FORMS AND DISTRIBUTIONS OF OXIDES OF IRON AND MANGANESE IN AN ARABLE SOIL

ABSTRACT

This study examined the forms of oxides of iron and manganese in Ogbaru Local Government Area Anambra State. Soil samples were collected using the soil auger from Ujadumegwu and Umudiake towns in Ogbaru Local Government Area Anambra State. The soil was analyzed for some chemical and physical properties. Some micronutrients (Fe and Mn) and their oxides were also analyzed. The results show that the predominant textural class was loamy sand, with varying proportions of sand, silt, and clay. Ujadumegwu and Umudiake had distinct material compositions, with total sand dominance in Ujadumegwu topsoil and increasing clay content in Umudiake. pH values ranged from 4.10 to 4.40 with mean value (4.24) and 4.21 to 4.48 with a mean (4.36) in Location Ujadumegwu and umudiake respectively, indicating acidity in both locations. Organic carbon content was highest in Ujadumegwu topsoil, while total nitrogen exhibited variations across soil depths. Available phosphorus content decreased down soil depths, while exchangeable cations showed soil depth-related trends. The presence of exchangeable cation decreased with depth, iron and manganese content decrease with soil depth. Iron and manganese oxide content decreased with increased soil depth, with the highest values in topsoil’s of Ogbaru Local Government Area Anambra State. In general, soil chemical properties show dominance at 0 - 30cm soil depth, oxides of Fe and Mn dominate at the topsoils 0 - 30cm while soil physical and chemical properties influenced the oxides of Fe and Mn in the soils. The result further shows that soil and clay contents of the study areas greatly influence the oxides of iron and manganese present in both locations.