Authors:
Madubuike, C. N.,Nwachukwu, P. I., Emerson, K. U. and Asuzu, C. C. , Nigeria |
Abstract:
A performance evaluation of selected erodibility indices for erosion prediction of soils of Imo
State, Nigeria, was performed. Soil samples were collected from 12 locations across three
regions of Imo State (Owerri, Okigwe and Orlu), using completely randomized design. Samples
were analysed for erodibility indices: modified clay ratio (MCR), clay ratio (CR), dispersion
ratio (DR), and erosion ratio (ER), alongside selected physicochemical properties. Results
indicated that the soils are predominantly sand. Soils of Owerri region are loamy sand texture,
while Okigwe and Orlu regions are Sandy loam and Sand textured respectively. Bulk density of
soils ranged from 1.50Mg/m3 1.81Mg/m3, while soil organic matter (SOM) averages 2.27% for
Owerri and Orlu, and 0.92% for Okigwe respectively. MCR varied across the various locations
in the order of Orlu (65.23 80.01) > Okigwe (43.11 55.30) > Owerri (15.20 35.65) regions.
Least DR (0.58) and ER (0.44) were recorded in Owerri region, while highest values of 0.99 and
0.91 were recorded in Orlu region. A simulated rainfall intensity of 165mm/hr resulted in 1.2
ton/ha and 6.6 ton/ha annual soil loss for Owerri and Orlu respectively. Soils of Owerri region
were considered less susceptible to erosion because of their loamy sand textured nature and
relatively high organic matter content. All the erodibility indices showed positive correction with
soil loss. MCR was most positively (R2=0.7579) correlated, followed by ER (R2=0.7279), while
DR and CR showed slightly lower correlation with soil loss, with R2 values of 0.7056 and
0.7279 respectively |
