant effect (p less than 0.05) of treatments on soil loss and slope stabilization. The maximum annual soil loss was recorded in Treatment 1 (2.69 t-1ha-1yr-1) followed by Treatment-2 (2.44 t-1ha-1yr-1). Though cropping area of Treatment 3 and 4 had reduced by 25 %, maximum per hectare net returns were recorded in Treatment 4 (90050.00) followed by Treatment 2 (58500.00). After 8 years the gradient of site with hedgerow plantation was stabilized by about 50 % with risers of 0.6 meters (m). To conclude, trying standard cultivation practice with legume intercrop in maize and planting grass hedgerow has significant benefit interms of controlling soil erosion, crop productivity and slope stabilization. Furthermore such studies should be continued in different agro ecological zones to gather precise and representative data.