Winter cover crops alter methanotrophs community structure in a double-rice paddy soil  

作　　者：LIU Jing-na ZHU Bo YI Li-xia DAI Hong-cui XU He-shui ZHANG Kai HU Yue-gao ZENG Zhao-hai 

机构地区：[1]College of Agriculture and Biotechnology, China Agricultural University [2]School of Agronomy, Yangtze University

出　　处：《Journal of Integrative Agriculture》2016年第3期553-565,共13页农业科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (31171509 and 30671222);the Special Fund for Agro-scientific Research in the Public Interest, China (201103001);the National Key Technology R&D Program for the 12th Five-Year Plan period (2011BAD16B15)

摘　　要：Methanotrophs play a vital role in the mitigation of methane emission from soils. However, the influences of cover crops incorporation on paddy soil methanotrophic community structure have not been fully understood. In this study, the impacts of two winter cover crops（Chinese milk vetch（Astragalus sinicus L.） and ryegrass（Lolium multiflorum Lam.）, representing leguminous and non-leguminous cover crops, respectively） on community structure and abundance of methanotrophs were evaluated by using PCR-DGGE（polymerase chain reaction-denaturing gradient gel electrophoresis） and real-time PCR technology in a double-rice cropping system from South China. Four treatments were established in a completely randomized block design： 1） double-rice cropping without nitrogen fertilizer application, CK; 2） double-rice cropping with chemical nitrogen fertilizer application（200 kg ha^（–1） urea for entire double-rice season）, CF; 3） Chinese milk vetch cropping followed by double-rice cultivation with Chinese milk vetch incorporation, MV; 4） ryegrass cropping followed by double-rice cultivation with ryegrass incorporation, RG. Results showed that cultivating Chinese milk vetch and ryegrass in fallow season decreased soil bulk density and increased rice yield in different extents by comparison with CK. Additionally, methanotrophic bacterial abundance and community structure changed significantly with rice growth. Methanotrophic bacterial pmo A gene copies in four treatments were higher during late-rice season（3.18×10^7 to 10.28×10^7 copies g^–1 dry soil） by comparison with early-rice season（2.1×10^7 to 9.62×10^7 copies g^–1 dry soil）. Type Ⅰ methanotrophs absolutely predominated during early-rice season. However, the advantage of type Ⅰ methanotrophs kept narrowing during entire double-rice season and both types Ⅰ and Ⅱ methanotrophs dominated at later stage of late-rice.Methanotrophs play a vital role in the mitigation of methane emission from soils. However, the influences of cover crops incorporation on paddy soil methanotrophic community structure have not been fully understood. In this study, the impacts of two winter cover crops（Chinese milk vetch（Astragalus sinicus L.） and ryegrass（Lolium multiflorum Lam.）, representing leguminous and non-leguminous cover crops, respectively） on community structure and abundance of methanotrophs were evaluated by using PCR-DGGE（polymerase chain reaction-denaturing gradient gel electrophoresis） and real-time PCR technology in a double-rice cropping system from South China. Four treatments were established in a completely randomized block design： 1） double-rice cropping without nitrogen fertilizer application, CK; 2） double-rice cropping with chemical nitrogen fertilizer application（200 kg ha^（–1） urea for entire double-rice season）, CF; 3） Chinese milk vetch cropping followed by double-rice cultivation with Chinese milk vetch incorporation, MV; 4） ryegrass cropping followed by double-rice cultivation with ryegrass incorporation, RG. Results showed that cultivating Chinese milk vetch and ryegrass in fallow season decreased soil bulk density and increased rice yield in different extents by comparison with CK. Additionally, methanotrophic bacterial abundance and community structure changed significantly with rice growth. Methanotrophic bacterial pmo A gene copies in four treatments were higher during late-rice season（3.18×10^7 to 10.28×10^7 copies g^–1 dry soil） by comparison with early-rice season（2.1×10^7 to 9.62×10^7 copies g^–1 dry soil）. Type Ⅰ methanotrophs absolutely predominated during early-rice season. However, the advantage of type Ⅰ methanotrophs kept narrowing during entire double-rice season and both types Ⅰ and Ⅱ methanotrophs dominated at later stage of late-rice.

关 键 词：Chinese milk vetch ryegrass methanotrophic bacteria community structure double-rice 

分 类 号：S154.36[农业科学—土壤学]