RELATIONSHIPS BETWEEN PARAMETERS OF COMBINE DESIGN AND SOIL COMPACTION

Field observations indicated that combines can cause soil compaction. Front axle loads of today's highest-capacity combines can be as high as 18 Mg (40,000 lb) with ground pressures exceeding 100 kPa (15 psi). Statistical results indicated that the header and grain tank are dominant factors affecting axle loads. A grading system was developed to rank combine configurations on cost, operation, performance, service, and compaction. Two alternatives might be feasible compared to a mid-capacity, standard combine: a combine with full-length tracks, and a combine/ grain cart with weight distributed on three axles. Today's largest standard combines need four axles to have acceptable axle loads and group pressures.