GIS-AHP based approach in land evaluation and suitability assessment for sunflower ( Helianthus annus ) production

This study aimed to analyze the appropriateness of land in Tungi Farm based in Morogoro District, Tanzania for sunflower production using a Geographic Information System (GIS). To determine appropriate areas for sunflower production, three criteria: soil properties (pH, organic carbon, total nitrogen, cation exchange capacity, available phosphorus, potassium, and soil texture), topography (slope and altitude), and climate (temperature and rainfall) were selected from the literature and employed in suitability analysis. The Analytic Hierarchy Process (AHP) method of the Multi-Criteria Evaluation was used to assign a weight to each criterion as per Saaty's Table. Cumulative weights for each criterion were used in coming up with output maps using ArcGIS 10.8. Each criterion was reclassified and assigned a weighted value. Organic carbon, total nitrogen, cation exchange capacity, and potassium were found to be adequate. Topography and climate were suitable for the sunflower production. The results from land suitability gave S1 (vastly suitable), S2 (relatively suitable), and S3 (minimally suitable) of about 51% (1022 ha), 34% (671 ha), and 15% (307 ha), respectively. The suitability map in this study could be vital and helpful in management decision options. However, the criteria considered for land suitability evaluation were mainly based on the biophysical environment, and, hence, further studies can be carried out by integrating socioeconomic parameters to improve the suitability results of the study area.