Assessment of soil suitability for rice cultivation potential in the coastal region of Bangladesh: A GIS-based approach for Sarankhola Upazila, Bangladesh

Rice is the staple food in Bangladesh. However, soil degradation in coastal land hinders rice production there. This study aims to assess the suitable area for rice production in Sarankhola, a coastal region in Bangladesh. This study uses SRDI’s physiochemical and nutrient data as a secondary source. We interpolated these data using Inverse Distance Weighting (IDW) methods and weighed the data using the Suitability Modeler in ArcGIS Pro v3. The findings show that some parameters, like OM, N, P, Cu, and Mn, are close to or within their optimal ranges suggested by SRDI, for rice production in Bangladesh. On the other hand, EC, S, Ca, Mg, and Fe are much higher than their optimal values. The correlation analysis shows strong positive correlations between organic matter and nitrogen (0.97); and Ca and Mg (0.64). Moreover, there is a moderate positive correlation of Soil EC with S (0.43), and K (0.34), respectively. Conversely, a negative correlation was found between soil pH with N (-0.28) and Organic Matter (-0.30), respectively. The spatial distribution of soil physiochemical and nutrients reveals varying suitability for agriculture, with some regions showing optimal conditions while others face significant nutrient deficiencies. The land suitability analysis for rice production reveals that 40–50% of the area, mainly in the Dhansagar and parts of Khontakata unions, is "suitable" for rice cultivation. Meanwhile, 20–30% of Rayenda, Southkhali, and parts of Khontakata are "moderately suitable," necessitating additional inputs. The remaining 30-40%, particularly in Rayenda and Southkhali, are "marginally suitable." The results suggest that Dhansagar and Khontakata unions in Sarankhola are potential areas for rice production naturally, without using hybrid seeds.