Soil erosion from arable lands removes the top fertile soil layer (comprised of humus/organic matter) and therefore requires fertilizer application which affects the overall sustainability. Hence, determination of soil erosion from arable lands is crucial to planning conservation measures. A modeling approach is a suitable alternative to estimate soil loss in ungauged catchments. Soil erosion primarily depends on soil texture, structure, infiltration, topography, land uses, and other erosive forces like water and wind. By analyzing these parameters, coupled with geospatial tools, models can estimate storm wise and annual average soil losses. In this study, a hilly watershed called Nongpoh was considered with the objective of prioritizing critical erosion hazard areas within the micro-catchment based on average annual soil loss and land use and land cover and making appropriate management plans for the prioritized areas. Two soil erosion models namely Revised Universal Soil Loss Equation (RUSLE) and Modified Morgan–Morgan–Finney (MMF) models were used to estimate soil loss with the input parameters extracted from satellite information and automatic weather stations. The RUSLE and MMF models showed similar results in estimating soil loss, except the MMF model estimated 7.74% less soil loss than the RUSLE model from the watershed. The results also indicated that the study area is under severe erosion class, whereas agricultural land, open forest area, and scrubland were prioritized most erosion prone areas within the watershed. Based on prioritization, best management plans were developed at catchment scale for reducing soil loss. These findings and the methodology employed can be widely used in mountainous to hilly watersheds around the world for identifying best management practices (BMP).

Typical pedons representing major landforms of Nongpoh micro-watershed in Ri-Bhoi district of Meghalaya viz., hill top, hill slope and inter hill valley developed from granite–gneiss occurring under varying land use were characterized, classified and assessed. The soils were deep to very deep in depth, brown to greyish brown in colour, slightly acidic to extremely acidic in reaction and high to medium in organic carbon. Further, the soils were low to high in available nitrogen, low to high in available phosphorus and medium to high in available potassium. Pedon P2 and P3 which are located on the hill top and the hill slopes, respectively showed cambic (Bw) sub-surface diagnostic horizon and were classified as Typic Dystrudepts while the hill top pedon P1 and on hill slope pedon P4, sub-surface diagnostic horizon possessed argillic (Bt) horizon which was classified as Typic Paleudalfs. However, pedons located on the inter hill valley (P5 and P6) did not exhibit any diagnostic horizon and hence were classified as Oxyaquic Udifluvents and Aeric Endoaquents, respectively.

A Crop coefficient (k_c) was determined for Capsicum annumm L. (hot pepper) with the help of UMS-GmBH cylindrical field lysimeter of 30 cm diameter and 120 cm deep and Penman-Monteith FAO-56 model. Penman-Monteith model is the universally adopted standard model for estimation of reference evapo-transpiration (ET₀) based on local weather parameters. Eight other models viz. Modified Penman Method, Hargreaves equation, Samini Hargreaves equation, Thorthwaite equation, Solar Radiation Method, Net Radiation Method, Blaney-Criddle Method and Radiation Method were also used for estimation of ET₀ and compared with Penman-Monteith model to find out the accuracy of prediction with limited weather parameters. Scatter plot and paired t-test were used for comparison. Out of all these models, Blaney-Criddle Method was found to yield similar results as given by Penman-Monteith model. The values of crop evapo-transpiration (ET_c) were varying from 1.11 mm d⁻¹ to 3.12 mm d⁻¹. k_c is the ratio of ET_c to ET₀. The highest k_c value was obtained during the maximum vegetative growth in 8th week after transplantation. The crop-coefficients for three growth stages viz. initial, mid and maturity were found to be 0.33, 0.64 and 0.30, respectively.

Land use planning based on land capability classification (LCC) was done for Nongpoh watershed located in perhumid hyperthermic subtropical climate in Meghalaya. Satellite data of IRS-P6 LISS-IV of December 2011 (spatial resolution of 5.8 m) was used as base map for the study. Standard visual interpretation based on tone, texture, pattern, shape and size was used for preparation of land use/land cover map. Soil profiles were exposed in each physiographic unit, studied for morphological properties and classified. Horizon wise soil samples were collected from representative pedons and analysed for their different physical and chemical properties. Arc-GIS software was used for digitization, data interpretation and thematic map preparation. Three crops viz., rice, maize and pineapple were assessed for their suitability for growing in the watershed area. Out of 265.91 ha watershed area only 10.97% area was suitable for paddy cultivation. Maize was suggested in few low-land areas where rice cultivation had some limitations. The upland hill soils with less than 15% slope are suggested for maize and pineapple cultivation besides agroforestry. In the higher hill slope with slope of 15–45 per cent are suggested for pineapple or agro-forestry. Aforestation is suggested where land is not suitable for any kind of cultivation for better resource utilization in a sustainable way.