Soil Fertility Management Strategies for Sustainable Crop Production at Ifite Ogwari, Southeastern Nigeria

Sustainable agricultural production in southeastern Nigeria is hindered by declining soil fertility, where continuous cultivation and poor management have intensified nutrient depletion. This study evaluated soil fertility under arable, pasture, and forest land uses at the Ifite Ogwari Campus of Nnamdi Azikiwe University (06°60′14″N, 06°95′02″E) to identify key constraints and propose management options. A transect method was employed, and three representative soil profiles were dug across the land uses, from which twelve samples were collected along genetic horizons and analyzed for physical and chemical properties. Results revealed that soils were predominantly sandy loam (SL) to loam (L) in arable and pasture lands, and sandy loam (SL) to loamy sand (LS) in forest land use. Bulk density (1.30-1.55 Mg m⁻³) and porosity (41.5-50.9%) suggested favorable structure, but wide spatial variability was recorded for organic carbon (OC), total nitrogen (TN), and clay (CV >30%). The soils were strongly acidic (pH 4.9-5.6), with low organic carbon (<4.5 g kg⁻¹), total nitrogen (<0.4%), and critically deficient available phosphorus (<3 mg kg⁻¹). Exchangeable Ca²⁺ and Mg²⁺ were also below critical levels. Correlation heatmaps showed strong positive associations between OC and TN (r ≈ 0.99) and between Ca2+ and total exchangeable bases (r ≈ 0.98), with BD and TP inversely related (r ≈ –0.99). These findings identify soil acidity, organic matter decline, and phosphorus deficiency as the dominant fertility constraints. Recommended strategies include integrated use of organic amendments, liming, and phosphorus fertilization to restore soil productivity and support sustainable intensification in southeastern Nigeria.