Evaluation of Land Suitability and Productivity of Rice Fields at Gunung Sewu Karst (Case Study: Ponjong and Semanu Sub-district, Gunungkidul Regency)

摘要

Rice is a staple food for most Indonesians. Rice production is very dependent on the potential of rice fields. The productive potential of each land will be different due to differences in physical and human factors. Ponjong and Semanu Subdistrict in Gunungkidul Regency were the locations of the study because these subdistricts located in the Gunung Sewu Karst Region have the widest areas of rice fields. The Karst region has unique hydrology and landforms. The purpose of this study was to describe the spatial pattern of suitability and productivity of the rice fields, as well as the relationship between the land suitability class and the productivity of the rice fields in Ponjong and Semanu Subdistrict. Variables used are surface temperature, number of wet months, drainage, texture, pH, soil depth, cation capacity, base saturation and slope, the productivity of the rice fields. The correlation matrix method is used to process land productivity data and its management, while a spatial analysis was used for the land suitability class and land productivity. The results show that the most suitable rice fields are on the western side, which is moderately suitable with nutrient retention inhibitors in a rather alkaline pH level. The lowest rice field suitability is found in the north to the south side with erosion hazard inhibitors and a slope above 15%. The study confirms the relationship between land use classes with the productivity of rice fields; more inhibiting factors found in the area, the lower the level of productivity.