Abstract

A field study of the status and distribution of available soil micronutrients along a hillslope of Ekpri Ibami was carried out on a 50 ha land. The aim of the study is to evaluate the micronutrient status and distribution and their relationship with some selected soil properties. A total of 16 soil samples were collected from each pedogenic horizons of four profile pits dug along a hillslope classified as upper slope, middle slope, lower slope and valley bottom. The micronutrients determined in the laboratory were iron (Fe), copper (Cu), zinc (Zn) and manganese (Mn) while the soil properties determined were particle size distribution (sand, silt, and clay), pH and organic carbon. The result obtained showed that the soils of Ekpri Ibami are characterized by sandy loam texture with sand= 706.9 g/kg, silt = 93.6 g/kg and clay = 199.5 g/kg. Soil reaction showed that the soils are strongly acidic (5.1) with low organic content (0.73 g/kg). The result of the soil micronutrients indicates that Fe content was high (5 mg/kg) in all the slope positions; copper was rated medium (0.2-2.0 mg/kg); zinc was rated low (0.8 mg/kg) at upper slope and lower slope while the middle slope and valley bottom were rated medium (0.81-2.0 mg/kg); manganese was rated medium (1.1-5.0 mg/kg) in all the slope positions. The results indicate that the sand particles, pH, and organic are the main soil properties which influences availability of micronutrients in the soil due to their significant relationships. The significant correlation among the studied available micronutrients points to the fact that, their abundance and release to plant is controlled by similar factors. The soils will not require supplementary application of Fe rich fertilizer since they are above critical limits of arable production but a complementary supply of copper, zinc, and manganese fertilizers are strongly recommended to enhancing the soil fertility status of the area.

Key words: Micronutrients, hillslope, soil productivity, food production, sustainability.