Effects on crop growth and soil properties of machinery traffic on both, one, neither side, or on top of corn rows were studied in no-till and chiseled plots over three crop seasons. Corn in no-till plots emerged better than in chiseled plots. Generally effects on corn growth of machinery traffic in the row middles (inter-rows) were not significant. Traffic on the row before planting created planting and, consequently, emergence difficulties. Tilling the inter-rows right after planting covered some seeds too deep and resulted in delayed emergence. The delays in emergence were reflected at later stages of crop growth. Corn yields were similar for most of the tillage and traffic treatments;Soil penetration resistance was consistently greater in no-till than in chiseled plots; however, the increased soil strength did not produce any adverse effect on the crop. Parallel use of bulk density and soil penetration resistance techniques was considered desirable to characterize soil compaction;No cumulative effects of traffic, which consisted of up to ten tractor passes a year, on crop growth could be seen after three years.