Soil Characteristics Interrelationship with Treated Soil Micronutrients in Nigerian Southern

We investigated the influence of soil properties on the availability or otherwise of micronutrients in agricultural soils impacted by inorganic and organic manures in the South-South Area of Nigeria. The levels of pH, organic matter (OM), cation exchange capacity (CEC), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) in the understudy soil were examined. The measured pH, OM, CEC, Cu, Fe, Mn and Zn levels revealed: 6.04±0.49, 17.68±4.78 %, 7.97±0.81 Cmolkg-1, 5.27±0.82 mgkg-1, 232.49±16.01 mgkg-1, 109.30±9.85 mgkg-1, and 8.40±1.15 mgkg-1, for pH, OM, CEC, Cu, Fe, Mn, and Zn, respectively. The values were within the acceptable limits set by national and international standards.

The study revealed variable relationships between the soil properties and micronutrients in the studied soils at p < 0.05. Soil pH exhibited a strong negative association with all the micronutrients except Zn. However, a strong positive correlation (p< 0.10) was recorded between pH and Zn. OM showed a significant positive correlation (p< 0.10) with Fe, a weak positive correlation with Zn, and a non-significant negative correlation (p< 0.10) with Cu and Mn at p < 0.10. CEC exhibited a fair positive association with Fe and Zn, and a non-significant negative correlation (p< 0.10) with Cu and Mn. The principal component analysis (PCA) identified a combination of anthropogenic and natural impact and the impact of agrochemicals applied as the major factors influencing the properties determined in the studied soils. The study concluded that soil properties have a strong influence on the availability or otherwise of micronutrients in the soil.