The classification of suitable areas for agriculture in Sakaeo Province, Thailand

Thailand is an agricultural country, and paddy rice is the main product. The grains are used for domestic consumption and export. However, the change in agricultural areas to urban areas is a major cause of the loss of good agricultural land. The revenue of Sakaeo Province comes from agricultural products, including rice, cassava, maize, sugarcane, soybean, cotton, mung beans, fruit crops and other perennials, and for this reason, the best farmland should be protected. The objectives of this study were to study land use in Sakaeo Province and to determine a suitable class of agricultural land. This study is a response to national, provincial, and local policies on agricultural land protection. The Geographic Information System (GIS) was used as the analytical tool, and the overlay technique was used to integrate the relevant factors, including soil suitability, water availability, crop revenue, plant production technology, land reform, landholding, and existing land use. Five classes of agricultural land were proposed; namely, Agriculture Class I, II, III, IV, and V. Agriculture Class I represents the best area and is the most suitable for agriculture. In contrast, Agriculture Class V is not suitable for agriculture. The results of the classification of suitable areas for agriculture in Sakaeo Province showed that the area most suitable was Agriculture Class II (33.63%), followed by the areas of Agriculture Class I (25.16%), Agriculture Class V (32.59%), and Agriculture Class III (8.61%). Agriculture Class IV areas were not found. Twenty-five point one six percent of the Agricultural Class I land was found in different areas, including Amphoe Muang (7.36%), Wattana Nakon (6.59%), Aranya Pra Teat (2.76%), Ta Phra Ya (2.31%), Wang Sombun (1.62%), Khok Sung (1.48%), Khao Chakan (1.23%), Khlong Hat (1.04%), and Wang Nam Yen (0.77%). Thirty-three point six three percent of the Agricultural Class II areas included the following: Aranya Pra Teat (6.51%), Ta Phra Ya (5.68%), Wattana Nakon (5.10%), Khao Chakan (3.99%), Amphoe Muang (3.98%), Khlong Hat (3.06%), Khok Sung (2.81%), Wang Nam Yen (1.55%), and Wang Sombun (0.96%). Eight point six one percent of the Agricultural Class III areas included the following: Wang Sombun (3.79%), Wang Nam Yen (1.77%), Khlong Hat (1.71%), Amphoe Muang (0.43%), Khao Chakan (0.35%), Wattana Nakon (0.33%), Khok Sung (0.06%), Ta Phra Ya (0.06%), and Aranya Pra Teat (0.1%). Point four percent of the Agricultural Class IV land was found in the following different areas: Wang Sombun (0.12%), Wang Nam Yen (0.11%), Khlong Hat (0.04%), Wattana Nakon (0.04%), Khao Chakan (0.03%), Khok Sung (0.03%), Amphoe Muang (0.02%), and Aranya Pra Teat (0.01%). Agricultural Class IV land was not found in Ta Phra Ya. Thirty-two point one nine percent of the Agricultural Class V land was found in the following different areas: Wattana Nakon (9.54%), Amphoe Muang (8.64%), Ta Phra Ya (5.82%), Aranya Pra Teat (1.65%), Khlong Hat (1.31%), Khok Sung (1.32%), Wang Sombun (1.78%), Khao Chakan (1.14%), and Wang Nam Yen (0.99%). It is recommended that first, the Agricultural Class I and Class II land (58.79%) be protected from other activities. Second, this research demonstrations an alternative method for the classification of agricultural land because it uses both physical properties and socio-economic data.