Assessment and Classification of Soil Fertility in Nekede, Imo State, Using the Fertility Capability Classification (FCC) System

Abstract

The declining productivity of agricultural soils in Nekede, Imo State, necessitates a functional assessment of their fertility status for sustainable crop production. This study evaluated and classified the fertility capability of soils in the Nekede area using the Fertility Capability Classification (FCC) system. Soil samples were collected from five distinct locations at two depths (0–20 cm and 20–40 cm) using a stratified systematic sampling design. Samples were analyzed for key physical and chemical properties following standard laboratory procedures. Results indicated that soils are predominantly sandy loam with high sand content (>75%) across both depths. Chemically, soils were strongly acidic, with mean topsoil pH of 5.1 and subsoil pH of 4.9. Low inherent fertility was observed, characterized by low organic carbon (1.2% in topsoil), deficient available phosphorus (9.5 mg/kg), low exchangeable potassium (0.15 cmol/kg), and a very low cation exchange capacity (<6.1 cmol/kg). Analysis of variance (ANOVA) revealed statistically significant differences (p < 0.05) between topsoil and subsoil for all major properties, including increased clay content with depth. Based on these properties, soils were classified under the FCC system as SBe⁺-ac-nk, indicating sandy topsoil with low CEC, a subsoil with higher clay content, aluminum toxicity, and deficiencies in nitrogen and potassium. Recommendations include the application of organic manure to ameliorate acidity, integrated use of organic and inorganic fertilizers to improve nutrient levels and retention, and adoption of conservation practices like mulching. This research provides a foundation for sustainable soil fertility management in the region.