An illustration of a sustainable agricultural land suitability assessment system with a land degradation sensitivity

The degradation of soil and water resources is the consequence of a mismatch between land suitability and land use. In this study, sustainable agricultural land suitability assessment (SALSA) for wheat and perennial horticultural crops was carried out, considering a conservation-use balance using the factors affecting the crop yield as well as indicating the degradation of lands. The study area was located in the Besni district in the Southeastern Anatolia Region of Turkey and covered 1330 km2 of land. A total of 132 surface (0–30 cm) soil samples were collected and analyzed. Annual soil loss (RUSLE), gully erosion factor, soil properties and length of the growing period are included in the SALSA model. Fuzzy continuous classification was carried out using the Mamdani fuzzy inference system method. Fuzzy continuous classification-SALSA results for wheat using only the fuzzy soil layer showed that the ratios of moderately (S2), marginally (S3) and currently not suitable (N1) lands were 0.87, 72.2 and 26.9%, respectively. However, when the fuzzy erosion layer and fuzzy climate layer were integrated into the land suitability model, the ratios of sustainability classes for S1, S2, S3, N1 and N2 lands were 1.36, 3.8, 47.6, 18.6 and 28.6%, respectively. The results of perennial horticultural crops fuzzy soil layer indicated that 38.1% of the study area is S1, 57.8% is S2, and 4.02% is S3. However, when all three fuzzy layers were used in suitability assessment, the distributions of S1, S2, S3 and N1 classes changed to 2.72, 5.94, 48.86 and 42.48%, respectively.