Geospatial assessment of micronutrient status in agricultural soils of Kura, Kano state, Nigeria

Abstract

The sustainable management of soil fertility, particularly micronutrients, is critical for enhancing crop productivity and nutritional quality in West Africa. This study employed geostatistical techniques and a Geographic Information System (GIS) to assess the status and spatial distribution of available Zinc (Zn), Copper (Cu), Manganese (Mn), and Iron (Fe), alongside soil pH, across 70 sampling points in Kura Local Government Area (LGA), Kano State, Nigeria. Descriptive statistics revealed high coefficients of variation (CV) for all micronutrients, indicating significant spatial heterogeneity and the inadequacy of uniform fertilizer application. Semivariogram analysis confirmed a strong to moderate spatial dependence for all elements, allowing for reliable spatial interpolation via Kriging. The resulting maps delineated distinct zones of deficiency, sufficiency, and potential excess for each micronutrient. While mean values suggested generally high levels of Fe, Mn, and Zn, the spatial maps highlighted localized areas where targeted management is essential to prevent both deficiency-induced yield loss and potential toxicity. The findings underscore the necessity of adopting Precision Agriculture strategies in Kura LGA, providing a critical foundation for developing site-specific nutrient management plans to optimize crop production and soil health.

Keywords: Geostatistics, kriging, precision agriculture, DTPA extraction, spatial interpolation, nutrient mapping