Assessment of some Micronutrients, Copper, Iron and Zinc (Cu, Fe, Zn) in Soils Formed from Coastal Plain Sand, Akwa Ibom State, Nigeria

Abstract

This study was conducted to examine the levels of available copper (Cu), Iron (Fe) and Zinc (Zn) in some soils formed from Coastal Plain Sand in Akwa Ibom State. Sixteen (16) composite soil samples 0-20 cm and 20-40 cm depth were collected in eight (8) different locations and used for the study. The physicochemical properties of the soils were determined in the laboratory using standard methods while the available forms of the micronutrients were determined by the ethylene- diamine-tetra- acetic acid (EDTA) extraction method. The results show that, the soils were loamy sand and highly acidic (pH 3.6 – 5.8) with low exchangeable potassium (K) (0.02 – 0.19 cmol/kg), low to moderate total nitrogen (TN) (0.06 – 0.17 %), effective cation exchange capacity (ECEC) (6.85 – 16.98 cmol/kg) and low to high contents of organic matter (OC) (1.98 – 7.19 %). The order of abundance of exchangeable cations were Ca > Mg > K > Na. All the soils were high in available Fe (7.08 – 12. 09 mg/kg) and Zn (91.05 – 3.61 mg/kg), but low in Cu (0.06 – 0.76mg/kg). Correlation analysis showed that the micronutrients in the soils were influenced by soil pH, silt, clay and organic matter. The significant correlation among the micronutrients indicates that, their abundance and release to plant is controlled by these soil properties.  So, it is recommended that, regular soil test be carried out to monitor the levels of these micronutrients for proper fertility management of the soils to increase crop production.