Land suitability evaluation using selected environmental physical parameters for coffee plant productivity in Tana Toraja, South Sulawesi, Indonesia

Abstract Coffee is a prominent commodity in Indonesia, and its price fluctuations depend on quality influenced by the physical conditions of the growing environment. The study area was chosen to enhance the productivity of the Toraja coffee industry, known for its export-grade coffee. This study aims to identify and examine the characteristics of environmental physical parameters and coffee productivity to provide land improvement recommendations for low coffee productivity areas. Regression analysis was conducted to evaluate the connection between elevation, slope, and soil texture with coffee productivity. Elevation and slope data were acquired from SRTM DEM images. Soil texture data were obtained from the Ministry of Agriculture’s land system. Coffee productivity data were collected through field surveys and questionnaires using digital applications. Results indicated that elevation had varying relationships for each land suitability class (S1, S2, and S3). The coefficients of determination, 0.17, -0.51, and 0.49, respectively, showed different levels of association, with class S3 demonstrating a stronger relationship. Slope in class S2 exhibited a strong correlation with coffee productivity. Meanwhile, soil texture parameters had a limited impact, with the highest productivity occurring in class S3. In conclusion, the most influential environmental parameters on productivity, in sequence, were slope, soil texture, and elevation.