DEVELOPMENTS WITH SEED DRILL COULTERS FOR DIRECT DRILLING .1. TRASH HANDLING PROPERTIES OF COULTERS

To extend the range of surface conditions under which an experimental non-rolling direct drilling coulter could operate, several trash clearance modifications were evaluated. The emphasis of the modifications was on cutting, deflecting, and/or holding several different classes of trash. At the same time, the agronomically desirable characteristics of groove formation and seed placement were retained. Although all the modifications were of limited value by themselves, a number of important principles were demonstrated with regard to the interrelationship of rolling and non-rolling components. Trash could not be cleared with non-rolling components, spaced 150 mm apart, in a wide range of conditions unless these components were in at least partial and intimate contact with accompanying discs. Also discs could not be relied on to cut all trash, but a proportion of trash could be expected to deflected rather than cut. These principles suggested several avenues of development for future coulter designs including non-rolling components. © 1979 Taylor & Fracis Group, LLC.