Draught Requirement During Tillage

Abstract

Models to predict draught requirement during tillage are generally based on equations to calculate forces on a retaining wall for shear failure of soil. Most of the research has been made on tines, and the most important factors which determine draught requirement are the rake angle, the working depth and the soil strength in terms of soil cohesion. Most publications show a good correlation between measured values and values predicted by models; however, most experiments are based on measurements in soil bins and do not consider the tillage outcome, e.g. the aggregate size distribution. Future research should place more emphasis on draught requirement under natural field conditions, where soil strength and structure may be very different from that of (remoulded) soil in soil bins. The energy requirement should also be defined in relation to the area of soil worked (specific draught) and, especially, the tillage outcome.