ABSTRACT
Agricultural productivity in the Sudan Savanna Zone of Kebbi State, northwestern Nigeria, is under considerable strain due to declining soil fertility, inadequate soil management practices, and environmental degradation. Field experiment was conducted at Birnin Kebbi Local Government Area of Kebbi State to analyze the soil productivity indices for sustainable crop production in the Sudan Savanna Zone of Kebbi State. Soil samples were collected from two soil strata. From each stratum, two composite samples were obtained; three borings were made using systematic random sampling, at the depth of 0-30 cm, 30-60cm and 60-90cm giving a total of six composite soil samples. The soil samples were analyzed in the laboratory using standard analytical techniques. Total Nitrogen (N), available Phosphorus(P), Potassium (K), pH, Moisture content (MC) and Electrical conductivity (EC) were determined and the data was analyzed using ANOVA where treatments show significant differences DMRT was used for mean separation. It was found that Soil NPK was high 30-60cm at sampling depth(1.1%, 8.0mg/kg-1, 0.6cmol/kg-1) in low land but found high at 0-30cm sampling depth (0.4% and 0.3cmol/kg-1) in upland except P which was found high (0.8mg/kg-1) in 60-90cm sampling depth. EC recorded highest mean value at 60-90cm sampling depth, while other parameters tested showed no significant differences. The research concluded that soil fertility is dynamics in Birnin Kebbi and is largely controlled by topography, drainage, and depth, underscoring the need for site-specific soil fertility management practices. Fertility management in uplands should emphasize organic matter addition and nitrogen supplementation at the surface layer to sustain crop productivity.