中国水稻科学 ›› 2022, Vol. 36 ›› Issue (5): 543-550.DOI: 10.16819/j.1001-7216.2022.210811

• 研究报告 • 上一篇    

秸秆还田下大气CO2浓度升高对水稻生长和CH4排放的影响

曾文静, 邱岚英, 陈俊杰, 钱浩宇, 张楠, 丁艳锋, 江瑜()   

  1. 南京农业大学,南京 210095
  • 收稿日期:2021-08-19 修回日期:2022-03-06 出版日期:2022-09-10 发布日期:2022-09-09
  • 通讯作者: 江瑜
  • 基金资助:
    国家自然科学基金资助项目(32022061);中央高校基本科研业务费资助项目(KJYQ202101)

Effect of Elevated CO2 Concentration on Rice Growth and CH4 Emission from Paddy Fields Under Straw Incorporation

ZENG Wenjing, QIU Lanying, CHEN Junjie, QIAN Haoyu, ZHANG Nan, DING Yanfeng, JIANG Yu()   

  1. Nanjing Agricultural University, Nanjing 210095, China
  • Received:2021-08-19 Revised:2022-03-06 Online:2022-09-10 Published:2022-09-09
  • Contact: JIANG Yu

摘要:

【目的】明确秸秆还田下大气CO2浓度升高对水稻生长和稻田CH4排放的影响,为气候变化下温室气体排放评估和丰产低碳的稻作技术创新提供理论参考和科学依据。【方法】利用开顶式气室(Open top chamber, OTC)进行田间试验,设置两个CO2浓度处理,分别为正常大气CO2浓度处理(简称aCO2,CO2浓度约为0.04%)和大气CO2浓度升高处理(简称eCO2,CO2浓度约为0.055%),每个处理的田块混入等量的前茬小麦秸秆,探明秸秆还田下大气CO2浓度升高对水稻产量等生长特性、稻田CH4排放及微生物丰度的影响,揭示秸秆还田下大气CO2浓度升高对CH4排放的影响机制。【结果】大气CO2浓度升高显著促进水稻的生长,使剑叶叶面积增加25.0%,地上生物量增加22.0%,产量提高29.0%。大气CO2浓度升高显著增加了穗数、结实率和千粒重,但对穗粒数影响不显著。秸秆还田下,大气CO2浓度升高有降低稻田CH4排放的趋势,使单位产量CH4排放量降低了39.4%。大气CO2浓度升高使土壤甲烷氧化关键基因pmoA的拷贝数增加了20.0%,但对甲烷产生关键基因mcrA的拷贝数影响较小。【结论】秸秆还田条件下,未来大气CO2浓度升高不仅提高了水稻产量,而且有利于减少稻田温室气体CH4的排放。

关键词: 大气CO2升高, 秸秆还田, 温室气体, 水稻产量, 甲烷排放

Abstract:

【Objective】The aim of this study is to clarify the effects of increased atmospheric CO2 concentration on rice growth and CH4 emission under straw incorporation, so as to provide theoretical reference and lay a scientific basis for greenhouse gas emission assessment for rice production technology innovation concerning high yield and low carbon emission under climate change. 【Method】Field experiments were conducted in Open Top Chambers (OTC). Two CO2 concentrations were designed, namely, ambient atmospheric CO2 concentration (0.04%, aCO2) and elevated atmospheric CO2 concentration (0.055%, eCO2) with an equal amount of previous wheat straw incorporation. We analyzed the effects of eCO2 concentration on rice yield and growth, CH4 emission and the abundance of related microorganisms from paddy fields under straw incorporation, which could illustrate the influence mechanism of eCO2 on CH4 emission under that conditions. 【Result】The results showed that eCO2 significantly promoted rice growth, i.e., eCO2 increased flag leaf area, aboveground biomass and rice yield by 25.0%, 22.0%, and 29.0%, respectively. Elevated atmospheric CO2 concentration significantly increased the number of panicles, seed setting rate and 1000-grain weight, but eCO2 have no effect on the number of grains per panicle. Under straw incorporation, eCO2 trended to mitigate the CH4 emission from rice paddies and reduced the yield-scared CH4 emission by 39.4%. Elevated atmospheric CO2 concentration increased the copy numbers of pmoA, a key gene for methane oxidation in soil, by 20%, but had little effect on the copy number of mcrA, a key gene for methane production. 【Conclusion】Under the straw incorporation, eCO2 not only improves rice yield but also reduces CH4 emission from rice paddies.

Key words: elevated atmospheric CO2, straw incorporation, greenhouse gase, rice yield, methane emission