With the increasing size of farm equipment, the potential for soil compaction has become a real problem. According to some grain farmers, compaction from manure spreading equipment is a factor limiting their acceptance of slurry as a soil building and soil fertility resource. To address the issue of compaction caused by manure spreaders, eight on-farm sites were set up in the fall of 2004 and spring of 2005. At each site three treatments were applied (manure, farmer’s check, and tanker compaction only), and replicated three times. In addition to the on-farm trials, an onstation site was set up in Arlington. The on-station site examined the impact of multiple passes of heavy slurry equipment as might occur on field roads or headlands. After one year of field trials, it appears that compaction from manure spreaders does not adversely affect corn yields when it is applied in reasonably dry conditions. There was no significant difference between the three treatments in seven of the eight on-farm sites. Despite non-significant differences at the plot scale, hand harvests of the on-station trial showed a 10 to 15% reduction in corn yield for rows that were directly within the tire track when there were multiple passes.