Study: Enhanced Efficiency Nitrogen Fertilizers were not effective in reducing N₂O emissions from drip-irrigated cotton field

Agricultural system is the major source of greenhouse gas N₂O emissions. Application of polymer-coated urea and urease and/or nitrification inhibitor has the potential in reducing soil N₂O emissions, while some inconsistent results were found with the difference in N rate, climate, crops and soil properties. Researchers found that enhanced efficiency nitrogen fertiliazers were not effective in reducing N₂O emissions from drip-irrigated cotton field in arid northwest China.

Researchers from Cele National Station of Observation and Research for Desert-Grassland Ecosystem, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, carried out two years cotton field experiment in Xinjiang to determine N₂O emissions from different fertilizer N sources (Urea, polymer-coated urea-ESN, stabilized urea with nitrification and urease inhibitors-SuperU) and rates (120 and 240 kg N ha-1).

Results show that N₂O emissions over two-year growth season were significantly increased by 29-47% in treatment of ESN or SuperU, without significant effect on cotton yield. Reducing N rate by half significantly reduced both of the N₂O emissions and cotton yield.

The efficacy of ESN and SuperU is limited, fertigation with urea at recommended rate is the best option to ensure cotton yield and mitigation in N₂O emission in this study site, scientists said.

Results of the study were published on Science of the Total Environment, entitled "Enhanced efficiency nitrogen fertilizers were not effective in reducing N₂O emissions from a drip-irrigated cotton field in arid region of Northwestern China".
Article link: https://www.sciencedirect.com/science/article/abs/pii/S0048969720350725.