Enhanced Efficiency Fertilizer Impacts on Yield-Scaled Nitrous Oxide Emissions in Maize.

A two year field experiment was conducted to assess the ability of enhanced efficiency nitrogen sources to minimize yield-scaled N₂O emissions while increasing nutrient utilization and crop productivity in maize production systems in Illinois. In addition to an unfertilized control (zero N), the following four N source treatments were applied at 202 kg ha^-1 at planting: anhydrous ammonia, UAN + nitrapyrin, ESN, and SuperU. Gas samples were collected using static closed chambers. Soil inorganic N concentrations, soil moisture and temperature, and precipitation were monitored throughout the growing season. Although findings are preliminary, results indicate that enhanced efficiency N sources did not consistently reduce N₂O emissions or increase yield relative to the anhydrous ammonia treatment. In year 1, injected UAN + nitrapyrin increased N₂O and yield-scaled N₂O emissions relative to the other N sources. An analysis of two years of data will be presented.