title: In situ dynamics and spatial heterogeneity of soil bacterial communities under different crop residue management.
abstract: The effect of the location of wheat residues (soil surface vs. incorporated in soil) on their decomposition and on soil bacterial communities was investigated by the means of a field experiment. Bacterial-automated ribosomal intergenic spacer analysis of DNA extracts from residues, detritusphere (soil adjacent to residues), and bulk soil evidenced that residues constitute the zone of maximal changes in bacterial composition. However, the location of the residues influenced greatly their decomposition and the dynamics of the colonizing bacterial communities. Sequencing of 16S rRNA gene in DNA extracts from the residues at the early, middle, and late stages of degradation confirmed the difference of composition of the bacterial community according to the location. Bacteria belonging to the γ-subgroup of proteobacteria were stimulated when residues were incorporated whereas the α-subgroup was stimulated when residues were left at the soil surface. Moreover, Actinobacteria were more represented when residues were left at the soil surface. According to the ecological attributes of the populations identified, our results suggested that climatic fluctuations at the soil surface select populations harboring enhanced catabolic and/or survival capacities whereas residues characteristics likely constitute the main determinant of the composition of the bacterial community colonizing incorporated residues.
authors.affiliation: UMR Microbiologie du Sol et de l'Environnement, INRA/Université de Bourgogne CMSE, BP 86510, 17 rue de Sully, 21065 Dijon Cedex, France.
authors.forename: Noémie
authors.initials: N
authors.lastname: Pascault
authors.forename: Bernard
authors.initials: B
authors.lastname: Nicolardot
authors.forename: Fabiola
authors.initials: F
authors.lastname: Bastian
authors.forename: Pascal
authors.initials: P
authors.lastname: Thiébeau
authors.forename: Lionel
authors.initials: L
authors.lastname: Ranjard
authors.forename: Pierre-Alain
authors.initials: PA
authors.lastname: Maron
mesh_terms: D000383:Agriculture / Q000379:methods*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D001673:Biodegradation, Environmental; D018533:Biomass; D018556:Crops, Agricultural / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D015723:Gene Library; D059013:Microbial Consortia; D009584:Nitrogen / Q000032:analysis; D025341:Principal Component Analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D014908:Triticum / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S; D012987:Soil; D009584:Nitrogen