Seed furrow sidewall smearing describes compaction of soil in the seed zone that is caused, in some soil
conditions, by the planter furrow opener and that may interfere with crop stand establishment. Soil smearing caused by
planting with double disk furrow openers was investigated by measuring physical properties of soil in the seed furrow and
by evaluating corn (Zea mays, L.) emergence and growth. Planter attachments for row preparation (no-coulter, single
offset bubble coulter, and triple offset fluted coulter planter attachments) were evaluated for their influence on seed furrow
sidewall smearing over a range of soil moisture contents. Planting tended to reduce soil bulk density in the 0 to 100 mm
layer in the seed zone. In general, the soil was least dense when the triple-coulter attachment was used. Air permeability
of soil samples taken from the seed furrow sidewall, before the furrow was closed, tended to decrease with increasing soil
moisture. The triple-coulter treatment resulted in greater air permeability than did other coulter treatments. Soil
penetration resistance below the seed and in the seed furrow sidewall was greatest for the single coulter and least for the
triple coulter. We observed that more roots grew parallel to the soil surface with no-coulter and single-coulter treatments
than with the triple-coulter treatment especially when soil property measurements indicated that more sidewall smearing
had occurred. This research showed that row preparation by coulter planter attachments placed ahead of double-disk
openers can reduce seed furrow sidewall smearing and may improve stand establishment of corn.