Abstract: In this research, the amount of greenhouse gas emissions from fertilization, production and transportation of synthetic nitrogen for tea garden in typical region of China was assessed based on the analysis of statistical data using a data mining method. The results show that direct N₂O emissions from soil and greenhouse gas emissions (CO₂ emission equivalents) from the production of synthetic N fertilizers were the main sources of greenhouse gas emissions from synthetic N fertilization in tea garden. In 14 typical regions, the total greenhouse gas emissions from synthetic N fertilization were 168.1-3 448.0 kt CO₂ equivalent per year. And Guizhou, Yunan, Hubei and Sichuan were the top four provinces with high greenhouse gas emissions from synthetic N fertilization. Over 2 000 kt CO₂ equivalent per year occurred in each province, which accounted for 59.98% of the total emissions. The greenhouse gas emissions per unit area, per yield and per output value was 3.22-9.76 t CO₂ equivalent per hectare, 2.10-12.96 t CO₂ equivalent per ton of dry semifinished tea and 0.39-1.90 t CO₂ equivalent per 10 000 yuan. In general, the total greenhouse gas emissions, emissions per unit area, per yield and per output value from synthetic N fertilization were mainly concentrated in Guizhou, Yunan, Hubei, Hunan and Sichuan provinces, and the relatively low total emissions and emission intensity were happened in Fujian, Henan provinces and Chongqing city. It was concluded that reducing the synthetic N application rate for tea garden in China to a reasonable level of 300 kg·hm^-2 and 450 kg·hm^-2 could greatly reduce the emission of greenhouse gases. And the estimated mitigation potential of greenhouse gas emissions for these provinces were 6 170.7, 2 289.4 kt CO₂ equivalent per year, and reduce the total greenhouse gas emissions by 34.12% and 12.66%. Notably, Hubei, Sichuan, Guizhou, Hunan and Jiangxi provinces were the leaders of the mitigation potential of greenhouse gas emissions, and these areas should focus on reducing greenhouse gas emissions.

Key words: tea garden, synthetic nitrogen fertilizers, greenhouse gas emissions, mitigation potential