Isometric has released a draft protocol for Improved Soil Management (ISM) for public consultation. The protocol outlines requirements and procedures for projects that increase the amount of carbon stored in soils through less intensive tillage, cover cropping, and the application of beneficial microorganisms.
How Improved Soil Management works
Soils are the largest terrestrial reservoir of carbon on Earth, containing nearly 3 trillion tonnes of carbon, approximately three times as much as the atmosphere. Soils naturally accumulate carbon as plants capture carbon dioxide from the air and transfer it into the soil through their roots and when they decompose.
Actively improving how land is managed can significantly increase how much carbon is stored in soil. Improved management of croplands and grasslands could remove up to 430 million tonnes of carbon dioxide from the atmosphere every year, more than the UK’s annual carbon footprint.
ISM techniques include reducing tillage—plowing or turning the soil—to keep stored carbon underground; growing cover crops between harvests to maintain carbon storage; and adding beneficial microorganisms to help plants access soil nutrients, grow faster, and store more carbon.
Alongside removing carbon, ISM can enhance drought resilience, improve agricultural productivity, reduce reliance on synthetic fertilizers, increase biodiversity above and below ground, and reduce nutrient runoff into waterways. ISM can also provide an additional income stream for local farming communities while increasing the soil’s resilience to pests, disease, and climate change.
The Improved Soil Management Protocol
The ISM Protocol sets out how these activities are measured, credited, and monitored. It takes a scientifically rigorous approach to Measurement, Reporting, and Verification (MRV), requiring carbon removal to be measured through direct soil sampling alone, or in combination with validated modeling approaches. Projects must account for all associated greenhouse gas emissions, from equipment use to project-related land management.
Each project has a defined "project commitment period" of between 40 and 100 years, split into two phases. During the crediting period, the project removes carbon from the atmosphere. During the monitoring period that follows, the project ensures the carbon remains stored. Credit durability is set at half the total commitment period.
The ISM Protocol takes an adaptive approach to buffer pools, adjusting contributions to reflect each project's actual reversal risk. Suppliers can reduce their buffer pool contributions by completing a project-specific risk assessment, which accounts for factors including the risk of extreme weather, long-term financial planning, and project development track record.
Projects must also meet robust environmental and social safeguards, including a minimum 20% revenue share for enrolled landowners in smallholder projects, reflecting their role in maintaining the carbon stocks, and meaningful community engagement throughout the project lifetime. Where project activities affect Indigenous Peoples, projects must follow the principles of Free, Prior, and Informed Consent (FPIC) as outlined by the UN Declaration on the Rights of Indigenous Peoples.
Supporting modules
Specific ISM approaches are supported by their own modules. The Cropland Management Module, in public consultation alongside the ISM Protocol, covers projects that use reduced tillage, cover cropping, and beneficial microorganisms to remove carbon from croplands. A module covering ISM in grazing lands is currently under development.
Crediting emissions reductions
The ISM Protocol also enables specific emissions reductions to be credited alongside removals. Agricultural emissions are tightly linked to the same management practices that ISM targets, which means projects can often reduce emissions and remove carbon through a single set of interventions.
The Agricultural Practices Reductions Module, also in public consultation, allows suppliers to quantify the greenhouse gas emissions their projects avoid, primarily nitrous oxide and carbon dioxide, from practices such as reduced synthetic fertilizer use and less frequent tractor passes under reduced tillage. These reductions are an integral benefit of improved soil management, and will be accounted for and credited separately from the removals quantified under the ISM Protocol.
To credit reductions, ISM projects must demonstrate that:
- reductions are causally linked to specific, identifiable management practices;
- those practices can be altered to reduce emissions and are not already widely adopted in the relevant crop, geography, and production context; and
- pre- and post-intervention data can be collected to estimate both realized emissions and counterfactual emissions (what emissions would have been without the intervention).
The protocol and modules were developed through collaboration between Isometric's Science Team and reviewers from the independent Science Network of more than 400 academic experts and practitioners.
Isometric welcomes comments from buyers, suppliers, and scientists during the 30-day public consultation period ending on June 11, 2026.
