Tillage practices and straw-returning methods affect topsoil bacterial community and organic C under a rice-wheat cropping system in central China.
The objective of this study was to investigate how the relationships between bacterial communities and organic C (SOC) in topsoil (0-5 cm) are affected by tillage practices [conventional intensive tillage (CT) or no-tillage (NT)] and straw-returning methods [crop straw returning (S) or removal (NS)] under a rice-wheat rotation in central China. Soil bacterial communities were determined by high-throughput sequencing technology. After two cycles of annual rice-wheat rotation, compared with CT treatments, NT treatments generally had significantly more bacterial genera and monounsaturated fatty acids/saturated fatty acids (MUFA/STFA), but a decreased gram-positive bacteria/gram-negative bacteria ratio (G(+)/G(-)). S treatments had significantly more bacterial genera and MUFA/STFA, but had decreased G(+)/G(-) compared with NS treatments. Multivariate analysis revealed that Gemmatimonas, Rudaea, Spingomonas, Pseudomonas, Dyella, Burkholderia, Clostridium, Pseudolabrys, Arcicella and Bacillus were correlated with SOC, and cellulolytic bacteria (Burkholderia, Pseudomonas, Clostridium, Rudaea and Bacillus) and Gemmationas explained 55.3% and 12.4% of the variance in SOC, respectively. Structural equation modeling further indicated that tillage and residue managements affected SOC directly and indirectly through these cellulolytic bacteria and Gemmationas. Our results suggest that Burkholderia, Pseudomonas, Clostridium, Rudaea, Bacillus and Gemmationas help to regulate SOC sequestration in topsoil under tillage and residue systems.
MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River/College of Plant Science &Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China.
Lijin
L
Guo
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China.
Shixue
S
Zheng
MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River/College of Plant Science &Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China.|Hubei Collaborative Innovation Center for Grain Industry, Yangtze University, Jingzhou 434023, Hubei, P.R. China.
Cougui
C
Cao
MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River/College of Plant Science &Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China.|Hubei Collaborative Innovation Center for Grain Industry, Yangtze University, Jingzhou 434023, Hubei, P.R. China.
Chengfang
C
Li
D000383:Agriculture / Q000379:methods*; D001419:Bacteria / Q000235:genetics; D002244:Carbon / Q000032:analysis / Q000737:chemistry; D002681:China; D018556:Crops, Agricultural; D059014:High-Throughput Nucleotide Sequencing; D058889:Molecular Typing; D012275:Oryza; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
D012987:Soil; D002244:Carbon