Nitrogen‐15 evaluation of fertilizer placement at planting for corn production

Abstract Numerous studies have been reported to ascertain the benefits of starter fertilization for corn ( Zea mays L.) production, but most rely on data collected by measuring early growth or grain yield at harvest. As a more conclusive evaluation, five field trials were conducted using 15 N‐labeled urea‐ammonium nitrate (UAN) solution (90 kg N ha −1 ) compare single and dual subsurface band placement, as well surface dribble broadcasting with incorporation. Significant differences in dry matter production total uptake occurred between fertilized unfertilized treatments, not among different placements studied. In contrast, fertilizer efficiency (F NUE) tended be greater either type banding than treatment, demonstrating added sensitivity that can achieved through isotopic measurements. More importantly, placement consistently outperformed broadcasting, according estimates F NUE aboveground biomass ranged from 11% 46% when UAN was banded 7% 34% broadcast applications.