Influence of tool angles and speed on the soil reactions of a bent leg plough in two soils

The soil reactions of bent leg ploughs, as influenced by tool angles, need to be studied in detail in order to optimise their performance under different soil and operational conditions. In a field study conducted at Kumulur, south India, three bent leg tool models, with 30°, 37.5° and 45° bend angles, were tested for their soil reactions in a Typic Ustocrept (loamy sand) and a Typic Chromustert (clay loam) soil, under different speeds of operation and rake angles. A simple and reliable instrumentation system, capable of measuring the soil reactions of the tools, was developed and used in this study. Mathematical response models were built on these soil reactions to optimise the parametric levels yielding maximum performance. It was found that the tool, while working in the Ustocrept (loamy sand) and Chromustert (clay loam) soils, should have a rake angle between 9° and 15° for minimum horizontal and lateral soil reactions, and maximum downward suction, aiding penetration.