Assessment of Soil Degradation in Rice (Oryza sativa L) Fields under Intensive Cultivation in Kura, Kano State, Nigeria

Soil degradation is a major threat to the sustainability of irrigated rice production in Nigeria. This study assessed the status of soils under intensive rice cultivation in Kura LGA, Kano State, by analyzing physical, chemical, and micronutrient properties from 20 composite samples (0–20 cm depth). Soil pH, electrical conductivity, organic carbon, total nitrogen, available phosphorus, exchangeable bases, and micronutrients, were analyzed to access degradation severity, while a degradation index was applied to classify severity. Results showed that soils were moderately acidic to neutral (pH 5.9-7.1) with low organic carbon (< 1%) and nitrogen (< 0.1%), indicating nutrient depletion. Micronutrients such as Cu and Zn were below critical thresholds in several locations, while high Fe (>300 mg/kg) suggested potential imbalance. Overall, 55% of sampled fields showed moderate degradation and 15% severe degradation, mainly due to nutrient mining, poor organic matter management, and salinity risks from irrigation. The findings highlight the urgent need for integrated soil fertility management, including organic amendments, micronutrient supplementation, and conservation tillage, to sustain rice productivity in the Kano River Irrigation Project area. This study delivers the first ward-level insight into soil degradation in Kura LGA, revealing spatial variability and critical nutrient threshold that inform targeted strategies to sustain rice productivity under intensive cultivation.