Analysis of Soil Erodibility Factor for Hydrologic Processes in Kereke Watershed, North Central Nigeria

Abstract

: Soil erodibility factor plays essential role in determining how susceptible soil is to hydrological processes such as detachment and removal by rainfall and runoff that could influence soil erosion and sediment entrainment by flooding in an area. This paper therefore determined the erodibility k-value of soil in the Kereke watershed with the purpose of assessing its susceptibility to hydrological processes. Data was collected on some soil properties such as soil texture, soil structure, soil organic matter content, soil carbon content, soil porosity, soil bulk density, soil moisture content and soil erodibility k-value. The systematic sampling procedure was used to select thirty-two settlements which served as catchment areas for data collection; from which thirty-two soil samples were collected for analysis. Tables and graph were used to present the data, and percentages were used to depict variations in the data set. Results of the study shows that the soil samples have high percent sand particles (71.6%), moderate amount of clay particles (15.7%), silt
(12.7%), organic carbon (0.6%), organic matter (1.1%), bulk density (1.4 gcm^-3 ), porosity (45.2%), moisture content (14.0%) and low soil erodibility k-value of 0.018. The soil erodibility k-value in the study area was considered to be low, and therefore the soils are moderately erodible. This probably accounts for the moderate intensity of soil erosion channels and entrained sediments by flooding observed in the study area. It is therefore recommended that soil management practices should be encouraged by farmers especially planting of cover crops, shifting cultivation and fallowing system. This will allow nutrients gain and improved bulk density to limit soil erodibility capacity and good soil management in the area.

Key words: Soil erodibility factor, hydrological processes, Kereke watershed, North Central Nigeria