Soil Compaction from Front and Rear Tires of an MFWD Tractor

Soil bulk density and cone index were measured just above a hardpan beneath the centerlines of tires representative of front and rear tires of a mechanical front wheel drive (MFWD) tractor with dual rear tires. A 14.9R30 R-1 front tire and an 18.4R42 R-1 rear tire were operated on a sandy loam and a clay loam soil with loose soil above hardpans in soil bins, using three combinations of dynamic load and inflation pressure representative of a tractor hitched to a row-crop planter. When the tractor is used with either an integral planter with liquid chemical carried on the tractor, or a towed planter without liquid chemical carried on the tractor, the front tires are the major source of soil compaction caused by tractor tires. A tractor configured for use with a towed planter without liquid chemical carried on the tractor causes less soil compaction beneath the tractor tires than a tractor configured for an integral planter with liquid chemical carried on the tractor.