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Weixin Cheng - One of the best experts on this subject based on the ideXlab platform.
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rhizosphere Priming Effect its functional relationships with microbial turnover evapotranspiration and c n budgets
Soil Biology & Biochemistry, 2009Co-Authors: Weixin ChengAbstract:Understanding soil organic matter (SOM) decomposition and its interaction with rhizosphere processes is a crucial topic in soil biology and ecology. Using a natural 13C tracer method to separately measure SOM-derived CO2 from root-derived CO2, this study aims to connect the level of rhizosphere-dependent SOM decomposition with the C and N balance of the whole plant–soil system, and to mechanistically link the rhizosphere Priming Effect to soil microbial turnover and evapotranspiration. Results indicated that the magnitude of the rhizosphere Priming Effect on SOM decomposition varied widely, from zero to more than 380% of the unplanted control, and was largely influenced by plant species and phenology. Balancing the extra soil C loss from the strong rhizosphere Priming Effect in the planted treatments with C inputs from rhizodeposits and root biomass, the whole plant–soil system remained with a net carbon gain at the end of the experiment. The increased soil microbial biomass turnover rate and the enhanced evapotranspiration rate in the planted treatments had clear positive relationships with the level of the rhizosphere Priming Effect. The rhizosphere enhancement of soil carbon mineralization in the planted treatments did not result in a proportional increase in net N mineralization, suggesting a possible de-coupling of C cycling with N cycling in the rhizosphere.
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Rhizosphere Priming Effect: Its functional relationships with microbial turnover, evapotranspiration, and C–N budgets
Soil Biology and Biochemistry, 2009Co-Authors: Weixin ChengAbstract:Understanding soil organic matter (SOM) decomposition and its interaction with rhizosphere processes is a crucial topic in soil biology and ecology. Using a natural 13C tracer method to separately measure SOM-derived CO2 from root-derived CO2, this study aims to connect the level of rhizosphere-dependent SOM decomposition with the C and N balance of the whole plant–soil system, and to mechanistically link the rhizosphere Priming Effect to soil microbial turnover and evapotranspiration. Results indicated that the magnitude of the rhizosphere Priming Effect on SOM decomposition varied widely, from zero to more than 380% of the unplanted control, and was largely influenced by plant species and phenology. Balancing the extra soil C loss from the strong rhizosphere Priming Effect in the planted treatments with C inputs from rhizodeposits and root biomass, the whole plant–soil system remained with a net carbon gain at the end of the experiment. The increased soil microbial biomass turnover rate and the enhanced evapotranspiration rate in the planted treatments had clear positive relationships with the level of the rhizosphere Priming Effect. The rhizosphere enhancement of soil carbon mineralization in the planted treatments did not result in a proportional increase in net N mineralization, suggesting a possible de-coupling of C cycling with N cycling in the rhizosphere.
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Rhizosphere Priming Effect of Populus fremontii obscures the temperature sensitivity of soil organic carbon respiration
Soil Biology and Biochemistry, 2007Co-Authors: Nicholas E. Bader, Weixin ChengAbstract:Abstract C efflux from soils is a large component of the global C exchange between the biosphere and the atmosphere. However, our understanding of soil C efflux is complicated by the “rhizosphere Priming Effect,” in which the presence of live roots may accelerate or suppress the decomposition of soil organic C. Due to technical obstacles, the rhizosphere Priming Effect is under-studied, and we know little about rhizosphere Priming in tree species. We measured the rates of soil-derived C mineralization in root-free soil and in soil planted with cottonwood (Populus fremontii) trees. Live cottonwood roots greatly accelerated (a rhizosphere Priming Effect) or suppressed (a negative rhizosphere Priming Effect) the mineralization of soil organic C, depending upon the time of the year. At its maximum, soil organic C was mineralized nine times faster in the presence of cottonwood roots than in the unplanted controls. Over the course of the experiment, approximately twice as much soil organic C was mineralized in pots planted with cottonwoods compared to unplanted control pots. Soil organic C mineralization rates in the unplanted controls were temperature-sensitive. In contrast, soil organic C mineralization in the cottonwood rhizosphere was unresponsive to seasonal temperature changes, due to the strength of the rhizosphere Priming Effect. The rhizosphere Priming Effect is of key importance to our understanding of soil C mineralization, because it means that the total soil respiration is not a simple additive function of soil-derived and plant-derived respiration.
Claire Chenu - One of the best experts on this subject based on the ideXlab platform.
