Effect of Different Nitrogen Fertilizations On Ammonia and Greenhouse Gas Emissions From a Sub-Tropical Wheat Field.

Different agricultural management practices likely influence air quality and greenhouse gas emissions. In this study, effect of urea, coated urea and ammonia sulfate application on NH₃ and greenhouse gas (CO₂, CH₄ and N₂O) emissions in subtropical wheat production were evaluated. Field emissions of NH3 and greenhouse gases were sampled based on active and passive chamber methods, respectively.  Results showed that N fertilization generally increased the emission of N₂O and CO₂ while no significant CH₄ emission was observed. Urea treatment yielded more N₂O emission than ammonia sulfate and coated urea treatments whereas ammonia sulfate application increased CO₂ respiration compared to same rate of urea. In addition, N₂O and CO₂ emissions were affected by the application rate, precipitation, soil moisture and temperature. Overall, the results suggest that coated urea along with the proper application time have the potential to reduce greenhouse gas emissions.