Land suitability evaluation for arable and tree crop in Kulani, Balanga Local Government Area of Gombe State, Nigeria

Abstract

Land suitability evaluation is a critical tool for achieving sustainable agriculture and meeting global food security targets. This study assesses the suitability of Kulani soils of Balanga Local Government Area, Gombe State, Nigeria, for both arable crops (maize, rice, sorghum, cassava) and tree crops (citrus, mango). Kulani’s steep slopes and limited arable land, combined with an annual population growth of 2.8% over the past decade, intensify pressure on finite agricultural resources. A survey of four plots (UP1, UP2 in upland and WT1, WT2 in wetland), from which twelve composite soil samples were collected and analyzed for physical and chemical properties. Qualitative and quantitative land evaluation methods classified land qualities: climate, soil physical and chemical properties, wetness, nutrient availability, and salinity into suitability classes (S1–S3, N). Results showed that upland soils ranged from sandy loam to sandy clay loam, while wetland soils ranged from loamy sand to sandy loam. Soils were generally acidic with low to moderate OC and TN levels but high base saturation and ECEC values. Results indicate that soil fertility is the primary limiting factor across all plots and crops, with upland soils exhibiting strong acidity and lower organic carbon, and wetland soils showing higher nutrient contents but imperfect drainage. Under current conditions, most plots are marginally suitable (S3) to not suitable (N) for maize, rice, sorghum, citrus, and mango, while cassava demonstrates moderate suitability (S2) in three plots. Potential suitability (with amendments) improves to predominantly S2, particularly for arable crops with targeted organic amendments and fertilizer applications. Recommendations include site-specific application of organic matter, balanced NPK fertilization, pH correction (lime), conservation tillage, and water management practices. This research provides a decision-support framework to guide farmers in optimizing crop selection, enhancing productivity, and mitigating land degradation in Kulani.