关键词: 抑制剂, 缓（控）释肥, 减少施氮量, N₂O, 减排潜力

Abstract:

Upland croplands are the main source of N₂O emissions. Mitigation of N₂O emissions from upland croplands will greatly contribute to an overall reduction of greenhouse gases from agriculture. Using 355 datasets extracted from 103 publications, a Meta-analysis was performed to investigate the mitigation options and potential of N₂O emissions from wheat and maize fields in China. The results showed that application of inhibitors in wheat and maize fields reduced 36%-46% of the N₂O emissions with an increase in crop yield. Cutting the application rates of nitrogen fertilizers by no more than 30% could reduce N₂O emissions by 10%-18% without crop yield loss. Applications of slow (controlled-) release fertilizers and incorporations of crop residues could significantly mitigate N₂O emissions from wheat fields, but the mitigation was not statistically significant in maize fields. The gross N₂O emissions could be reduced by 9.29-13.90 Gg N₂O-N per wheat season and 10.53-23.19 Gg N₂O-N per maize season when different mitigation options were put into practices. The mitigation potential (MP) in wheat cultivation was particularly notable for Henan, Shandong, Hebei and Anhui provinces, accounting for 53% of the total MP in wheat fields. Heilongjiang, Jilin, Shandong, Hebei and Henan provinces showed high MP in maize cultivation, accounting for approximately 50% of the total MP in maize fields.

Key words: inhibitor, slow (controlled-) release fertilizer, reducing nitrogen rate, nitrous oxide, mitigation potential