Furrow openers using single disc coulter operated at certain disc and tilt angles are becoming common for single pass seeding operation. Concerns have been expressed as to the efficiency of disc to place seed and fertilizer at a proper depth, and resulting compaction of the furrow wall. Tests were conducted in an indoor soil bin using 460 mm (18-in.), and 610 mm (24-in.) diameter disc coulters to determine the effect of combined disc and tilt angles on soil forces, and resulting furrow wall strength. Experiments were carried out using various levels of combined disc angles, moisture content, soil compaction, and depth of operations. Measurements were taken for draft, vertical force, side force, soil strength of the furrow wall, and furrow profile. Results indicated that the most favorable condition in terms of the lowest values of draft, vertical force, side force, and soil strength of the furrow wall were obtained with 610 mm diameter disc at 5°&15° combined angle. However, for 460 mm diameter disc, the lowest values of draft and side forces were obtained with 5°&15° and 5°&25° combined angles, respectively. |