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Is Priming Effect a significant process for long-term SOC dynamics? Analysis of a 52-years old experiment Quelle est l'importance du "Priming Effect" à long terme ? Apport d'une expérimentation au champ de 52 ans
2016Co-Authors: Rémi Cardinael, Thomas Eglin, Cathy Neill, Bertrand Guenet, Sabine Houot, Claire ChenuAbstract:13èmes Journées d’étude des sols 2016 90 S7 Présentations poster Quelle est l’importance du « Priming Effect » à long terme ? Apport d’une expérimentation au champ de 52 ans Rémi Cardinael, Thomas Eglin, Bertrand Guenet, Cathy Neil, Sabine Houot, Claire Chenu UMR Ecosys, INRA AgroParisTech Grignon; ADEME, Angers; LSCE, CNRS, Saclay Introduction. Des expérimentations en laboratoire sur temps court ont montré que la vitesse de minéralisation des matières organiques du sol pouvait être augmentée par l’apport de matières organiques fraiches, une sur-minéralisation que l’on dénomme « Priming Effect ». Ce processus pourrait affecter la dynamique du C à des échelles globales, mais son importance n’a pas encore été évaluée à des échelles de temps pluriannuelles à décennales. Matériels et méthodes. Dans cette étude, nous avons analysé l’évolution des teneurs et stocks de carbone organique du sol d’une expérimentation de jachère nue de longue durée (52 ans), située à Grignon (Yvelines, France). Les sols ont été gardés nus depuis le début de l’essai par désherbage manuel ou chimique et les parcelles ont reçu, soit aucun apport organique depuis 52 ans, soit un apport annuel de paille fraîche ou encore un apport annuel de paille compostée. Nous avons fait l’hypothèse que l’apport de paille fraiche s’accompagnerait d’un Priming Effect contrairement à l’apport de paille compostée et que les stocks de C organique du sol devraient donc se différencier au cours du temps entre les différentes parcelles. Des échantillons d’archive ont permis d’établir la cinétique d’évolution du carbone organique de l’horizon de surface (0-20 cm) des sols. Résultats Nous n’avons observé aucune différence significative entre les stocks de C organique des sols, que la paille ait été apportée fraîche ou compostée, ce qui suggère une absence de Priming Effect à long terme. Pour aller plus loin, nous avons évalué si les taux de minéralisation de la matière organique du sol différaient entre les parcelles avec et sans entrée de matière organique fraîche au sol, en utilisant des modèles simples de la dynamique du COS basés sur le formalisme Hénin-Dupuis. En utilisant un modèle à 3 compartiments de carbone nous avons trouvé que les vitesses de minéralisation du carbone sont 2 à 4 fois plus lentes dans apport de matière organique fraîche qu’avec. Ceci suggère un Priming Effect important. Cependant, en utilisant un modèle à 4 compartiments de carbone, une cinétique de premier ordre avec les mêmes paramètres décrit bien l’évolution des teneurs en carbone dans toutes les parcelles de l’essai. Conclusion Nos résultats ne permettent pas de conclure à l’absence d’un effet du Priming Effect sur les stocks de carbone organique du sol à l'échelle de temps décennales, mais suggèrent que ce processus n’est pas essentiel, ni peut être pertinent pour expliquer la dynamique du carbone organique des sols à long terme.
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Is Priming Effect a significant process for long-term SOC dynamics? Analysis of a 52-years old experiment
Biogeochemistry, 2015Co-Authors: Rémi Cardinael, Thomas Eglin, Cathy Neill, Bertrand Guenet, Sabine Houot, Claire ChenuAbstract:Short time scale (~days to year) soil incubation experiments have evidenced that mineralisation rate of soil organic carbon could be increased by higher fresh organic matter (FOM) inputs. This process could affect global soil C stocks but its importance has yet to be assessed at decennial or centennial time-scales. In this study, we analysed soil organic carbon (SOC) data from a 52-years old bare-fallow experiment in Grignon (France) where plots received no organic matter, or only fresh straw or composted straw. Treatments receiving fresh or composted straw showed no significant difference in SOC stocks dynamics over the 52 years, suggesting no long-term impact of Priming Effect. To go further, we evaluated whether soil organic matter (SOM) mineralisation rates differed between plots with no input and plots with FOM inputs, using simple models of SOC dynamics based on the Hénin-Dupuis formalism. Using a model with three SOC pools, we showed that estimated mineralisation rates were 3–4 times slower for the plots with no input, suggesting an important role of Priming Effect. However, a 4-pools model with first order kinetics could satisfactorily fit all the data using a same set of parameters. Our results did not assess the absence of Priming Effect on SOC stocks dynamics at decennial timescale, but suggest that Priming Effect is not necessarily a relevant process to explain long-term SOC dynamics. It would be worthwhile to test our modelling approach on other long-term datasets, in particular from more nitrogen-limited experiments and using other data giving complementary information on mineralisation rates, such as 14C.
Rémi Cardinael - One of the best experts on this subject based on the ideXlab platform.
