Case study: Soil carbon MRV & incentives — a leading company's implementation and lessons learned

When Indigo Agriculture launched its soil carbon credit program in 2019, the company enrolled 2,500 growers across 4 million acres in the first two years, generating over 500,000 carbon credits from regenerative agriculture practices. By 2024, Indigo had issued more than 750,000 credits registered on the Climate Action Reserve registry, making it the largest agricultural carbon credit originator in the United States (Indigo Agriculture, 2025). Yet the path from concept to scale was not smooth: verification costs consumed 35 to 45% of per-credit revenue in the first cohorts, grower attrition reached 28% after year one, and independent analyses questioned whether the measurement, reporting, and verification (MRV) methodology could reliably detect changes as small as 0.3 to 0.5 tonnes of carbon per hectare per year. This case study examines how Indigo built, iterated, and scaled its soil carbon MRV and incentive program, the failures that shaped its current approach, and the lessons applicable to any organization entering this market.

Why It Matters

Agriculture accounts for approximately 10% of US greenhouse gas emissions, but farmland also represents one of the largest potential carbon sinks. The US Department of Agriculture estimates that improved management of the nation's 900 million acres of cropland and pastureland could sequester 100 to 200 million tonnes of CO2 equivalent annually, roughly 2 to 4% of total US emissions (USDA, 2024). Carbon credit markets offer a financial mechanism to incentivize this sequestration, but only if the measurement systems are credible and the economics work for growers.

The voluntary carbon market for soil carbon reached $350 million in transaction value in 2024, up from $50 million in 2020, but also attracted intense scrutiny from buyers, academics, and regulators. A 2024 study published in Nature Food found that 40% of soil carbon credits reviewed relied on modeled rather than measured data, with uncertainty ranges of plus or minus 50% or more at the field level (Oldfield et al., 2024). For companies purchasing these credits to meet climate commitments, credibility gaps create reputational and financial risk. For growers, unreliable programs erode trust and reduce participation. Indigo's experience demonstrates both the potential and the difficulty of building a soil carbon MRV system that works at scale.

Key Concepts

Soil carbon MRV encompasses the methods used to quantify changes in soil organic carbon (SOC) stocks resulting from shifts in agricultural practices. Three primary approaches exist: direct soil sampling with laboratory analysis, biogeochemical process models such as DNDC and DayCent, and remote sensing using satellite imagery and spectral analysis. Each approach involves tradeoffs between accuracy, cost, and scalability. Direct sampling provides the highest accuracy (plus or minus 10 to 15% at the field level with adequate sampling density) but costs $15 to $25 per acre for initial baseline plus annual monitoring. Process models can scale to millions of acres at $0.50 to $2 per acre but carry uncertainty ranges of 30 to 60% without calibration data. Remote sensing sits between the two on cost and accuracy but requires ground-truth validation.

Carbon credit protocols define the rules governing baseline establishment, additionality determination, permanence requirements, and credit issuance. The Climate Action Reserve's Soil Enrichment Protocol, the Verra VM0042 methodology, and the Gold Standard's Soil Organic Carbon Framework each take different approaches to these questions. Additionality, the requirement that credited sequestration would not have occurred without the carbon market incentive, remains the most contentious element.

Grower incentive structures determine how revenue from carbon credit sales flows to farmers. Payment models range from per-acre practice payments ($5 to $25 per acre per year) to per-tonne outcome payments ($15 to $40 per tonne of verified sequestration). The choice between practice-based and outcome-based payments has profound implications for grower risk, program scalability, and credit buyer confidence.

What's Working

Hybrid MRV Stacks

Indigo's most significant methodological evolution was the shift from a sampling-only approach to a hybrid MRV stack combining direct soil sampling, biogeochemical modeling, and remote sensing. In its initial 2019 to 2020 cohorts, Indigo relied primarily on direct soil sampling at densities of one core per 10 acres, collected at 0 to 30 cm depth. This approach generated defensible data but at costs of $18 to $22 per acre, consuming most of the carbon credit revenue on MRV alone.

By 2022, the company had developed a stratified sampling protocol that used satellite-derived vegetation indices and soil maps to identify zones within fields where carbon change was most likely, then concentrated sampling in those zones while using calibrated process models (a modified DayCent framework) to estimate changes across the remainder. This approach reduced per-acre MRV costs to $6 to $9 while maintaining field-level uncertainty below plus or minus 25%, sufficient to meet the Climate Action Reserve's quantification requirements (Indigo Agriculture, 2025).

Bayer Crop Science adopted a similar hybrid approach for its Carbon Initiative, enrolling over 1,500 growers across 800,000 acres by 2024. Bayer uses the DNDC model calibrated with approximately 5,000 soil samples from enrolled fields, combined with satellite-based crop type and tillage detection. The company reported MRV costs of $4 to $7 per acre at scale, with independent validation by the Soil Health Institute confirming model predictions within plus or minus 20% of measured values across 85% of validation sites (Bayer, 2024).

