Rice Straw Geotextile As Ground Cover ForSoil Erosion Mitigation

Abstract

Generally, the study aimed to mitigate soil erosion using rice straw geotextile as ground cover. Specifically, it attempted to: evaluate the effect of RSM and RSN as ground cover in mitigating soil erosion at varying slope gradients and different rainfall intensities, and; determine the relationship of slope gradient versus sediment concentration, sediment yield and quantity of soil loss at different levels of rainfall intensity. Results revealed that RSGT as ground cover greatly affected soil erosion. Under rainfall intensities of 75, 100 and 125 mm/hr, RSM had significantly lower soil loss as compared to RSN, CCN And NGC. However, RSN and CCN were comparable with each other but differ significantly with NGC.  Sediment concentration, sediment yield and soil erosion exhibited a nonlinear relationship with slope gradient. At any given level of rainfall intensity, the three indicators increased correspondingly as the slope was increased from 10 to 35^o and then  declined when  the slope was further  increased from 35 to 60^o.

Sediment concentration best fitted (R² = 0.977) in a quadratic model in the form of a second-degree polynomial equation:

SC = 0.551 + 0.626S - 0.008S²

Likewise, observed sediment yield best fitted (R² = 0.954) a second degree polynomial equation as expressed by a quadratic model:

SY = 356.0 + 61.70S – 0.972S²

Moreover, the observed soil erosion was best modeled with R² = 97.1% confidence by a second degree polynomial equation. The regression model is quadratic in form and is given by the equation:

SE = 68.92 + 11.11S - 0.174S².

Keywords: rice straw, geotextile, ground cover, soil erosion, mitigation, rainfall simulation