Iris Chardon

Iris Chardon

Research assistant


Droevendaalsesteeg 10
6708 PB Wageningen

+31 (0) 317 47 34 00

The Netherlands



Chemistry is all around us! With my background in chemistry I assist in ecological research wherever I can.


Since the end of 2011, Iris Chardon (1987) works as a research assistant within the Microbial Ecology department of the Netherlands Institute of Ecology.

One of her main drivers is developing and/or optimising analytical methods, gaining and transferring knowledge, and thereby contributing to the development of others. Besides that, she is involved in research projects.

Iris is specialized in chemical analyses of soil, sediment, plant and headspace samples. She is responsible for three different gas chromatographs for measuring greenhouse gases, a laser diffraction analyser and a TOC analyser. Next to that she gives advice to (PhD-) students and (postdoctoral) researchers about nutrient or enzyme analyses, and instructs them for performing extractions or destructions. She analyses the extracts with ICP-OES, LC-MSMS, an AutoAnalyser or an Element Analyser.

From 2019 till 2023 she was involved as a research assistant within the TTW project ‘SmartResidue’, together with Paul Bodelier, Stijn van den Bergh, Gerard Korthals and Wietse de Boer. The project aimed to lower the greenhouse gas emission by turning agricultural soils into sinks of methane after application of bio-based residues. The mechanisms of this residue stimulated methane uptake have been investigated. Iris arranged the purchase of a laser diffraction analyser via a public tender, made the analyser operational, and developed methods to measure soil aggregate stability and particle size distribution with laser diffraction. Next to that, she performed many GC analyses, field screenings, DNA isolations, qPCR assays, nutrient analyses, PLFA extractions and much more.

Feel free to visit her LinkedIn page for more information:

2021 - fieldwork in Zurich
Femke van Beersum
greenhouse gas sampling in Zurich, Switzerland (2021)
2022 - explaining GC to King Willem-Alexander
Milette Raats
Explaining GC-measurement to King Willem-Alexander (2022)



Peer-reviewed publicaties

  • Soil Biology and Biochemistry

    Soil aggregate stability governs field greenhouse gas fluxes in agricultural soils

    Stijn van den Bergh, Iris Chardon, Marcio Fernandes Alves Leite, Gerard Korthals, Jochen Mayer, Mathias Cougnon, Dirk Reheul, Wietse de Boer, Paul Bodelier
    Agriculture is responsible for 30–50% of the yearly CO2, CH4, and N2O emissions. Soils have an important role in the production and consumption of these greenhouse gases (GHGs), with soil aggregates and the inhabiting microbes proposed to function as biogeochemical reactors, processing these gases. Here we studied, for the first time, the relationship between GHG fluxes and aggregate stability as determined via laser diffraction analysis (LDA) of agricultural soils, as well as the effect of sustainable agricultural management strategies thereon. Using the static chamber method, all soils were found to be sinks for CH4 and sources for CO2 and N2O. The application of organic amendments did not have a conclusive effect on soil GHG fluxes, but tilled soils emitted more CO2. LDA was a useful and improved method for assessing soil aggregate stability, as it allows for the determination of multiple classes of aggregates and their structural composition, thereby overcoming limitations of traditional wet sieving. Organic matter content was the main steering factor of aggregate stability. The presence of persistent stable aggregates and the disintegration coefficient of stable aggregates were improved in organic-amended and no-tilled soils. Predictive modelling showed that, especially in these soils, aggregate stability was a governing factor of GHG fluxes. Higher soil CH4 uptake rates were associated with higher aggregate stability, while CO2 and N2O emissions increased with higher aggregate stability. Altogether, it was shown that sustainable agricultural management strategies can be used to steer the soil's aggregate stability and, both consequently and outright, the soil GHG fluxes, thereby creating a potential to contribute to the mitigation of agricultural GHG emissions.
  • Waste Management

    The intrinsic methane mitigation potential and associated microbes add product value to compost

    Stijn van den Bergh, Iris Chardon, Marion Meima-Franke, Ohana Costa, Gerard Korthals, Wietse de Boer, Paul Bodelier
    Conventional agricultural activity reduces the uptake of the potent greenhouse gas methane by agricultural soils. However, the recently observed improved methane uptake capacity of agricultural soils after compost application is promising but needs mechanistic understanding. In this study, the methane uptake potential and microbiomes involved in methane cycling were assessed in green compost and household-compost with and without pre-digestion. In bottle incubations of different composts with both high and near-atmospheric methane concentrations (∼10.000 & ∼10 ppmv, respectively), green compost showed the highest potential methane uptake rates (up to 305.19 ± 94.43 nmol h−1 g dw compost−1 and 25.19 ± 6.75 pmol h−1 g dw compost−1, respectively). 16S, pmoA and mcrA amplicon sequencing revealed that its methanotrophic and methanogenic communities were dominated by type Ib methanotrophs, and more specifically by Methylocaldum szegediense and other Methylocaldum species, and Methanosarcina species, respectively. Ordination analyses showed that the abundance of type Ib methanotrophic bacteria was the main steering factor of the intrinsic methane uptake rates of composts, whilst the ammonium content was the main limiting factor, being most apparent in household composts. These results emphasize the potential of compost to contribute to methane mitigation, providing added value to compost as a product for industrial, commercial, governmental and public interests relevant to waste management. Compost could serve as a vector for the introduction of active methanotrophic bacteria in agricultural soils, potentially improving the methane uptake potential of agricultural soils and contributing to global methane mitigation, which should be the focus of future research.

Projecten & samenwerkingen


  • SmartResidue

    Project 2019–2023
    This project will investigate residue-stimulated atmospheric methane oxidation, and aims to elucidate its occurrence in field conditions, responsible microorganisms, underlying mechanisms and controlling factors.
    Sampling compost
  • Clever Cover cropping. Synergistic Mixtures for Sustainable Soils

    Project 2015–2020
    Since recently, Dutch farmers are required to grow cover crops in mixtures of at least two plant species.
    In the Clever Cropping Project we investigated whether mixtures of cover crops have beneficial effects on soil microbiology and associated functions.
    In long-term field experiments and laboratory incubations, we assessed emissions of greenhouse gasses and the diversity, abundance, and activity of microbial groups involved in environmentally relevant processes.
    While in laboratory incubations we could clearly find increased beneficial microbial functioning associated with mixtures of cover crop residues, we could not observe this in a 5-year field experiment.
    Overall, the use of cover crop mixtures did not have significant beneficial effects on soil microbial functioning but also no negative effects on for example greenhouse gas emissions.
    Gas flux measurements in Cover crops