Soil Biology and Biochemistry, Nov, 2013, Vol.66, p.69(9)
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.soilbio.2013.07.001 Byline: Aurore Kaisermann, Adelaide Roguet, Naoise Nunan, Pierre-Alain Maron, Nicholas Ostle, Jean-Christophe Lata Abstract: Soil microorganisms are responsible for organic matter decomposition processes that regulate soil carbon storage and mineralisation to CO.sub.2. Climate change is predicted to increase the frequency of drought events, with uncertain consequences for soil microbial communities. In this study we tested the hypothesis that agricultural management used to enhance soil carbon stocks would increase the stability of microbial community structure and activity in response to water-stress. Soil was sampled from a long-term field trial with three soil carbon management systems and was used in a laboratory study of the effect of a dry-wet cycle on organic C mineralisation and microbial community structure. After a drying-rewetting event, soil microcosms were maintained wet and microbial community structure and abundance as well as microbial respiration were measured for four weeks. The results showed that the NO-TILL management system, with the highest soil organic matter content and respiration rate, had a distinct bacterial community structure relative to the conventional and the TILL without fertiliser systems. In all management systems, the rewetting event clearly modified microbial community structure and activity. Both returned to their pre-drought state after 28 days. However, the magnitude of variation of C mineralisation was lower (i.e. the resistance to stress was higher) in the NO-TILL system. The genetic structure of the NO-TILL bacterial communities was most modified by water-stress and exhibited a slower recovery rate. This suggests that land use management can increase microbial functional resistance to drought stress via the establishment of bacterial communities with particular metabolic capacities. Nevertheless, the resilience rates of C mineralisation were similar among management regimes, suggesting that similar mechanisms occur, maybe due to a common soil microbial community legacy. Author Affiliation: (a) Laboratoire Bioemco, CNRS/UPMC, 46 rue d'Ulm, 75230 Paris Cedex 5, France (b) Laboratoire Bioemco, CNRS/UPMC, Batiment EGER Campus AgroParisTech, F-78850 Thiverval Grignon, France (c) UMR 1347 Agroecology INRA - AgroSup Dijon - University of Burgundy, 17, rue Sully, B.V. 86510, 21065 Dijon Cedex, France (d) Platform GenoSol, UMR Agroecology INRA - AgroSup Dijon - University of Burgundy, 17, rue Sully, B.V. 86510, 21065 Dijon Cedex, France (e) Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, UK Article History: Received 14 May 2013; Accepted 1 July 2013
Global Temperature Changes ; No-tillage ; Soil Carbon
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