Résumé

The access and recycling of the base cations are essential processes for the long-lasting functioning of forest ecosystems. While the role of soil bacterial communities has been demonstrated in mineral weathering and tree nutrition, our understanding of the link between the availability of base cations and the functioning of these communities remains limited. To fill this gap, we developed a microcosm approach to investigate how an increase in key base cations (potassium or magnesium) impacted the taxonomic and functional structures of the bacterial communities. During a 2-month period after fertilization with available potassium or magnesium, soil properties, global functions (metabolic potentials and respiration) as well as mineral weathering bioassays and 16S rRNA amplicon pyrosequencing were monitored. Our analyses showed no or small variations in the taxonomic structure, total densities and global functions between the treatments. In contrast, a decrease in the frequency and effectiveness of mineral weathering bacteria was observed in the fertilized treatments. Notably, quantitative PCR targeting specific genera known for their mineral weathering ability (i.e., Burkholderia and Collimonas) confirmed this decrease. These new results suggest that K and Mg cation availability drives the distribution of the mineral weathering bacterial communities in forest soil.

Auteurs, date et publication :

Auteurs O. Nicolitch , M. Feucherolles , J.-L. Churin , L. Fauchery , M.-P. Turpault , S. Uroz

Publication : Scientific Reports

Date : 2019

Volume : 9

Issue : 1

Pages : 14403

Catégorie(s)

#FORET Montiers #INRAE

Résumé

Microplastic (MP) input into agroecosystems is of particular concern as their sources are diverse (mulching films, biosolid application, wastewater irrigation, flooding, atmospheric input, road runoff). Compost application, which is needed to sustain soil ecosystem services in the context of a circular economy, may be a source of microplastics. The aim of this study was to evaluate how different composts derived from urban wastes impact the nature and quantity of coarse (2–5 mm) microplastics (CMP) in soils, using a long-term field experiment in France. Composts resulting from different levels of urban waste sorting were investigated. Our approach included the isolation of microplastics from composts and amended soils followed by their characterization using pyrolysis GC/MS spectrometry. We found that coarse microplastic concentrations varied from 26.9 to 417 kg per hectare depending on the compost type, after 22 years of bi-annual application. These values may be higher than for conventional agricultural practices, as application rate was twice as high as for normal practices. Composts made from municipal solid waste were by far the organic amendments leading to the highest quantity of plastic particles in soils, emphasizing the urgent need for limiting plastic use in packaging and for improving household biowaste sorting. Our results strongly suggest that standards regulating organic matter amendment application should take microplastics into account in order to prevent contamination of (agricultural) soils. Moreover, although no impacts on the soil bio-physico-chemical parameters has been noted so far. However, given the huge microplastic inputs, there is an urgent need to better evaluate their effect on soil functioning.

Auteurs, date et publication :

Auteurs Gabin Colombini , Cornelia Rumpel , Sabine Houot , Philippe Biron , Marie-France Dignac

Publication : Environmental Pollution

Date : 2025

Volume : 315

Pages : 120369

Catégorie(s)

#ANR-Citation #INRAE #PRO #PRO QualiAgro

Résumé

The establishment of the range of soil biodiversity found within European soils is needed to guide EU policy development regarding the protection of soil. Such a base-line should be collated from a wide-ranging sampling campaign to ensure that soil biodiversity from the majority of soil types, land-use or management systems, and European climatic (bio-geographical zones) were included. This paper reports the design and testing of a method to achieve the large scale sampling associated with the establishment of such a baseline, carried out within the remit of the EcoFINDERS project, and outlines points to consider when such a task is undertaken. Applying a GIS spatial selection process, a sampling campaign was undertaken by 13 EcoFINDERS partners across 11 countries providing data on the range of indicators of biodiversity and ecosystem functions including; micro and meso fauna biodiversity, extracellular enzyme activity, PLFA and community level physiological profiling (MicroResp™ and Biolog™). Physical, chemical and bio-geographical parameters of the 81 sites sampled were used to determine whether the model predicted a wide enough range of sites to allow assessment of the biodiversity indicators tested. Discrimination between the major bio-geographical zones of Atlantic and Continental was possible for all land-use types. Boreal and Alpine zones only allowed discrimination in the most common land-use type for that area e.g. forestry and grassland sites, respectively, while the Mediterranean zone did not have enough sites sampled to draw conclusions across all land-use types. The method used allowed the inclusion of a range of land-uses in both the model prediction stage and the final sites sampled. The establishment of the range of soil biodiversity across Europe is possible, though a larger targeted campaign is recommended. The techniques applied within the EcoFINDERS sampling would be applicable to a larger campaign.

