Simplified erosion test for soil cylinders

Different soil erosion equipments have been used to predict soil erosion but most of them are either expensive or spacious or both. There is no standard equipment for soil erosion prediction. The purpose of this study is to develop a simplified erosion equipment to test cylindrical soil and planted soil samples. The equipment provides simple setup with simple sample preparation. It generates shear stress by an agitator which is attached to a flat paddle. Shear stress can be regulated by adjusting the revolution of the paddle. Generated shear stress by other existing erosion testing devices is generally uniform along the soil surface. This erosion setup produces a vortex that generates maximum shear at the middle of the impeller which is more suitable to test plant stabilized soil samples as main root system of plants are at the middle of the cylinder. In this study tests of different soil cylinders which include soil samples (soil only), plant stabilized soil samples (Un-infused) and polymer-infused plant-stabilized soil samples (Infused) were conducted by this setup. Two types of soil, marked as Type 1 and Type 2 were used for preparation of samples. Different paddle revolution rates were tried and for each of revolution rate, the test results were analyzed in terms of the immediate erosion initiation, erosion amount, erosion rate etc. The revolution rate of 300 rpm yielded the stable erosion results was selected for this study. The validity of the proposed equipment and stability of the test results were verified by published data. Using this erosion equipment, the soil erosion of infused and un-infused plant roots stabilized cylindrical soil samples was also examined. Infused plant root stabilized soil samples are in-situ plant-polymer composite material of high tensile strength which were created by infusing polymer into the xylem vessel of the plant. By this process, a stable root nest in the soil mass was created which can work against soil erosion and requires minimum maintenance. Based on the results, 78.79% less soil erosion for un-infused samples at 16 hours erosion time at 300 rpm paddle rotational speed was observed. Soil erosion for both infused and un-infused samples were similar. In order to check the permanency of polymer infused roots, nine samples of one year old were also conducted but no significant differences were observed among the test results.