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Is Priming Effect a significant process for long-term SOC dynamics? Analysis of a 52-years old experiment Quelle est l'importance du "Priming Effect" à long terme ? Apport d'une expérimentation au champ de 52 ans
2016Co-Authors: Rémi Cardinael, Thomas Eglin, Cathy Neill, Bertrand Guenet, Sabine Houot, Claire ChenuAbstract:13èmes Journées d’étude des sols 2016 90 S7 Présentations poster Quelle est l’importance du « Priming Effect » à long terme ? Apport d’une expérimentation au champ de 52 ans Rémi Cardinael, Thomas Eglin, Bertrand Guenet, Cathy Neil, Sabine Houot, Claire Chenu UMR Ecosys, INRA AgroParisTech Grignon; ADEME, Angers; LSCE, CNRS, Saclay Introduction. Des expérimentations en laboratoire sur temps court ont montré que la vitesse de minéralisation des matières organiques du sol pouvait être augmentée par l’apport de matières organiques fraiches, une sur-minéralisation que l’on dénomme « Priming Effect ». Ce processus pourrait affecter la dynamique du C à des échelles globales, mais son importance n’a pas encore été évaluée à des échelles de temps pluriannuelles à décennales. Matériels et méthodes. Dans cette étude, nous avons analysé l’évolution des teneurs et stocks de carbone organique du sol d’une expérimentation de jachère nue de longue durée (52 ans), située à Grignon (Yvelines, France). Les sols ont été gardés nus depuis le début de l’essai par désherbage manuel ou chimique et les parcelles ont reçu, soit aucun apport organique depuis 52 ans, soit un apport annuel de paille fraîche ou encore un apport annuel de paille compostée. Nous avons fait l’hypothèse que l’apport de paille fraiche s’accompagnerait d’un Priming Effect contrairement à l’apport de paille compostée et que les stocks de C organique du sol devraient donc se différencier au cours du temps entre les différentes parcelles. Des échantillons d’archive ont permis d’établir la cinétique d’évolution du carbone organique de l’horizon de surface (0-20 cm) des sols. Résultats Nous n’avons observé aucune différence significative entre les stocks de C organique des sols, que la paille ait été apportée fraîche ou compostée, ce qui suggère une absence de Priming Effect à long terme. Pour aller plus loin, nous avons évalué si les taux de minéralisation de la matière organique du sol différaient entre les parcelles avec et sans entrée de matière organique fraîche au sol, en utilisant des modèles simples de la dynamique du COS basés sur le formalisme Hénin-Dupuis. En utilisant un modèle à 3 compartiments de carbone nous avons trouvé que les vitesses de minéralisation du carbone sont 2 à 4 fois plus lentes dans apport de matière organique fraîche qu’avec. Ceci suggère un Priming Effect important. Cependant, en utilisant un modèle à 4 compartiments de carbone, une cinétique de premier ordre avec les mêmes paramètres décrit bien l’évolution des teneurs en carbone dans toutes les parcelles de l’essai. Conclusion Nos résultats ne permettent pas de conclure à l’absence d’un effet du Priming Effect sur les stocks de carbone organique du sol à l'échelle de temps décennales, mais suggèrent que ce processus n’est pas essentiel, ni peut être pertinent pour expliquer la dynamique du carbone organique des sols à long terme.
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Is Priming Effect a significant process for long-term SOC dynamics? Analysis of a 52-years old experiment
Biogeochemistry, 2015Co-Authors: Rémi Cardinael, Thomas Eglin, Cathy Neill, Bertrand Guenet, Sabine Houot, Claire ChenuAbstract:Short time scale (~days to year) soil incubation experiments have evidenced that mineralisation rate of soil organic carbon could be increased by higher fresh organic matter (FOM) inputs. This process could affect global soil C stocks but its importance has yet to be assessed at decennial or centennial time-scales. In this study, we analysed soil organic carbon (SOC) data from a 52-years old bare-fallow experiment in Grignon (France) where plots received no organic matter, or only fresh straw or composted straw. Treatments receiving fresh or composted straw showed no significant difference in SOC stocks dynamics over the 52 years, suggesting no long-term impact of Priming Effect. To go further, we evaluated whether soil organic matter (SOM) mineralisation rates differed between plots with no input and plots with FOM inputs, using simple models of SOC dynamics based on the Hénin-Dupuis formalism. Using a model with three SOC pools, we showed that estimated mineralisation rates were 3–4 times slower for the plots with no input, suggesting an important role of Priming Effect. However, a 4-pools model with first order kinetics could satisfactorily fit all the data using a same set of parameters. Our results did not assess the absence of Priming Effect on SOC stocks dynamics at decennial timescale, but suggest that Priming Effect is not necessarily a relevant process to explain long-term SOC dynamics. It would be worthwhile to test our modelling approach on other long-term datasets, in particular from more nitrogen-limited experiments and using other data giving complementary information on mineralisation rates, such as 14C.
Stéphane Mounier - One of the best experts on this subject based on the ideXlab platform.
