Study explores how to reduce GHG emissions while supporting food security through nitrogen management
Responses of yields and N₂O emissions to N inputs could be used to design appropriate N management strategies for addressing the dual challenge of food insecurity and climate crisis.
November 25, 2022
Use of fertilizer nitrogen (N) in farming is essential for food production but also contributes to climate crisis through GHG emissions. Synthetic nitrogen fertilizer accounts for 2.4 percent of global emissions, while its supply chain accounts for 21.5% of the annual direct emissions from agriculture.
One potential solution for developing appropriate N management strategies is yield-scaled nitrous oxide (N₂O) emission (YSNE), which has been recognized for its potential to balance food security and mitigate emissions. Improving understanding and use of YSNE under various field conditions is an essential part of widespread adoption of this approach.
Type 1 measures: increasing yields without changing N₂O emissions. Type 2 measures: reducing N₂O emissions without changing yields. Type 3 measures: both increasing yields and reducing N₂O emissions. (Photo: CIMMYT)
A positive relationship between N inputs and YSNE was evidenced in more than 60% of the dataset across all three crops, while a small proportion had an optimum N rate that minimized YSNE. Type of crop, annual mean temperature and soil N content affected the background yield-scale N₂O emission with higher soil temperature and N content leading to higher BYSNE. The analyses suggest that YSNE can be reduced by increasing yields, by reducing N₂O emissions and both by increasing yields and reducing N₂O emissions. The results of this study suggest appropriate N management strategies, yields, and N2O emissions.