Depth Wheel Misadjustment and Fluctuating Tillage Depth on Reversible Ploughs

A plough that cuts one furrow deep and the next shallow usually points at the depth wheel rather than the bodies. The depth wheel carries part of the plough's weight and sets the working depth. When it is set wrong or worn, the plough floats up and down through the pass, and the field finishes with a patchy cut. A short adjustment restores even depth.

How the depth wheel sets the cut

The depth wheel runs beside the furrow and sets how low the plough frame sits. Raise the wheel and the plough cuts deeper; lower it and the cut becomes shallower. On reversible ploughs, the wheel must be centered so that both directions cut to the same depth. A wheel that leans to one side makes one pass deeper than the other.

Check the wheel and tyre condition

A flat or worn tyre on the depth wheel changes its effective height, which quietly changes depth from one day to the next. Inspect the tyre for pressure and wear, and check the wheel bearing for play. A wobbly wheel lets the plough bob through the pass, even if the adjustment itself is correct. Grease the wheel bearing and confirm the mounting bolts are tight.

Set it level on firm ground

To adjust properly, park the tractor and plough on flat ground, lower the plough to working position, and measure the depth from the share point to the ground. Adjust the wheel until both sides of the frame sit level. Make a small trial pass in the field, then measure the actual furrow depth behind the plough. Fine-tune from the real measurement rather than the guess on the adjustment scale.

Match depth to the job

Different crops and soils need different working depths. Once the wheel is set for the season, mark the adjustment position with paint so that returning to the same depth next year takes seconds. Note that wet soil cuts more easily than dry, and a plough set for dry ground may run deeper when the soil is damp.

Watch for drifting depth through the season

If depth starts to vary mid-season, re-check the wheel mounting and the top link. Vibration loosens lock nuts over time, and a depth wheel that slowly drops its setting shows up as shallower work. A quick check at the start of each week catches drift before it shows in the field. With a level, firm depth wheel, the plough holds its cut pass after pass.

References

BROWN R T, DAVIES M K. Effect of depth wheel adjustment on ploughing consistency[J]. Biosystems Engineering, 2020, 198: 130-139.

Brown, R. T., and M. K. Davies. "Effect of Depth Wheel Adjustment on Ploughing Consistency." Biosystems Engineering, vol. 198, 2020, pp. 130-139.

Brown, R. T., & Davies, M. K. (2020). Effect of depth wheel adjustment on ploughing consistency. Biosystems Engineering, 198, 130-139.