Survey and classification of highland rice cultivation areas to indicate acid soil crisis was conducted on altitude 700 meters above sea level. Soil sampling was conducted form 7 districts of Mae Hong Son province are namely Muang, Khun Yuam, Mae La Noi, Mae Sariang, Sop Muey, Pai and Pang Ma Pha in the year 2012-2013. A total of 115 soil samples were consisting of 68 paddies and 47 upland conditions. Soil samples were analysis to find out the soil pH. The result showed that the strongly acid, moderately acid and slightly acid are 39.13, 21.74 and 20.86 percentages, respectively. In other hand, the natural, very strongly acid and extremely acid are 8.7, 7.83 and 1.7 percentages, respectively. However 39 percent of upland soil sample and 38 percent of paddy... |