1. Field Measurements of Nitrous Oxide Emissions across a Nitrogen Fertilizer Gradient for Corn Cropping Systems

Significant reductions in nitrous oxide (N 2O) emissions from corn (Zea maize L.) cropping systems may be possible by reducing N fertilizer i nputs with relatively little impact on crop grain yield or economic return. To te st this hypothesis, experiments we re conducted at 4 locations in corn production in Michigan in 2007. All sites were under a corn-soybean rotation. Prior to planting, six rates of urea fertilizer (0-200 lb ac -1) were broadcast and incorporated into four replicate plots (RCBD)...