Soil carbon markets continue to mature, and as they do so, the industry is increasingly curious about soil carbon measurement. New technologies are emerging, guidance is changing, and project developers, buyers and producers alike are wondering how to measure soil carbon accurately and at scale.
In our latest webinar, we dove into soil carbon measurement and heard one sentiment loud and clear: credibility for soil carbon projects depends on measurement systems that are both scientifically rigorous and practical to implement at scale.
During our discussion, "Evolutions in measurement tools and guidance: understanding Verra's soil sampling handbook and its implications on SOC measurement," experts from across the soil carbon ecosystem came together to discuss the evolving landscape of soil carbon measurement technologies, standards, and implementation challenges, including Verra's recent Soil Sampling Handbook and its impact on SOC measurement and reporting.
The conversation featured perspectives from project developers, measurement technology providers, scientists, and certification experts, all focused on one question: How do we build soil carbon markets that buyers, developers, and producers can trust?
Panelists
- Scott Dickson Dagondonixon — Head of Data Science, ChrysaLabs
- Wiebke Schulz — Certification Manager, ReGeneration
- Jim Kellner — Chief Scientist, Perennial
- Annie Leeson — Co-founder and CEO, Agricarbon
- Julian Kremers — Co-founder and CSO, Seqana
Moderated by Chris Dorich, Science Strategy Lead at Regrow. The webinar attracted an audience heavily engaged in VM0042 projects and highlighted the growing need for harmonized guidance across the sector.
The industry's central challenge: rigor vs. scalability
One of the webinar's strongest themes was the tension between scientific defensibility and operational scalability. Soil carbon projects are expected to deliver increasingly robust quantification, but they must also remain economically viable across large landscapes.
Buyers face growing reputational risk and therefore require clearer uncertainty communication. Developers are navigating rapidly evolving standards, statistical approaches, and emerging technologies that are changing the measurement landscape. The industry still lacks sufficient harmonization across methodologies and implementation practices.
The result is a market where project developers are often balancing budget realities with pressure to deliver highly defensible outcomes.
Why Verra's updated SSA Handbook matters
Much of the discussion focused on updates to Verra's Soil Sampling and Analysis (SSA) Handbook, which panelists described as an important step toward greater standardization and clarity.
A major topic was the introduction of the Economic Optimum Number of Samples (EONS), a framework designed to help projects balance scientific rigor with economic feasibility. Rather than prescribing one fixed sampling number, EONS allows developers to evaluate the tradeoffs between uncertainty, project heterogeneity, and cost.
Panelists noted that this approach helps reduce "MRV anxiety" for developers, creates clearer expectations around defensible sampling decisions, and avoids both oversampling driven by fear and undersampling driven by cost pressure. Ultimately, panelists agreed that flexibility is possible, but only when paired with transparent, quantifiable justification for measurements.
Quality assurance is just as important as sample quantity
Another recurring point was that sampling rigor is not only about the number of samples collected; it is also about the consistency and reproducibility of field operations.
Panelists discussed how variability in equipment, depth measurements, homogenization practices, core handling, and field team execution can all introduce significant uncertainty into datasets. Several speakers stressed that successful remeasurement campaigns require extremely detailed documentation and repeatable processes from the beginning.
"Soil is a volume, not a surface."
Emerging technologies are expanding the toolbox
The webinar also explored how emerging technologies, like Digital Soil Mapping (DSM), are expanding measurement possibilities. Rather than replacing physical sampling, DSM combines empirical soil samples, GPS data, remote sensing, weather data and topography to build predictive models capable of generating high-resolution carbon stock maps across large project areas.
These technologies can significantly improve spatial coverage and efficiency, but they do not eliminate the need for rigorous calibration and validation. Importantly, there is no universal "magic number" for sampling. Appropriate calibration depends on project heterogeneity, desired uncertainty thresholds, economics of the project, and expected sequestration rates.
Building trust through transparency
Across every topic, panelists agreed that transparency is foundational to trust. Panelists encouraged project developers, especially those entering the market for the first time, to invest time in understanding every step of the quantification process and selecting partners who can clearly explain methodologies, assumptions, and tradeoffs.
The discussion reinforced that the future success of soil carbon markets will depend on shared standards, publicly verifiable outcomes, clear uncertainty communication, robust validation processes, and early demonstration of success for emerging technologies.
As the ecosystem evolves, the path forward will require collaboration across developers, scientists, technology providers, standards bodies, and buyers alike.
We're grateful for all speakers and attendees for contributing to a thoughtful and technically grounded discussion on one of the most important challenges facing the carbon market today.