Evaluation of Soil/Material Interface Friction and Adhesion of Akure Sandy Clay Loam Soils in Southwestern Nigeria

There is the need to develop appropriate and efficient soil engaging tools and implements to optimize energy required to cultivate the land and enhance agricultural productivity and sustainability in Nigeria. Necessary design data which were hitherto scarce for Nigerian soils are therefore required to accomplish the task effectively. Laboratory investigations were carried out to evaluate angle of soil/material friction and coefficient of soil/ material friction necessary in the design of soil-engaging tools and implements. Facilities used in the investigation include soil-material friction device or sliding shear apparatus. Three types of soil investigated were sandy clay loam soils. The structural materials’ surfaces investigated were rubber (RUB), steel (SST), galvanized steel (GAS) and Teflon (TEF). Results show that the coefficient of soil/material friction increased with moisture content to a limit and thereafter decreased. For the materials tested the range was 0.13 - 0.85 in the three soil textures and can be described by polynomial equations for the purpose of prediction. Rubber had the highest coeffi cient of soil/ interface friction followed by smooth steel, galvanized steel, while Tefl on had the least in that order. Key words: Soil; Coeffi cient of friction; Materials; Soil/ tool interface; Adhesion; Models