Rooted Soil Shear Apparatus: A low-cost, direct shear apparatus for measuring the influence of plant roots on soil shear strength

Rooted Soil Shear Apparatus (RSSA) is an open-source laboratory apparatus designed to quantify the effect of plant roots on soil shear strength. Traditional methods used to assess the effect of vegetation on soil strength often rely on expensive proprietary systems and can involve sample disturbance, which may alter the root-soil interactions. This novel apparatus offers both an Arduino-based and a Raspberry Pi solution for data acquisition and control. The device enables laboratory shear testing directly in the same polyvinyl chloride (PVC) pots where the plants grow, eliminating the need to disturb the root-soil structure. Validation experiments demonstrate its effectiveness in capturing shear strength variations in rooted and non-rooted soil samples. By providing an affordable and customizable alternative to conventional shear testing equipment, the RSSA device advances research in geotechnical engineering and soil stabilization.