Compaction of soil by heavy field equipment is a major cause of degradation in soil quality world-wide. As fields get bigger to benefit from economies of scale, so do field vehicles and machinery, and inevitably there is more compaction. Compaction compresses the large, aeration pores (those that drain by gravity); that makes soil more difficult to work (so more fuel is required), retards root growth, and impedes oxygen movement (which reduces nutrient uptake efficiency so that more ferilizer has to be used; reduced oxygen also stimulates root pathogens).

There are two general approachs to alleviating the problem: (i) use of smaller, lighter weight machinery (usually on smaller field units); or use of larger machinery with a wide wheel base combined with restricting wheels to the same tracks in successive operations. The photos at right illustrate examples of each approach.