Auteurs, date et publication :

Auteurs D. Stone , P. Blomkvist , N. Bohse Hendriksen , M. Bonkowski , H. Bracht Jørgensen , F. Carvalho , M. B. Dunbar , C. Gardi , S. Geisen , R. Griffiths , A. S. Hug , J. Jensen , H. Laudon , S. Mendes , P. V. Morais , A. Orgiazzi , P. Plassart , J. Römbke , M. Rutgers , R. M. Schmelz

Publication : Applied Soil Ecology

Date : 2016

Volume : 97

Pages : 3-11

Catégorie(s)

#Genosol #INRAE

Résumé

Most agronomic crop models use a reservoir tipping-bucket approach to model the water budget in the soil. Soil available water capacity (AWC) is the main soil property considered in this approach. Because AWC is difficult to measure, uncertainty in AWC may be high. We developed a method using a specific kriging technique to determine the effects of uncertainty in AWC on crop model predictions. The AqYield crop model was used as an example to assess the effects of uncertainty in AWC on two agronomic output variables (grain yield and drainage). The factors considered were the climatic region, crop type and soil depth. We assessed the results using the coefficient of variation (CV) and sets of critical values for which CV exceeded 5, 10 and 15%. The experiment provided insight into the criticality of AWC uncertainty over a wide range of agropedoclimatic situations according to crop, model and output of interest. The method revealed the greater effect of AWC uncertainty on both outputs for the spring crop than for the winter crop and identified cases where AWC uncertainty was critical. There was a stronger effect of AWC uncertainty on yield for shallow soil and climatic water deficit conditions. For each situation, the AWC uncertainty levels were determined above or below which the impact becomes significant on a given output because the sensitivity was very dependent on climate–crop–soil combinations. It was also observed that uncertainty in AWC had little effect in AqYield for a wide range of situations. The method developed uses a small number of model simulations to produce accurate results to better understand the impact of this major soil input data according to the target model and specific objectives. It could help to determine the level of accuracy needed in AWC measurement, depending on the objectives. Highlights The method quantifies the effects of AWC uncertainty on crop models with a tipping-bucket approach. This method can assess the impact of uncertainty with only a few runs using a kriging approach. The method identifies critical situations for a wide range of agropedoclimatic conditions. Critical region graphs give critical thresholds for accuracy needed in AWC.

Auteurs, date et publication :

Auteurs Julie Constantin , Victor Picheny , Lina H. Nassar , Jacques-Eric Bergez

Publication : European Journal of Soil Science

Date : 2025

Volume : 71

Issue : 3

Pages : 369-381

Catégorie(s)

#INRAE #Record

Résumé

Farming systems are complex and have several dimensions that interact in a dynamic and continuous manner depending on farmers' management strategies. This complexity peaks in Indian semi-arid regions, where small farms encounter a highly competitive environment for markets and resources, especially unreliable access to water from rainfall and irrigation. NAMASTE, a dynamic computer model for water management at the farm level, was developed to reproduce interactions between decisions (investment and technical) and processes (resource management and biophysical) under scenarios of climate-change, socio-economic and water-management policies. The most relevant and novel aspects are i) system-based representation of farming systems, ii) description of dynamic processes via management flexibility and adaptation, iii) representation of farmers' decision-making processes at multiple temporal and spatial scales, iv) management of shared resources. NAMASTE's ability to simulate farmers' adaptive decision-making processes is illustrated by simulating a virtual Indian village composed of two virtual farms with access to groundwater.

Auteurs, date et publication :

Auteurs Marion Robert , Alban Thomas , Muddu Sekhar , Hélène Raynal , Éric Casellas , Pierre Casel , Patrick Chabrier , Alexandre Joannon , Jacques-Éric Bergez

Publication : Environmental Modelling & Software

Date : 2018

Volume : 100

Pages : 123-135

Catégorie(s)

#INRAE #Record

Auteurs, date et publication :

Auteurs R.-C. Costa Pinheiro , De Deus Junior J-C , Nouvellon Y , Camargo Campoe O , Stape J-L , Lanzi A-L , Guerrini I-A , Jourdan C , J.-P. Laclau

Publication : Forest Ecology and Management

Date : 2025

Volume : 366

Pages : 143-152

Catégorie(s)

