摘要
N_(2)O是一种重要的温室气体,农田是其主要排放源之一。探究N_(2)O减排潜力不仅可为农田碳减排措施提供理论和技术支持,还可为我国“双碳”目标的实现提供科学依据。为减少吉林省的N_(2)O排放量,本文根据吉林大学功能农业基地(珲春)温室气体排放数据,利用脱氮-分解作用(DNDC)模型进行点位模拟、结果验证和敏感度分析。同时,对吉林省1991—2020年玉米种植条件下N_(2)O的排放情况进行区域模拟,得到农田N_(2)O排放的时空特征,并提出增产减排的优化措施。研究结果表明:DNDC模型对吉林省农田N_(2)O排放的模拟效果较好;各因素中对N_(2)O排放量的影响程度最大的为氮肥施用量,其次是有机肥施用量,土壤有机碳质量分数也会对N_(2)O排放量有一定影响,温度、降雨量和秸秆还田比例对N_(2)O排放量影响较小;玉米种植条件下西部N_(2)O排放量最多,中部居中,东部最少。为合理控制全省农田的N_(2)O排放量,不同区域应进行不同的田间管理,西部、中部、东部最佳施氮量分别为400、330、480 kg/hm^(2),最佳基追肥施用比例分别为7∶3、9∶1、9∶1;秸秆还田比例对于N_(2)O排放量影响较小;保证产量的同时,降低土壤有机碳质量分数可以减少农田N_(2)O排放量。
N_(2)O is an important greenhouse gas,and farmland is considered to be one of the major sources of its emission.Exploring the reduction potential of N_(2)O not only provides theoretical and technical support for farmland carbon emission reduction measures,but also provides a scientific basis for the realization of China's"double carbon"goal.In order to reduce N_(2)O emissions in Jilin Province,the denitrification-decomposition(DNDC)model was used for point simulation,result verification and sensitivity analysis based on the data of greenhouse gas emissions from Jilin University Functional Agriculture Base(Hunchun).At the same time,the N_(2)O emissions were simulated from 1991 to 2020 under the conditions of corn planting in Jilin Province,its temporal and spatial characteristics were obtained,and the optimization measures for increasing corn production and reducing N_(2)O emissions were proposed.The result shows that the DNDC model was effective in the simulation of N_(2)O emissions from farmland in Jilin Province.Among all the factors,nitrogen fertilizer application rate had the greatest influence on N_(2)O emission,followed by organic fertilizer application rate,soil organic carbon content also had a certain infulence on N_(2)O emission,while temperature,rainfall and proportion of straw returning to field had little influcence on N_(2)O emission.As a result of corn cultivation,N_(2)O emissions are highest in the west,middle in the central region and lowest in the east.In order to reasonably control N_(2)O emissions from farmland in Jilin Province,different field management should be carried out in different regions,and the optimal nitrogen application rates are 400,330 and 480 kg/hm^(2)with the best base to topdressing application ratios of 7∶3,9∶1 and 9∶1 in the west,central and east,respectively.The proportion of straw returned to the field has little effect on N_(2)O emissions.While maintaining production,reducing the mass fraction of organic carbon can decrease N_(2)O emissions from agricultural land.
作者
赵玉岩
于千晴
汤肖丹
宋美彤
李兵
Zhao Yuyan;Yu Qianqing;Tang Xiaodan;Song Meitong;Li Bing(College of GeoExploration Science and Technology,Jilin University,Changchun 130026,China)
出处
《吉林大学学报（地球科学版）》
CAS
CSCD
北大核心
2023年第6期1917-1927,共11页
Journal of Jilin University：Earth Science Edition
基金
中国工程院战略研究与咨询项目(2023-DFZD-12)。
