Effect of seedbed packing on canola seedling emergence effect of soil characteristics, seeding depth, operation speed, and opener design on direct seeding draft forces

Abstract

Direct seeding practices that promote soil and water conservation and reduce input costs have become an increasingly accepted alternative to conventional tillage systems in western Canada. The objective of the present study was to determine the relative importance of soil characteristics, seeding depth, operation speed, and opener design on direct seeding draft forces. Draft was measured for nine different openers operated at one to five cm seeding depths and three ground speeds in four non-tilled fields that differed in soil moisture and/or texture. The average increase in opener draft for all fields was four percent for each km h-1 increase in speed. Although the range in soil consistence was small, there was a 24 percent increase in draft in heavy clay compared to sandy loam soil. Draft force of the average opener increased by nearly 20 percent for each cm increase in seeding depth. However, there were large differences in the performance of different openers operated at different depths in soils with different consistence. A 4.5-fold increase in the draft of a low draft versus a high draft opener operated at 1.25 versus 5.0 cm seeding depth at 7.5 km h-1 in moist, heavy clay soil emphasized the large influence that opener design and seeding depth have on tractor power requirements and direct seeding input costs.