The Effect of aspect ratio (d/w) of narrow tillage tools on draft, soil disturbed area and soil loosening efficiency

Narrow tines are among the most important tillage tools, which are used in chisel plows, cultivators and subsoilers. The draft of these blades is highly dependent on their geometric shape and working depth. The most important geometric specifications of these blades are their aspect ratio (depth/width ratio) and rake angle. Researchers’ efforts have been aimed at minimizing energy consumption and maximizing soil-loosening efficiency in using these types of blades. The objective of conducting this research was to investigate the effect of narrow tine aspect ratio on draft force; soil disturbed area and loosening efficiency. The tests were conducted in the soil-bin facilities of the Agricultural Machinery Department at Shiraz University. The experiment was conducted using a complete randomized block design with factorial arrangement in three replications. The tools had the same rake angle (30 degree) with four aspect ratios (2, 3, 4 and 5) and three blade widths (2.5, 5 and 7.5 cm). Draft force was measured by a recording load cell, and the soil-disturbed area was measured by using a profilemeter and developed by using Curve Expert and Matlab Ver. 5.6 softwares. The soil loosening efficiency was calculated by dividing the soil disturbed area by the draft force. The results showed that the effect of aspect ratio (d/w) on draft force was highly significant (p)