Soil quality dynamics and degradation potentials as influenced by land use systems in humid tropical soil of Southeastern, Nigeria

Abstract

An assessment of the effects of land use systems on soil quality dynamics and soil degradation potentials in Umuahia, Southeastern Nigeria was done in this study. Samples of soil were taken between 0 and 15 and between 15 and 30 cm. from coconut plantation (SSP₁), palm plantation (SSP₂), pineapple orchard (SSP₃) and waste dump site (SSP₄).  The result revealed sand to be the dominant soil fraction in decreasing abundance: Waste dumpsite (WD)≥ Pineapple Orchard (PO) ≥ Coconut Plantation (CP)≥ Oil Palm Plantation (OPP), followed by silt :WD  ≥ CP≥ PO ≥ OPP and clay: OPP≥CP≥PO≥WD. Land use systems recorded serious negative effects on soil physicochemical properties, with soil pH ranging  between 3.43-7.20, waste dumpsite having neutral and others having less than 6.5-8.5 as  the critical limit. The mean values of potentially toxic elements in soils as regard land use systems: Ni, Mn, Fe, Cr, Zn, Pb and Cu were all above the critical limits rendering the soil polluted. The effects of Land-use systems on biochemical indicators of soil degradation ranged from None to slightly (1) -Very highly degraded soils (4), with organic matter (OM) as biological indicator dominating the index. The effect of land use systems on soil degradation was in decreasing trend: WD > CP >OPP> PO constituting 32.5%, 26.7%, 20.8% and 20% respectively. Integrated waste management (IWM) and smart farming techniques should be encouraged for soil quality improvement.