AN EVALUATION OF SEED FURROW SMEARING

Seed furrow sidewall smearing describes compaction of soil in the seed zone that is caused, in some soil conditions, by the planter furrow o pener and that may interfere with crop stand establishment. Soil smear ing caused by planting with double disk furrow openers was investigate d by measuring physical properties of soil in the seed furrow and by e valuating corn (Zea mays, L.) emergence and growth. Planter attachment s for row preparation (no-coulter; single offset bubble coulter; and t riple offset fluted coulter planter attachments) were evaluated for th eir influence on seed furrow sidewall smearing over a range of soil mo isture 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 clo sed tended to decrease with increasing soil moisture. The triple-coult er treatment resulted in greater air permeability than did other coult er treatments. Soil penetration resistance below the seed and in the s eed furrow sidewall was greatest for the single coulter and least for the triple coulter. We observed that more roots grew parallel to the s oil surface with no-coulter and single-coulter treatments than with th e triple-coulter treatment especially when soil property measurements indicated that more sidewall smearing had occurred. This research show ed 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.