Practice Change Verification at Scale

Verifying that growers actually adopt the practices for which credits are issued (cover cropping, reduced tillage, nutrient management) has proven more tractable than quantifying carbon outcomes. Indigo deployed a combination of satellite-based tillage detection (using Sentinel-2 imagery at 10 m resolution), cover crop verification through normalized difference vegetation index (NDVI) analysis during fallow periods, and grower-submitted field records validated against agronomic plausibility checks.

This system correctly identified practice adoption on 94% of enrolled fields in 2023, with a false positive rate of 3%, according to an independent audit by Aster Global Environmental Solutions (Aster Global, 2024). The ability to verify practices remotely at near-zero marginal cost per field has been a critical enabler of program scaling.

Grower Engagement and Retention

Indigo's initial grower attrition rate of 28% after the first year dropped to 12% by the 2022 cohort, driven by three changes: shifting from outcome-based payments (which created uncertainty for growers about their eventual compensation) to a hybrid model combining a guaranteed practice payment of $10 to $15 per acre with a bonus payment tied to verified carbon outcomes; providing agronomic advisory services that helped growers optimize cover crop species selection and reduced tillage transitions to maintain or improve yields; and simplifying enrollment and data submission through a mobile application that reduced grower time commitment from an estimated 8 to 12 hours per enrollment to under 2 hours.

Nutrien, the world's largest crop input retailer, has achieved similar retention by embedding carbon program enrollment within its existing agronomic services relationships. Nutrien's Carbon Program, operating across 3.2 million acres as of 2024, leverages its network of 3,500 crop consultants to provide in-person support, resulting in first-year attrition of only 9% (Nutrien, 2025).

What's Not Working

Permanence and Reversal Risk

Soil carbon sequestration is inherently reversible: a grower who adopts no-till for five years and then returns to conventional tillage can release accumulated carbon within two to three growing seasons. Indigo addresses permanence through a 15% buffer pool (withholding 15% of credits from each issuance as insurance against reversals) and a 10-year contractual commitment from growers. However, enforcing 10-year commitments with thousands of independent farm operators, many of whom farm rented land with lease terms of 1 to 3 years, has proven difficult. In 2023, approximately 6% of enrolled acres exited the program before the contractual term, primarily due to land sales or lease non-renewals (Indigo Agriculture, 2025).

The Climate Action Reserve protocol requires monitoring for 25 years after the last credit issuance, creating long-term liability that no soil carbon program has yet fully addressed. Critics argue that the 15 to 20% buffer pool standard across most protocols is insufficient to cover reversal risk over multi-decade timeframes, particularly given the potential for drought, wildfire, or policy changes to drive widespread practice reversion.

Baseline Uncertainty and Additionality

Establishing accurate baselines for soil organic carbon is complicated by natural variability. SOC levels vary by 20 to 40% within a single field due to differences in topography, soil texture, drainage, and management history. Indigo's initial baseline sampling at one core per 10 acres captured only coarse-scale patterns, leading to baseline estimates with uncertainty of plus or minus 30 to 40%. When the expected annual carbon gain is 0.3 to 0.8 tonnes per hectare, a 30% baseline uncertainty can make it statistically impossible to detect a real signal within the first 3 to 5 years of practice change.

Additionally, many growers enrolling in carbon programs had already begun transitioning to regenerative practices before enrollment, raising additionality questions. A 2024 analysis by CarbonPlan found that 30 to 50% of fields enrolled in major soil carbon programs showed evidence of practice change predating program enrollment by 1 to 3 years, suggesting that a significant fraction of issued credits may not represent truly additional sequestration (CarbonPlan, 2024).

Credit Pricing Below Grower Opportunity Costs

Voluntary market prices for soil carbon credits ranged from $15 to $35 per tonne in 2024, down from peaks of $40 to $50 in 2022. After deducting MRV costs, registry fees, and program overhead (which together consume 40 to 55% of gross credit revenue), net grower payments typically range from $8 to $18 per tonne, translating to $3 to $12 per acre per year. For many growers, particularly in high-value crop regions, this payment fails to cover the yield risk and transition costs associated with adopting new practices. Cover crop seed alone costs $15 to $40 per acre, meaning that in many scenarios the carbon payment does not cover even the direct input costs of the credited practice.

Key Players

Established Companies

Indigo Agriculture: largest agricultural carbon credit originator in the US with over 750,000 credits issued across 4 million enrolled acres.

Bayer Crop Science: Carbon Initiative enrolling 1,500+ growers and integrating MRV with its digital farming platform Climate FieldView.

Nutrien: embeds soil carbon enrollment into existing agronomic services relationships across 3.2 million acres via its retail crop consultant network.

Corteva Agriscience: partners with Granular to offer carbon program participation alongside precision agriculture services.

