^{Agricultural soils are a major source of nitrous oxide (N₂O) which contributes to global warming and ozone depletion. The objective of this research was to establish the relationship between soil N₂O flux, temperature, soil NO₃-}-N, and soil water content and to compare the performance and cost-effectiveness of polymer-coated urea and conventional N fertilizers in relation to soil gaseous N losses. A two-year field trial planted to corn was started in 2004 at the University of Missouri Ross Jones Farm in Northeast Missouri on a claypan soil. Treatments consisted of 46 m long plots with: i) no drainage or subirrigation, ii) drainage with tile drains spaced 6 m apart and no subirrigation, iii) drainage with tile drains spaced 6 m apart and subirrigation, and iv) no drainage and overhead irrigation. The plots were split into N fertilizer treatments of broadcast pre-plant-applied urea or polymer-coated urea at rates of 0, 140, and 280 kg N ha-1. For each treatment combination there were 4 replications. The results show that in the relatively high rainfall year of 2004, corn grain yield increased in the polymer-coated urea- treated plots with no drainage or irrigation. Nitrate-N was generally higher in the urea-treated plots at the beginning of the season but was lower later in the season. In comparison, soil N₂O loss was affected by changes in soil temperature and water content due to rainfall and the different drainage and irrigation treatments. The measured soil N₂O flux was highly variable, but polymer-coated urea reduced N₂O flux in plots with no drainage and overhead irrigation. The results of this research suggest that polymer-coated urea may reduce soil N loss compared to conventional urea under relatively wet conditions, but additional evaluation must be conducted to determine whether this N fertilizer source is cost-effective for agronomic crops.