A comparative assessment of rain erosion hazard of five land use types and Management Practices in Mhong Chun Yen Village, Northern Thailand using Soil surface Micro-Topographic features of Erosion

A study was carried out to compare rain erosion hazard on five sites representing different land use systems and management practices on the hill farms of Mhong Chun Yen Village in Northern Thailand, by a rapid, cheap, effective but unconventional method. This method employs seven soil surface micro-topographic features of erosion by rain. The aim was to identify which of these land use types and management practices present the most resistance to land degradation in the highly erosion-prone hill farms region. The results obtained showed that the differences observed in erosion-resistance on the five sites were traceable to variability in the type and density of surface cover, surface roughness, management practices, timing of agricultural activities and slope steepness. In a decreasing order of resistance to erosion, the five different land use types/management practice combinations ranked as follows: Orchard of 5 years old longan, litchi and mango/grass cover (70% of total surface area) and surface graved (5%)/ herbicide and pesticide use > agroforestry (of teak, banana and lemon grass)/ grass cover (65%)/grazing/old terrace > arable (maize and melon)/slash and burn/tillage with hand hoe/weeding with hand hoe and later with herbicide/fertilizers use/ stubble mulching/land cultivated for the 20th year continually/contour ploughing > arable (maize and melon)/slash and burn/land cultivated for the 20th year continually/contour ploughing with a 4-wheal tractor > young orchard (1 year old longan) interplanted with ginger/mulching/fertilizer use/land cultivated to cotton for 14 years continually/ploughing with a 4-wheal tractor up-and-down slope. Invariably, the land use types and management practices that provided more cover and surface roughness exhibited greater resistance to erosion. Moreover, surface cover, wherever dense and perpetual appeared to have the potential to mask the expected hazardous effect of slope steepness on erosion hazard on the hill farms. With this information, the right extension advice could then be preferred, which if adopted by the farmers could do much to preserve the region's soil resources and improve their own livelihoods.