Total And Extractable Micronutrients In Soils Of Contrasting Parent Materials In Southeastern, Nigeria

ABSTRACT

Investigations into the status of total and extractable micronutrients in soils of contrasting parent materials from southeastern Nigeria, were conducted to determine the Total and Extractable forms of Fe, Mn, Zn and Cu; assess the effectiveness of cfcrent extractants for available micronutrients; evaluate the relationships between the extractable forms of the micronutrients and soil properties, and among niconutrients, and; to suggest recommcdations based on the results of this study. Twcnty surface (0-15 cm) soils developed on Coastal Plain Sand, Sandstone, Basement Complex and Shale Parent materials were used for this study. The total contents were determined by means of double acid digestion in Teflon crucible, heated on a hot plate, while the extractable contents were extracted using Cocacola, EDTA, NH4OAc +EDTA, 1 N NH4OAc and O.1N HCI extractarits. Results of this study showed that parent material influenced the concentrations of total iron, manganese, zinc and copper in the soils. The contents of total iron, ranged from 1181.40 mg kg' (Basement Complex) to 1430.10 mg kg1 (Shale); total manganese ranged from 353.60 mg kg' (Basement Complex) to 591.70 mg kg' (Coastal Plain Sand); total Zn ranged from 389.70 mg kg' (Basement Complex) to 591.70 mg kg' (Coastal Plain Sand), while total Cu ranged between 1461.30 mg kg 1 (Basement Complex) and 1787.70 mg kg 1 (Shale). Concentrations of extractable Fe, Mn, Zn and Cu varied significantly (