#CIRAD #FORET Itatinga #INRAE

Résumé

Questions: Does vegetation structure display any stability over the grazing season and in two successive years, and is there any correlation between the stability of these spatial patterns and local sward composition? Location: An upland grassland in the French Massif Central. Method: The mosaic of short and tall vegetation stands considered as grazed and ungrazed patches respectively is modeled as the realization of a Boolean process. This method does not require any arbitrarily set sward-height thresholds to discriminate between grazed and ungrazed areas, or the use of additional variables such as defoliation indexes. The model was validated by comparing empirical and simulated sward-height distributions and semi-variograms. Results: The model discriminated between grazed and ungrazed patches at both a fine (1 m2) and a larger (500 m2) scale. Selective grazing on legumes and forbs and avoidance of reproductive grass could partly explain the stability of fine-scale grazing patterns in lightly grazed plots. In these plots, the model revealed an inter-annual stability of large-scale grazing patterns at the time peak biomass occurred. At the end of the grazing season, lightly grazed plots showed fluctuating patch boundaries while heavily grazed plots showed a certain degree of patch stability. Conclusion: The model presented here reveals that selective grazing at the bite scale could lead to the creation of relatively stable patches within the pasture. Locally maintaining short cover heights would result in divergent within-plot vegetation dynamics, and thus favor the functional diversity of vegetation.

Auteurs, date et publication :

Auteurs Nicolas Rossignol , Joël Chadoeuf , Pascal Carrère , Bertrand Dumont

Publication : Applied Vegetation Science

Date : 2025

Volume : 14

Issue : 2

Pages : 189-199

Catégorie(s)

#ACBB #ACBB Theix #INRAE

Résumé

Now that evasion of carbon dioxide (CO2) from inland waters is accounted for in global carbon models, it is crucial to quantify how these fluxes have changed in the past and forecast how they may alter in the future in response to local and global change. Here we developed a sediment proxy for the concentration of summer surface dissolved CO2 concentration and used it to reconstruct changes over the past 150 years for three large lakes that have been affected by climate warming, changes in nutrient load, and detrital terrigenous supplies. Initially CO2 neutral to the atmosphere, all three lakes subsequently fluctuated between near equilibrium and supersaturation. Although catchment inputs have supplied CO2 to the lakes, internal processes and reallocation have ultimately regulated decadal changes in lake surface CO2 concentration. Nutrient concentration has been the dominant driver of CO2 variability for a century although the reproducible, nonmonotonic relationship of CO2 to nutrient concentration suggests an interplay between metabolic and chemical processes. Yet for two of these lakes, climatic control of CO2 concentrations has been important over the last 30 years, promoting higher surface CO2 concentrations, likely by decreasing hypolimnetic carbon storage. This new approach offers the unique opportunity to scale, a posteriori, the long-term impact of human activities on lake CO2.

Auteurs, date et publication :

Auteurs Marie-Elodie Perga , Stephen C. Maberly , Jean-Philippe Jenny , Benjamin Alric , Cécile Pignol , Emmanuel Naffrechoux

Publication : Global Biogeochemical Cycles

Date : 2025

Volume : 30

Issue : 2

Pages : 93-104

Catégorie(s)

#INRAE #OLA

Auteurs, date et publication :

Auteurs Thierry Morvan , Charlotte Lemoine , Florian Gaillard , Gaelle Hamelin , Béatrice Trinkler , Laurence Carteaux , Patrice Petitjean , Anne Jaffrezic

Publication : Data in Brief

Date : 2025

Volume : 32

Pages : 106029

Catégorie(s)

#ANR-Citation #INRAE #PRO #PRO EFELE

Résumé

This study aimed to describe the influence of different electrofishing engine configurations on electric field dispersion in water. Several experiments with original results are included. The aims were to (i) assess the equivalent electrode resistances and the output voltage at the anode, (ii) assess the influence of electrode misuse on the dispersal of the electric field in water, (iii) assess the influence of the duty cycle and the frequency on the radius of attraction around the anode, and (iv) set the voltage and the duty cycle based on information from models for backpack and bankside electrofishing engines. A synthesis of equivalent electrode resistances from different studies was created. Using an oxidised anode induced a decrease in the radius of attraction. Frequency had no influence on the radius of attraction, in contrast to the duty cycle. Models including the voltage and the duty cycle were created to enable the configuration of electrofishing engines.

Auteurs, date et publication :

Auteurs Gaétan Pottier , Frédéric Marchand , Laurent Beaulaton

Publication : Environmental Monitoring and Assessment

Date : 2019

Volume : 192

Issue : 1

Pages : 22

Catégorie(s)

#ANR-Citation #INRAE #PEARL