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Grassland-cropland rotation cycles in crop-livestock farming systems regulate Priming Effect potential in soils through modulation of microbial communities, composition of soil organic matter and abiotic soil properties
Agriculture Ecosystems and Environment, 2020Co-Authors: Marco Panettieri, Pierre-alain Maron, Lionel Ranjard, Julien Guigue, Nicolas Chemidlin Prévost-bouré, Mathieu Thévenot, Jean Lévêque, Cédric Le Guillou, Anne-lise Santoni, Stéphane MounierAbstract:Soils can act as a carbon sink, and the chemical and biological transformation of vegetal litter into soil organic matter (SOM) is widely influenced by land-use and other biogeochemical parameters. However, the increase of new carbon inputs to soil has the potential to trigger the mineralization of stabilized SOM, a process called Priming Effect. The objective of this manuscript is to investigate, at a landscape scale (5 km²), the factors influencing the susceptibility of SOM to Priming Effect. To achieve this objective, physical, chemical, and metagenomics analyses were conducted on 88 soil samples and successively combined with agronomical data and soil incubation for the quantification of carbon fluxes. Variance partitioning models highlighted that Priming Effect is controlled by complex interactions of biotic and abiotic factors, which include soil chemistry, quality of SOM, shape and abundance of microbial communities. Fluorescence properties of the dissolved organic matter has been found as a strong descriptor for Priming Effect. Depending on the time of crop rotation devoted to grassland, two different components leading to Priming Effect were identified. The introduction of grassland for 40–60% of the time of rotation achieved the lowest susceptibility to Priming Effect, and higher indexes of microbial diversity, whereas higher or lower proportions of time of the rotation devoted to grassland resulted in an increase of Priming Effect and a decrease of bacterial evenness.
Luc Abbadie - One of the best experts on this subject based on the ideXlab platform.
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Priming Effect: bridging the gap between terrestrial and aquatic ecology
Ecology, 2010Co-Authors: Bertrand Guenet, Michael Danger, Luc Abbadie, Gérard LacroixAbstract:Understanding how ecosystems store or release carbon is one of ecology's greatest challenges in the 21st century. Organic matter covers a large range of chemical structures and qualities, and it is classically represented by pools of different recalcitrance to degradation. The interaction Effects of these pools on carbon cycling are still poorly understood and are most often ignored in global-change models. Soil scientists have shown that inputs of labile organic matter frequently tend to increase, and often double, the mineralization of the more recalcitrant organic matter. The recent revival of interest for this phenomenon, named the Priming Effect, did not cross the frontiers of the disciplines. In particular, the Priming Effect phenomenon has been almost totally ignored by the scientific communities studying marine and continental aquatic ecosystems. Here we gather several arguments, experimental results, and field observations that strongly support the hypothesis that the Priming Effect is a general phenomenon that occurs in various terrestrial, freshwater, and marine ecosystems. For example, the increase in recalcitrant organic matter mineralization rate in the presence of labile organic matter ranged from 10% to 500% in six studies on organic matter degradation in aquatid ecosystems. Consequently, the recalcitrant organic matter mineralization rate may largely depend on labile organic matter availability, influencing the CO2 emissions of both aquatic and terrestrial ecosystems. We suggest that (1) recalcitrant organic matter may largely contribute to the CO2 emissions of aquatic ecosystems through the Priming Effect, and (2) Priming Effect intensity may be modified by global changes, interacting with eutrophication processes and atmospheric CO2 increases. Finally, we argue that the Priming Effect acts substantially in the carbon and nutrient cycles in all ecosystems. We outline exciting avenues for research, which could provide new insights on the responses of ecosystems to anthropogenic perturbations and their feedbacks to climatic changes.
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the Priming Effect of organic matter a question of microbial competition
Soil Biology & Biochemistry, 2003Co-Authors: Sebastien Fontaine, Andre Mariotti, Luc AbbadieAbstract:It is generally accepted that the low quality of soil carbon limits the amount of energy available for soil microorganisms, and in turn the rate of soil carbon mineralization. The Priming Effect, i.e. the increase in soil organic matter (SOM) decomposition rate after fresh organic matter input to soil, is often supposed to result from a global increase in microbial activity due to the higher availability of energy released from the decomposition of fresh organic matter. Work to date, however, suggests that supply of available energy induces no Effect on SOM mineralization. The mechanisms of the Priming Effect are much more complex than commonly believed. The objective of this review was to build a conceptual model of the Priming Effect based on the contradictory results available in the literature adopting the concept of nutritional competition. After fresh organic matter input to soils, many specialized microorganisms grow quickly and only decompose the fresh organic matter. We postulated that the Priming Effect results from the competition for energy and nutrient acquisition between the microorganisms specialized in the decomposition of fresh organic matter and those feeding on polymerised SOM.
