April 2, 2010

Compaction from wheel traffic can be minimized by

• reducing the total axle load,
• using more axles to carry the load,
• using larger tires or wider tracks for more ground contact, and
• reducing tire inflation pressures to further increase the tire footprint.

The wider and taller a tire is, the better as it will have a larger footprint on the soil surface and spread out the weight. Large single tires are preferred over duals as duals often increase the total axle weight and have a “pinch row” between them.

Reduce tire inflation pressures to the minimum pressure required to safely carry the load. Consult your owner's manual or tire company literature to determine the minimum inflation pressures for your situation. If more load-carrying capacity is needed with mounted implements, duals may help, but lift assist wheels may be a better choice for reducing compaction and improving stability in transport.

Remember that the load on the tires may be different in the field than when the implement is folded for transport. In addition, the minimum inflation pressure increases as travel speed increases. For those really concerned about wheel traffic compaction, consider reducing tire pressure in the field and re-inflating the tires to the higher pressures required for transport.

Wheel traffic compaction and inflation pressures can be reduced by using more axles to carry the loads. Pull-type planters will create less compaction than mounted planters as the weight is reduced on the tractor. Likewise, a pull-type sprayer or a tow cart for fertilizer will have less compaction than using saddle tanks on the tractor as there are more axles carrying the load.

Controlled wheel traffic, where all the field operations are conducted using the same wheel tracks, will reduce the amount of the field being driven on, thus reducing the compacted area. Most compaction occurs on the first pass and by using the same wheel tracks, subsequent passes don’t add much compaction. Tractive efficiency and field drivability also are improved as the tires are traveling on an already firmed soil.

Paul Jasa
Extension Engineer