Agro-forestry System in Salt Affected Area in Khon Kaen Province, Northeast of Thailand

Abstract

One of the severe environmental problems facing in the northeast of Thailand is salt affected soil. In the total area of the northeast region at 16.928 million hectare, 2.848 million hectare is salt affected land, in which the Mahasarakham rock salt layer laid at the depth of 100-200 meters. The salt affected soil is causing various economic and social problems in the rural areas. As the salt affected soil was not so serious during 1940’s when the land was covered with forests, attention has been paid to an agro-forestry system, which is one of alternative agriculture combining with forests. It is expected to reduce the intensity of salinity in the area. However, planting trees does not provide short term benefits comparing to growing field crops, so agro-forestry is hardly to be accepted by local people. Thus, the integration of salt tolerant trees and other crops could be the most beneficial for farmers and soil environment. Accordingly, this study was focused on identifying what effective agro-forestry systems are in salt affected area. Existing agro-forestry practices in Khon Kaen Province were investigated in this study. The agro-forestry practices were conducted in patch forests, paddy bunds, plantations associated with animal husbandry, home gardens and vegetable gardens. The dominant trees in these locations were Sindora siamensis, Shorea obtusa, Eucalyptus camaldulensis, Bambusa bambos and Mangifera indica. Also, the numbers of variety of trees planted in the salt affected areas were lower than that in the non salt affected areas. Based on the investigated results, it was proposed that agro-forestry practices with higher varieties of trees should be made in salt affected area.