On-farm evaluations of twin-row production systems have been studied since 2005 with significant yield responses achieved with increasing nitrogen (N) rates and seeding rates.  The biggest question from producers relates to the comparison of twin-row (TR) planting compared to single-row (SR) planting on wide rows (96 to 102 cm).  A multiple-year research project was established in 2007 to evaluate the interaction of nitrogen (N) rates (202, 246, and 291 kg N ha^-1) with four seeding rates (61,775 to 98.84 seeds ha^-1) for both TR and SR corn production on 102-cm beds.  The study was planted on Bosket very fine sandy loam, following soybean, with a MonosemJ twin-row vacuum planter and a John Deere 7300 vacuum planter.   Nitrogen was applied as urea-ammonium nitrate solution (32% N) prior to planting (134 kg N ha^-1) with the rates established at the time of sidedress application.  Root lodging was evident midway through the growing season and increased as seeding rates increased especially for the SR system.  At the highest seeding rate, root lodging was 60% (SR) and 40% (TR).  With the SR system, yields were not significantly increased with the increased seeding rates.  However, lodging increased from 2% to 60% as the seeding rate increased.  For the TR system, grain yields increased from 13.9 to 15.3 Mg ha^-1 as the seeding rate increased from 71,000 plants ha^-1 to 95,900 plants ha^-1.  Grain yield response to increasing N rate was not significant, but this lack of significance can be related to the early root lodging that occurred.  This study will be repeated with additional emphasis on planter calibration.  With the twin-row planter, actual stand counts showed a 10.4 to 17.1% increase in plants ha^-1 compared to the planter book estimates.  With the continued increases in seed costs, careful planter calibration is important.