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基于田间原位测定结果,作者建立了不同水分管理方式下稻田N2O排放估算的统计模型.在模型验证和输入参数检验的基础上,本研究应用模型估算了20世纪50~90年代我国稻田水稻生长季N2O直接排放量.结果表明,由于水稻种植面积和氮输入量的增加、以及水分管理方式的变化,稻田N2O-N季节排放量从20世纪50年代平均每年9.55 Gg增加到了90年代每年32.26 Gg,同期伴随着水稻单产的增加.在20世纪50~90年代间,我国水稻生产的N2O-N排放量以平均每10 a 6.74 Gg的速度递增.20世纪50年代和90年代稻田N2O-N季节排放通量平均分别为0.32 kg.hm-2和1.00 kg.hm-2,相当于季节氮输入总量的0.37%和0.46%.本研究模型估算50~90年代间稻田N2O季节排放量的不确定性为59.8%~37.5%.就全国稻田的不同种植区域而言,长江中下游地区稻田水稻生长季N2O排放量占全国稻田N2O排放总量的51%~56%.20世纪90年代水稻生长季N2O排放量约占我国农田N2O年总排放量的8%~11%.相对于旱地作物而言,过去几十年水稻生产的发展在很大程度上减缓了我国农业生产的N2O排放.然而,随着水稻生产中节水灌溉的推广和氮肥施用量的增加,我国稻田N2O季节排放量预计将相应增加.
Based on the in situ field measurements, the authors established a statistical model for estimation of N2O emissions from paddy fields under different water management practices.On the basis of model validation and input parameter verification, this study estimated the rice growth in paddy fields from 1950 to 1990 in China Season N2O emissions.The results showed that the seasonal emissions of N2O-N in paddy fields increased from 9.55 Gg per year in the 1950s to 32.26 Gg / year in the 1990s due to the increase of rice acreage and nitrogen input, and the change of water management methods. With the increase of rice yield in the same period.During the 1950s and 1990s, the N2O-N emission of rice production in our country increased at an average rate of 6.74 Gg every 10 years. In the 1950s and 1990s, the N2O-N season The average discharge flux was 0.32 kg.hm-2 and 1.00 kg.hm-2, respectively, which was equivalent to 0.37% and 0.46% of the total seasonal nitrogen input.The estimation of N2O season emissions from paddy field in the 1950 ~ With a certainty of 59.8% -37.5% .In the different growing areas of the rice fields in the country, the N2O emissions in paddy rice growing season in the middle and lower reaches of the Yangtze River account for 51% -56% of the total N2O emissions in the national rice paddies. Quarter N2O row Which accounts for about 8% ~ 11% of the total annual N2O emissions from farmland in China. Compared with dryland crops, the development of rice production in the past few decades has greatly slowed down N2O emissions from agricultural production in our country. However, The promotion of water-saving irrigation in rice production and the increase of nitrogen fertilizer application are expected to increase the seasonally discharged amount of N2O in paddy fields in China.