资源科学 ›› 2019, Vol. 41 ›› Issue (7): 1286-1294.doi: 10.18402/resci.2019.07.09

• 碳排放 • 上一篇    下一篇

中国南方旱田转水田后温室气体减排年限预测

赵苗苗1,3(), 邵蕊1, 李仁强1, 杨吉林2,3, 徐明1,3()   

  1. 1. 中国科学院地理科学与资源研究所 生态系统网络观测与模拟重点实验室,北京 100101
    2. 中国科学院地理科学与资源研究所 陆地表层格局与模拟重点实验室,北京 100101
    3. 中国科学院大学,北京 100049
  • 收稿日期:2017-11-07 修回日期:2019-03-06 出版日期:2019-07-25 发布日期:2019-07-25
  • 作者简介:

    作者简介:赵苗苗,女,山东郓城人,博士研究生,研究方向为资源环境与生态系统模拟。E-mail: zhaomm@lreis.ac.cn

  • 基金资助:
    国家重点研发计划项目(2017YFA0604302)

Simulation of greenhouse gas emission reduction years after the conversion of cropland into paddy field in southern China

Miaomiao ZHAO1,3(), Rui SHAO1, Renqiang LI1, Jilin YANG2,3, Ming XU1,3()   

  1. 1. Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-11-07 Revised:2019-03-06 Online:2019-07-25 Published:2019-07-25

摘要:

农业生产活动是大气温室气体的主要来源之一,不同作物栽培体系和管理方式都会影响农田温室气体的排放。国内外已有大量关于农业温室气体排放规律和控制机理的研究,但关于土地利用方式转变对温室气体排放规律和影响机制的研究相对较少。本文以中科院千烟洲红壤丘陵综合开发试验站为研究平台,通过对新(刚从旱田转为稻田)老(过去20余年一直为稻田)稻田进行连续4年(2013—2016)观测,分析稻田温室气体排放规律及影响因子。在此基础上预测稻田温室气体排放量的动态变化。研究表明,旱田转变为稻田后,前4年新稻田CH4排放通量显著低于老稻田,但随着耕作年限的延长新稻田的CH4排放速率呈增加趋势,而老稻田的CH4排放速率没有明显变化趋势;耕作年限对CO2和N2O的排放速率影响不显著;新稻田的pH值和土壤有机碳含量低于老稻田。模型模拟结果表明缩短稻田轮作(水-旱轮作)期(小于7年)能够有效降低稻田CH4和总温室气体排放量。该结果表明利用老稻田的CH4排放系数可能会显著高估新稻田的CH4排放量。研究结论可为准确评估土地利用方式变化对农业温室气体排放的影响提供新的视角,同时为区域农业温室气体管理和减排政策的制定提供科学依据。

关键词: 土地利用方式转变, 温室气体, 稻田, 年限, 轮作, 排放通量, 千烟洲

Abstract:

Agricultural production activities are one of the main sources of atmospheric greenhouse gases. Different crop cultivation systems and management methods will affect greenhouse gas emissions. There have been a lot of researches on the laws and control mechanisms of agricultural greenhouse gas emissions at home and abroad, but there are relatively few studies on the laws and influence mechanisms of greenhouse gas emissions. In this study, greenhouse gas fluxes new paddy fields (just converted from paddy fields to rice fields) in 2013-2016 and old paddy(which have been rice fields for the past 20 years) fields in 2016 as well as soil micro-meteorological and other physical and chemical properties were observed using a field plot experiment at the Qianyanzhou Ecological Station of the Chinese Academy Sciences in southern China. Then, seasonal and annual variation of greenhouse gas fluxes and the main factors that impacting greenhouse gas fluxes were analyzed. Based on the analysis, the dynamic changes of greenhouse gas emissions in rice fields are predicted. The results show that in the first four years after land-use conversion, CH4 emission fluxes in the new paddy fields were significantly lower than that in the old paddy fields, and annual emission increased with the extension of farming period, while the CH4 emission rate of old rice fields is not obvious, whereas the difference in emission of the greenhouse gases CO2 and N2O were not significant. Moreover, soil pH and the soil organic carbon content of new rice fields were lower than that of old paddy fields. The model simulation results show that shortening paddy field rotation (water-dry rotation) period (less than 7 years) can effectively reduce CH4 and total greenhouse gas emissions in paddy fields. The results suggest that using the CH4 emission coefficient of old rice fields may significantly overestimate CH4 emissions from new rice fields. This study may provide new insights for understanding the impact of land- use change on greenhouse gas emissions, and provide a basis for accurate estimation of regional agricultural greenhouse gas emissions and the development of emission reduction policies.

Key words: land-use conversion, greenhouse gases, paddy, land-use years, rotation, flux, Qianyanzhou