Geo-spatial mapping of soil fertility status of Akure South Local Government Area, Ondo state, Southwestern Nigeria

DOI: 10.22161/ijeab.113.7

Abstract:
Soil fertility assessment is important for sustainable agricultural productivity and land management, especially in rapidly urbanizing tropical regions. This study evaluated the spatial distribution of soil fertility in Akure South Local Government Area of Ondo State, Nigeria, with a view to assess the influence of land uses on fertility status of soil in the study area. Field-based analysis were conducted on soil samples of the study location, while Geographic Information Systems (GIS) and remote sensing tools were used to map the fertility of soil under the varying land uses. Soil samples at 0-15 cm depth were collected across four land use classes: Built-up, Vegetation, Bare ground, and Outcrop, and analyzed for Nitrogen (N), Phosphorus (P), Potassium (K), Organic Carbon (OC), Organic Matter (OM), and pH. The data were geo-referenced and processed in ArcGIS Pro using the Inverse Distance Weighting (IDW) method to produce spatial distribution maps and a composite Soil Fertility Index (SFI). Results revealed significant spatial heterogeneity in soil fertility. Vegetation areas recorded the highest nutrients, N 10.08 (±9.63 mg/kg), P 12.38 (±10.34 mg/kg), K 30.92 (±28.03 mg/kg), OC 1.27 (±0.82%), OM 2.19 (±1.41%), with pH value of 5.92 (±0.42), while built-up areas were the most depleted. The composite soil fertility index (SFI) map classified the study area into five fertility zones: Very Low (0.048-0.188), Low (0.189-0.271), Moderate (0.271-0.407), High (0.408-0.600), and Very High (0.601-0.994). The study demonstrates that GIS-based soil fertility mapping provides valuable spatial insights for precision agriculture and sustainable land management.

Keywords:
Soil Fertility Index; Geographical Information System; Organic Matter; Vegetation Area; Built-up Area; Akure.

Article Info:
Received: 08 Apr 2026; Received in revised form: 08 May 2026; Accepted: 13 May 2026; Available online: 22 May 2026

Cite this Article: