Paper Title
Draught of Model Chisels Furrowers As Affected By The Interaction of Design and Operating Parameters in A Vertisol

Abstract
The influence of draught on the performance of 36 geometrically similar model chisel furrowers was investigated in a laboratory soil bin. The soil used was a vertisol composed into an artificial soil. The tool design parameters used were nose angle (10, 20, 30º), slide angle (5, 10, 15, 20 º) and cutting edge height (2, 5, 10 mm). The operating parameters were tool speed (2, 5, 10, 15 cm/s) and tillage depth (2.5, 5, 7.5, 10 cm). The results showed that draught increased with increases in all the levels of the tool design and operating parameters. The interaction of tillage depth with the tool parameters had more influence on draught than tool speed. The combined effect of depth and speed on the tool parameters also showed that depth influenced the draught more than speed. The nose angle had more influence on draught than the slide angle. Since there was no optimum value of the design and operating parameters at which the draught was minimum, the choice of a tool should depend on the furrow created as presented elsewhere. Keywords- Chisel furrower, slide angle, nose angle, cutting edge height, draught