Startups

Yard Stick PCS: develops rapid in-field soil carbon measurement using penetrometer-mounted near-infrared spectroscopy, reducing per-sample cost to $2 to $5.

Perennial: satellite and AI-based soil carbon mapping platform providing continuous monitoring at under $1 per acre.

Regrow Ag: combines remote sensing with the DeNitrification-DeComposition (DNDC) model for scalable MRV across large acreages.

Investors and Funders

Microsoft Climate Innovation Fund: purchased soil carbon credits from multiple programs and invested in MRV technology development.

Breakthrough Energy Ventures: invested in Yard Stick PCS and other agricultural MRV companies.

USDA Partnerships for Climate-Smart Commodities: allocated $3.1 billion in grants supporting soil carbon measurement and practice adoption across 141 projects.

Action Checklist

• Adopt a hybrid MRV approach combining targeted direct sampling with calibrated process models and remote sensing to balance accuracy against cost
• Design grower payment structures that include guaranteed practice payments alongside outcome-based bonuses to reduce farmer risk and improve retention
• Invest in satellite-based practice verification for cover cropping and tillage, which can scale to millions of acres at near-zero marginal cost
• Establish baseline sampling at sufficient density (minimum one composite sample per 5 acres in variable fields) to detect annual carbon changes within 3 years
• Negotiate permanence commitments that account for land tenure realities, including provisions for credit transfer when land changes hands
• Integrate carbon program enrollment with existing agronomic advisory services to reduce grower friction and improve long-term engagement
• Maintain transparent reporting of uncertainty ranges alongside credit claims to build buyer confidence and differentiate from lower-quality programs

FAQ

Q: How long does it take to detect measurable soil carbon changes from regenerative practices? A: Most peer-reviewed studies find that statistically significant changes in SOC stocks require 3 to 7 years of sustained practice change, depending on soil type, climate, and practice intensity. Sandy soils in warm climates may show detectable changes within 2 to 3 years, while heavy clay soils in cooler regions may require 5 to 10 years. Programs that issue credits in year one based on modeled projections carry higher uncertainty than those that wait for measured verification.

Q: What is the typical cost to generate and verify one soil carbon credit? A: Total costs, including MRV, registry fees, program administration, and grower acquisition, range from $8 to $20 per credit for programs at scale (>100,000 acres). Smaller programs may face costs of $25 to $40 per credit due to fixed overhead spread across fewer tonnes. Indigo's hybrid MRV approach brought all-in costs to approximately $12 per credit by 2024, leaving $8 to $18 per credit for grower payments at market prices of $20 to $30.

Q: How do soil carbon credits compare to other nature-based carbon removal approaches? A: Soil carbon credits are generally less expensive than direct air capture ($400 to $1,000+ per tonne) but carry higher permanence risk than geological storage. Compared to forestry credits ($10 to $30 per tonne), soil carbon credits offer comparable pricing but face greater measurement challenges due to the subtlety of underground carbon changes versus above-ground biomass that can be measured via lidar or satellite. Buyers increasingly stack soil carbon purchases with more permanent removal methods to diversify risk.

Q: What practices generate the most soil carbon sequestration per acre? A: Cover cropping combined with no-till management consistently shows the highest sequestration rates in US agricultural studies, averaging 0.4 to 0.8 tonnes CO2 per hectare per year. Adding diverse crop rotations and integrating livestock grazing on cropland can increase rates to 1.0 to 2.0 tonnes per hectare per year in favorable conditions. However, results vary widely by region, soil type, and climate, and practitioners should rely on local field trial data rather than national averages when projecting outcomes.

Sources

• Indigo Agriculture. (2025). Carbon by Indigo: Program Performance and Methodology Report 2024. Boston, MA: Indigo Ag Inc.
• United States Department of Agriculture. (2024). Quantifying the Potential of US Cropland and Pastureland for Carbon Sequestration. Washington, DC: USDA.
• Oldfield, E. E., et al. (2024). "Systematic assessment of soil carbon credit quality in the voluntary market." Nature Food, 5(3), 218-229.
• Bayer Crop Science. (2024). Carbon Initiative: Annual Report on Enrollment, MRV Performance, and Grower Outcomes. St. Louis, MO: Bayer.
• CarbonPlan. (2024). Additionality Assessment of Agricultural Carbon Credit Programs. San Francisco, CA: CarbonPlan.
• Aster Global Environmental Solutions. (2024). Independent Verification of Satellite-Based Practice Detection in Agricultural Carbon Programs. Cary, NC: Aster Global.
• Nutrien. (2025). Carbon Program: Scale, Performance, and Grower Retention Metrics. Saskatoon, SK: Nutrien Ltd.
• USDA Partnerships for Climate-Smart Commodities. (2024). Program Overview and Funded Projects Summary. Washington, DC: USDA.