DETERMINATION OF SOIL ERODIBILITY INDICES FOR SELECTED SOILS IN SOUTHERN GUINEA SAVANNA ECOLOGICAL ZONE OF NIGERIA UNDER RAINFED AGRICULTURAL PRACTICE

Abstract

A field experiment was conducted to determine erodibility index of selected soils in Southern Guinea Savanna Ecological zone of Nigeria. In each area, samples were taken from various depths of 0 – 10 cm, 10 – 20 cm and 20 – 30 cm, respectively for analysis in order to determine their physical properties. Textural triangle was used to carry out textural classification to determine the percentage dominance of the various textural classes of soil present in the selected areas. The Bougocous hydrometer method was used to determine the particle size distribution for the samples collected at various depths. The soil moisture content for plot A ranged between 9.04 to 9.14% while that of plot B ranged between 8.21 to 8.70%, plot C ranged between 7.83 to 8.51%, plot D ranged between 7.67 to 8.73% and plot E ranged from 8.73 to 9.05%. The permeability rate became stable for plot A at 45 min while at plot B, C, D and E was at 33, 45 min and 48 minutes, respectively. The particle size analysis indicated that the soil type in plot A is mainly sandy loam. It is concluded that the study area is less vulnerable to erosion as only fine soil particles are washed off as a result of the effect of surface runoff which is indicated by the negative erodibility indices obtained for the study area.