Department of Civil Engineering, Ambo University, Ambo, Ethiopia
Abstract
This article mainly focuses on the soil conservation practices to counteract the soil degradation and to maintain the soil nutrients and organic matter. As the study area is highly prone to the soil erosion, the comparison study was initiated for the rill treatment with the help of sweet gum balls, riprap (different sizes of stones), mulch with coconut shells, bermuda grass with polyacrylamic (PAM) and a control. Five different rills of same size including an untreated control with four different materials used for making the protective covers were experimented initially using the triangular notches of 600 by maintaining the actual discharge of 0.001379 m3 sec-1. The rills were continuously kept under the visual observations for about two years which includes two monsoon seasons for each year. The changes in the size of the rills after every 4 rainy seasons are documented. The results of the experiments showed that the erosion control capacity of various protective covers are 68.4, 57, 51.2 and 44.8 respectively with the ingredients riprap, sweet gum ball, bermuda grass with PAM and the mulch with the coconut shells.
