Characteristics of Soils Along a Toposequence in Ishiagu, Eastern Nigeria and Its Relation to Potential Agricultural Landuse.

The soil along a toposequence in Isiagu, Eastern Nigeria was studied to establish its influence on soil properties and its relation to potential agricultural use. In order to characterize and classify the soil, three pedons were dug along the toposequence at the crest, middle slope and valley bottom. The soils were characterized in terms of their morphological, physical and chemical properties. The soils were generally medium to coarse textured. The distribution of clay content increased with soil depth for all pedons. The soils were strongly to moderately acid (pH 4.4 to 5.6). The highest concentration of organic carbon and organic matter occurred at the valley bottom and decreased with depth in all the pedons studied. Base saturation was low at the crest and middle slope and medium at the valley bottom. At the sub group level the soils at the crest were classified as Typic Hapludults (USDA) which correlated as Haplic Acrisols (FAO/UNESCO). The soils at the middle slope were classified as Typic Plinthudults (USDA) and Plinthic Acrisols (FAO/UNESCO). The valley bottom soils were classified as Histic Humaquepts (USDA) and Histic Cambisols (FAO/UNESCO). The soils at the middle slope and valley bottom were preferred for economic arable crop cultivation whereas the soils at the crest were most suited for forestry and wildlife. Strict measures to prevent soil erosion and replenish lost nutrients are required for enhanced productivity of these soils.