Scientific Conferences

 

At Andes, our approach to Carbon Dioxide Removal (CDR) is grounded in rigorous scientific research. In addition to publishing peer-reviewed papers, we regularly present our findings to the scientific community at international conferences and workshops. Below, you'll find a selection of recent presentations detailing the mechanisms, modeling, and field validation of our microbial weathering technology.

 

Microbially Accelerated Weathering: Leveraging Biology to Enhance Weathering in Alkaline Soils

4th Enhanced Rock Weathering Conference (ERW'26)
Guelph, Ontario, Canada · July 2026 · Oral presentation (O7)

In this presentation, Andes scientists presented an overview of Microbially Accelerated Weathering (MAW), a biologically driven pathway to carbon dioxide removal. One important aspect of MAW is that it is mechanistically distinct from conventional enhanced rock weathering: Rather than transporting crushed silicate rock into acidic soils, Andes applies, through a seed treatment, root-associated Bacillus sp. strains that accelerate the weathering of silicate minerals already present in alkaline agricultural soils. Another key aspect of MAW is its unique approach to measurement, reporting, and verification (MRV), which leverages changes in soil inorganic carbon as a conservative, cost-effective way to quantify carbon removal. This talk brought together evidence spanning laboratory studies, soil mesocosms, reactive transport modeling, and commercial field deployment.

Key Findings:

  • MAW is a distinct CDR pathway: Andes’ microbes grow with plant roots and accelerate weathering of pre-existing cation-bearing silicates in alkaline soils, with soil inorganic carbon (calcium carbonate equivalent) providing a direct, conservative basis for MRV rather than cation-proxy or feedstock mass-balance models.

  • In vitro studies help clarify the modes of action through which Andes’ microbes accelerate weathering. This research shows that microbes can regulate soil pH. By modulating the pH of soil microenvironments, microbes can increase silicate dissolution rates, releasing calcium and magnesium and later favoring carbonate formation. Biofilms forming directly on cation-bearing silicates likely play an important role in this process (Timmermann et al. 2025, Global Change Biology).

  • Mesocosm experiments confirm increased silicate weathering is coupled with carbonate formation. Andes’ microbial strain MP1 increased base cations and soil inorganic carbon in 60- to 90-day experiments. In these studies, sequential selective extractions were used to trace the cations from silicate dissolution (Lawrence et al., preprint on CDRXIV), and metagenomic/qPCR analyses confirmed that the microbes persist through the experiments (Yang et al. 2026, Global Change Biology).

  • Reactive transport modeling is being used to constrain and better understand the weathering system. Early model results based on mesocosm data suggest Andes’ microbial inoculant increases anorthite weathering by roughly sevenfold. The model indicates that accumulation of soil inorganic carbon is an effective proxy for weathering increases, and that formation of secondary minerals, including but not limited to carbonate, may sustain additional silicate weathering (Lawrence et al. 2026, in prep.).

  • Data from field deployment trials support the scalability of MAW. Across more than 300 midwestern soybean fields during the 2023–2024 seasons, application of the Andes’ MP1 microbe to soils with an initial pH ≥ 7.0 resulted in significant soil inorganic carbon accumulation, with minimal change in pH or base saturation compared with control soils.

 

Microbially Accelerated Weathering for CDR: Reactive Transport Modeling to Quantify Rates and Sinks

EGU General Assembly 2026 (EGU26)
Vienna, Austria · 3–8 May 2026 — Session SSS5.4 — Carbon sequestration in soils · Abstract EGU26-13829

Andes scientists presented reactive transport modeling that quantifies microbially accelerated weathering (MAW) and, critically, the fate of weathering products.  The team used the CrunchFlow reactive transport model to quantify changes in weathering rates, effects on soil pH, and the predominant sinks of weathering products. This research provides a basis for better understanding the factors determining where and when MAW yields carbon dioxide removal.

Key Findings:

• Reactive transport modeling with CrunchFlow reproduces the laboratory mesocosm weathering system and quantifies how microbial activity alters weathering rates, soil pH, and the fate of weathering products.

• Modeling indicates microbes can accelerate the weathering of some cation-bearing silicate minerals by as much as 7× in laboratory mesocosm experiments.

• Determining the predominant sinks of weathering products is essential to confirming carbon removal, with secondary carbonate precipitation emerging as a key mechanism linking accelerated weathering to durable CDR.

• The results carry direct implications for the measurement, reporting, and verification (MRV) of carbon removal from microbially accelerated weathering.

 

Application of Reactive Transport Modeling to Quantify Microbially Enhanced Weathering from a Soil Mesocosm Experiment

AGU 2025 - New Orleans, LA, USA · December 2025

To validate and quantify the experimental results from our CDR studies, this research uses the CrunchTope Reactive Transport Model (RTM). By modeling the geochemistry of the soil mesocosms, we constrained the kinetics of the weathering process. The study confirms that the formation of secondary minerals (calcium carbonates) acts as a sink for weathering products, preventing saturation and allowing the weathering process to continue at accelerated rates.

Key Findings:

• Modeling Validation: The reactive transport model successfully reproduced the temporal evolution of leachate pH and cation concentrations observed in the physical experiments.

• Coupled Processes: The model identified that anorthite (a calcium-rich feldspar) weathering coupled with secondary calcite formation is the primary driver of the observed carbon dioxide removal.

• Rate Quantification: Simulations that best matched the experimental data indicated that the anorthite weathering rate constant in MP1-treated soils was roughly 10 times higher than the baseline.

• Carbon Dioxide Removal (CDR): Consistency between model simulations and experimental data confirms that soil inorganic carbon (SIC) measurements provide an adequate and conservative basis for CDR accounting.

 

Harnessing Microbes to Weather Native Silicates in Agricultural Soils for Scalable Carbon Dioxide Removal

AGU 2025 - New Orleans, LA, USA · December 2025

This study provides a comprehensive look at how Andes' beneficial microorganism, Bacillus subtilis strain MP1, accelerates the natural silicate weathering process. The research spans from in vitro laboratory characterization to mesocosm studies and large-scale field trials. The results demonstrate that MP1 forms biofilms on mineral surfaces, creating specific microenvironments that significantly accelerate the release of base cations and the subsequent precipitation of stable carbonates.

Key Findings:

• Mechanism: MP1 forms robust biofilms on feldspar surfaces, generating a low pH microenvironment at the mineral interface for dissolution and a high pH environment at the biofilm surface for carbonate precipitation.

• Accelerated Weathering: In controlled soil columns, MP1 enhanced the native silicate weathering rate by over 6 times compared to untreated controls.

• Carbon Storage: Soil Inorganic Carbon (SIC) increased by 20% in MP1-treated soil columns.

• Field Performance: In a large-scale trial across 847 hectares in North Dakota, USA, MP1 treatment resulted in a gross accrual of 2.02 tonnes of inorganic Carbon per hectare annually.

• Agronomic Benefits: Soybean grain yield increased by 7.5% (0.21 tonnes/ha), and soils showed improved pH buffering compared to controls.

 

Andes is building a collaborative ecosystem to scale microbial carbon dioxide mineralization globally. Whether you are a researcher, an organization looking to support high-integrity carbon dioxide removal science, or an industry innovator, we want to hear from you. Let’s accelerate the path to scale carbon dioxide removal together.

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