Emission levels of nitrous oxide (N2O), one of agriculture’s most potent greenhouse gases, vary widely across Asia’s diverse climates and farming systems. To strengthen APO members’ ability to measure and mitigate these emissions, the APO Center of Excellence on Climate-smart Agriculture, hosted by the National Agriculture and Food Research Organization (NARO), Japan, held an international workshop in Tsukuba and Sakura, Japan, 25–28 November 2025. This followed data analysis activities conducted by two resource persons from 10 to 21 November. The event marked the expansion of the Center of Excellence’s focus to include N2O, following its earlier work on CO2 and greenhouse gas visualization tools.

Eighteen experts from 11 APO member economies joined the workshop, which focused on improving national N2O inventories through regional meta-analysis, better data visualization, and stronger technical skills for using emission models. Sessions covered biochar carbon credit methodologies, soil carbon mapping, and agricultural residue burning, which are key topics for future mitigation planning. Field visits to Center of Excellence biochar research facilities allowed participants to see technologies firsthand, reinforcing a practical understanding of how management practices influence N2O emissions. The workshop generated evidence that will help APO members refine and improve their national greenhouse gas inventories.