Selected Fertility Indices of Topsoil Impacted By Early Stage Erosion in Four Local Government Areas of Abia State Nigeria

Abstract

The study evaluated the effect of rill erosion on soil fertility in Isuikwuato, Ohafia, Ukwa East and Ikwuano LGAs in Abia state, Nigeria. In each location, five composite topsoil samples of 0 – 20 cm depth were collected from sites which exhibited surface erosion and compared with non eroded soils of the same location. Soil fertility indices were significantly reduced in eroded soils, with mean values of organic carbon at 3.3% in non eroded  areas, and only 1.9% in eroded soils. Nitrogen was also significantly lower in eroded soils (0.06% mean) than in non eroded soils (0.07%). Sodium Adsorption Ratio was significantly higher in eroded soils than non- eroded sites across all four locations (8.36 and 6.17 respectively), although salt concentrations were below salinity levels. There was no significant differences in pH, P, K, Ca, exchangeable acidity and effective cation exchange capacity (ECEC) due to rill erosion, even though the values were lower in eroded soils.