HUBEI AGRICULTURAL SCIENCES ›› 2020, Vol. 59 ›› Issue (15): 60-65.doi: 10.14088/j.cnki.issn0439-8114.2020.15.011

• Resource & Environment • Previous Articles     Next Articles

Effects of cover plant in winter on soil CH4 and N2O emission under the ratoon rice system

LYU Ze-fanga,b, GAO Zhen-zhena, LIU Zhang-yonga, JIN Taoa   

  1. a. Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education;
    b. College of Horticulture and Gardening,Yangtze University, Jingzhou 434025, Hubei, China
  • Received:2020-05-20 Online:2020-08-10 Published:2020-09-24

Abstract: In order to study the effects of cover plant in winter on the CH4 and N2O emissions from ratoon rice system, the CH4 and N2O flux was observed by the static closed chamber-gas chromatography method under the treatment of ratoon rice-fallow (CK), ratoon rice-rapeseed (FR), and ratoon rice-milk vetch (MR), respectively. Results showed that the CH4 and N2O flux of all treatments was low in the winter cover plant growing season, and was high in the rice growing season. The cumulative CH4 emissions in the main rice growing season occupied 85.89% to 97.48% of annual cumulative CH4 emissions. During the main rice growing season, the cumulative CH4 emissions in the treatment of MR was significantly lower than that in the treatment of CK and FR. Over the ratoon season, there was no significant difference in the cumulative CH4 emissions among each treatment, and which occupied 2.02% to 14.11% of annual cumulative CH4 emissions. The cumulative N2O emissions in the main rice growing season was 1.74 to 2.43 times of ratoon season. The cumulative N2O emissions of MR was significantly lower than that of CK in the main rice season, and there was no significant difference in the cumulative N2O emissions among each treatment in the ratoon season. The total annual global warming potential (GWP) of CH4 and N2O for each treatment was in decreased order of FR, CK, MR. And the GWP of CH4 and N2O in the rice growing season was significantly higher than that in the winter cover plant growing season. Meanwhile, the contribution of CH4 emission to GWP in rice growing season was much higher than that of N2O. Therefore, the main rice season is the key season for reducing the greenhouse gas emissions. And plant milk vetch in the winter season could reduce the CH4 and N2O emissions under the ratoon rice system compare plant rapeseed or fallow.

Key words: ratoon rice(Oryza sativa L.), rapeseed(Brassica napus L.), milk vetch(Astragalus sinicus Linn.), fallow, greenhouse gas

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