中国省域农业源N2O排放清单及特征分析

Inventory and characteristics of agricultural nitrous oxide emissions in China

对中国31个省(市、自治区)2000—2016年的农业源N2O排放清单进行计算和分析。结果表明:中国(不含港、澳、台)农业源N2O排放量从2000年的71.8013×10^4 t波动增加到2016年的95.3549×10^4 t,增幅为32.80%,年均增长1.79%,其中,农用地N 2O是农业源N2O的主要来源,占农业源N 2O总排放量的63.47%~77.26%。省域农业源N 2O排放存在明显的区域差异性:广西、广东和云南的N 2O排放量最高,远高于北京、上海、天津等地。其中,农用地N2O排放以广西最高,2016年为45.3202×10^4 t,西藏最少,2016年为0.0053×10^4 t。农用地N2O排放以直接排放为主,所占比例为69%~87%。畜禽粪便管理N 2O排放以四川、河南、内蒙古、云南和山东最高,而上海、北京、天津、浙江、海南较少。

In the present study,agricultural N2O emissions inventory and characteristics of 31 provinces(municipalities,autonomous regions)were explored in 2000-2016 in China.It was shown that the agricultural N2O emission in China(Hongkong,Macao,Taiwan excluded)increased from 71.8013×10^4 t in 2000 to 95.3549×10^4 t in 2016,with an increase of 32.80% and an average annual increase of 1.79%.The N2O emission from agricultural land was the main source of agricultural N2O emission,which accounted for 63.47%-77.26%.There were obvious regional differences for the agricultural N2O emissions in 31 provinces(municipalities,autonomous regions).Guangxi,Guangdong and Yunnan showed the highest agricultural N2O emission,which was higher than that in Beijing,Shanghai and Tianjin.The highest N2O emission from agricultural land occurred in Guangxi,with an amount up to 45.3202×10^4 t in 2016,while the lowest N2O emission from agricultural land occurred in Tibet,which was 0.0053×10^4 t.Besides,the direct emission accounted for 69%-87% in the case of N2O emission from agricultural land.N2O emission from livestock and poultry manure management was relatively high in Sichuan,Henan,Inner Mongolia,Yunnan and Shandong,while it was relatively low in Shanghai,Beijing,Tianjin,Zhejiang and Hainan.