A COMPARATIVE SPATIAL STUDY OF INLAND VALLEY SOILS AND THE ADJOINING UPLAND REGION IN AKURE, NIGERIA

Abstract

Climate variability and changes in precipitation patterns in recent decades have led to growing uncertainty amongst farmers regarding the timing of cultivation and harvest. Most farmers have little or no experience in new cultivation methods and have barely enough capital for irrigation infrastructure or drought-tolerant crops. Inland valleys, offer extensive, relatively unexploited potential for agricultural production due to their higher water availability, lower soil fragility and higher fertility compared to upland Areas. Conventional and geospatial techniques provides scientifically accurate, cheaper, faster identification and assessment of inland valleys with adjoining upland regions in comparism with direct conventional methods. The Shuttle Radar Topographic Mission of South West Nigeria downloaded from the Global Land Cover Facility (GLCF) was used as the base map to produce the configuration of FUTA landscape to generate stream courses, buffered to delineate the inland valley areas. The perimeter of Federal University of Technology Akure Campus produced as a shape file was superimposed on the Shuttle Radar Topographic Mission imagery and extracted out using the spatial analyst/ extraction by mask tools in the Arc Map. The contours were generated using the spatial analyst/neighbourhood/focal statistics tools in the Arc Map from which the lowland and upland areas were delineated. The stream courses along the inland valley areas were generated with the use of full and flow tool in the spatial analyst/hydrology tools in the Arc Map. The streams were buffered at a distance of 100 meters using the analyst/proximity/Buffer tools and the buffered zones identified as the valley areas. The experimental design in the soil sampling was a split plot with the sampling areas comprising the inland valley and upland areas forming the main plot while seven locations in each of the sampling areas form the sub plots. Soil samples were taken at the upland and inland valley areas and the means of the values compared for significant differences. The soil nutrient concentration with average values of 1.02 %, 11.2 ppm, 0.25 cmol/kg, 3.77 cmol/kg, 1.66 cmol/kg and 3.32 % for nitrogen, phosphorus, potassium, calcium, magnesium and organic matter respectively indicated soil nutrient level to be of medium productivity which with the application of manure will become highly productive as Fadama soils.