The changes in land use and agricultural systems of Karen people in North Thailand: A case study of Sam Sop Bon village

Recently, the conditions prevailing in mountainous areas in mainland Southeast Asia have undergone drastic changes. In order to determine how local people adapted themselves to the new conditions, the changes in land use and agricultural systems in the survey village, Sam Sop Bon, in the mountainous area of North Thailand, were analyzed based on land use maps and interviews of the villagers. In the survey village, upland rice production based on shifting cultivation with a long fallow period had been carried out until the middle of the 20th century. In the 1960s, the fallow lands were replaced with poppy fields mainly by lowlanders, resulting in the shortening of fallow period. In the later 1970s, the whole village area became a part of a National Park, and although the confiscation and reforestation of opium fields increased the forest area, it accelerated the shortening of the fallow period and exacerbated land shortage for cultivation. Shifting cultivation disappeared and slope lands formerly used for shifting cultivation were converted to permanent cultivation fields or to reforested areas. On the other hand, technologies to produce paddy rice, whose productivity is more stable than that of upland rice produced by shifting cultivation, were introduced, and the paddy field areas gradually increased. Presently, the villagers cultivate both rice for subsistence and cash crops. Due to the reduction of upland rice productivity caused by continuous cropping, the villagers have started to use fertilizers, which in turn induced the use of herbicides because of the increase of weed problems. The present study revealed that people in the survey village intensified subsistence crop cultivation by introducing cash crops, namely diversifying agricultural activities, in response to the new conditions.