Agricultural Practices Reductions

Improved soil management (ISM) practices that sequester carbon in agricultural soils frequently deliver concurrent reductions in greenhouse gas (GHG) emissions. Changes to tillage regime, fertilizer application, and cover cropping alter the flux of nitrous oxide (N₂O), carbon dioxide (CO₂), and methane (CH₄) from agricultural land, producing emission reductions that are mechanistically distinct but operationally inseparable from the soil organic carbon (SOC) removals targeted by the Improved Soil Management Protocol.

Agriculture is a significant source of direct GHG emissions globally. Synthetic nitrogen fertilizer application is the dominant anthropogenic driver of N₂O emissions, a greenhouse gas with a 100-year global warming potential (GWP) of 273¹. Fossil fuel combustion during field operations, principally diesel use in tillage, contributes direct CO₂, N₂O, and CH₄ emissions. These emission sources are causally linked to identifiable management practices that can be modified to reduce emissions while simultaneously supporting SOC accumulation.

This Module establishes the requirements for quantifying, reporting, and verifying emission reductions achieved through agricultural practice changes that are implemented as part of a project generating carbon dioxide removals under the Improved Soil Management Protocol. It provides a framework for crediting reductions that are conservatively quantified. Reductions credited under this Module must be submitted alongside corresponding removals for the same Reporting Period; they are not eligible to be credited independently of removals.

This Module is designed to be conservative in scope. Only emission reduction categories that meet three essential criteria are eligible for crediting: (1) the emissions are causally linked to specific, identifiable management practices; (2) the management practices can be altered to reduce emissions and are not already widely adopted in the relevant crop, geography, and production context; and (3) pre- and post-intervention physical data can be collected to support estimates of realized emissions and counterfactual emissions.

The quantification of soil organic carbon removals is governed separately by the Improved Soil Management Protocol and the Cropland Management Module. The combined climate benefit of a project is expressed as a GHG Entry comprising both removals and reductions for a given Reporting Period:

$$GHG \ Entry = CO₂e_{Removals} + CO₂e_{Reductions}$$

Where:

• CO₂eRemovals are the net removals, quantified in accordance with the Improved Soil Management Protocol. CO₂e_Removals must be greater than zero.
• CO₂eReductions are net reductions, quantified in accordance with this Module. CO₂e_Reductions may be zero.

This Module relies on and is intended to be compliant with the following standards and protocols:

• The Isometric Standard
• The Improved Soil Management Protocol
• ISO 14064-2: 2019 — Greenhouse Gases — Part 2: Specification with guidance at the project level for quantification, monitoring, and reporting of greenhouse gas emission reductions or removal enhancements

Additional reference standards that inform the requirements and overall practices incorporated in this Module include:

• ISO 14064-3: 2019 — Greenhouse Gases — Part 3: Specification with Guidance for the Verification and Validation of greenhouse gas statements
• ISO 14040: 2006 — Environmental Management — Lifecycle Assessment — Principles & Framework
• ISO 14044: 2006 — Environmental Management — Lifecycle Assessment — Requirements & Guidelines

Protocols and methodologies that were assessed as part of a literature review during the development of this Module include:

• VM0042 Methodology for Improved Agricultural Land Management, v2.2, Verra, 2025
• VMD0053 Model Calibration, Validation, and Uncertainty Guidance for Biogeochemical Modeling, v2.1, Verra, 2025
• Soil Enrichment Protocol, v1.1, Climate Action Reserve
• 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Volume 4, Chapter 11 (N₂O Emissions from Managed Soils)
• 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Volume 4, Chapter 10 (Emissions from Livestock and Manure Management)

This initial version of the module aims to be scientifically stringent and robust and thus scopes the limited set of agricultural practice emissions reductions sources with approaches that Isometric has confidence in the verifiability and quantification of along with soil carbon interventions scoped in the Improved Soil Management Protocol v1.0.

Isometric will continue to evaluate various sources of agricultural practices with emissions reductions. Future versions of this module will include revised and/or expanded emissions reductions sources eligible for crediting. Revised or additional agricultural practices emissions reductions may relate to existing interventions as scoped in the Improved Soil Management Protocol v1.0 and may expand as additional interventions are scoped in future versions of the Improved Soil Management Protocol.

To qualify for crediting under this Module, a Project must meet all of the conditions specified in this section, in addition to all requirements of the Improved Soil Management Protocol and the Isometric Standard.

Emission reductions under this Module are only eligible for Projects that are concurrently generating soil organic carbon removals under the Improved Soil Management Protocol. This Module does not support standalone emission reduction projects.

This Module applies to emission reductions arising from the following agricultural practice changes, where the practice change is implemented as part of a project generating removals under the Improved Soil Management Protocol. Each eligible practice must satisfy the three inclusion criteria described in Section 1

Reductions in synthetic nitrogen fertilizer application directly lower N₂O emissions from managed soils. N₂O is produced through nitrification and denitrification processes in soil, and emissions scale with the quantity of reactive nitrogen applied. Where project activities result in a measurable decrease in synthetic nitrogen application relative to the baseline, the resulting reduction in direct N₂O emissions is eligible for crediting.

Reductions in synthetic nitrogen application are eligible for crediting where the Project Proponent can demonstrate that the reduction does not result in material yield losses at the project level (see Section 4.1.1.1). Strong candidate cropping systems are those where the project introduces nitrogen-fixing plants (e.g., leguminous cover crops) that functionally replace a portion of the synthetic nitrogen requirement. The replacement of the nitrogen function by biological fixation mitigates the primary leakage risk that reduced nitrogen inputs will reduce yields and displace production elsewhere.

Only direct N₂O emissions from the application of synthetic nitrogen to soils are eligible. Embodied emissions associated with the production and transport of fertilizer are excluded from the scope of creditable reductions, consistent with the treatment of avoided upstream emissions across other Isometric Protocols.

Fertilizer reduction carries a material leakage risk through yield-reductions. The Cropland Management Module details an approach for assessing leakage impacts from production shortfalls due to yield reductions associated with reductions in fertilizer application. At a Project level, productivity declines in excess of 15% of the historical rates are ineligible to protect against systematic changes that may emerge from large-scale productivity displacement.

See Section 8.3 of the Cropland Management Module for a full description of leakage guardrails and estimation.

Where a project activity involves a transition from conventional tillage to reduced or no-tillage, the reduction in on-farm diesel combustion associated with fewer tractor passes is eligible for crediting. Only direct CO₂, N₂O, and CH₄ emissions from diesel combustion are included; upstream emissions from fuel production and supply are excluded.

Diesel reduction credits are only eligible where the reduced tillage practice is implemented as part of the same project activity generating soil organic carbon removals. The tillage change must be documented in the PDD and evidenced through farm management records in accordance with the Improved Soil Management Protocol..

The baseline scenario represents the business-as-usual condition, describing the expected GHG emissions from agricultural practices in the absence of the Project. The baseline must be established for each eligible practice and for each stratum.

The baseline must be constructed from a lookback period of 5 years immediately preceding the project start date. A longer lookback period is preferred where data are available.

The baseline fertilizer application rate for each field or stratum must be set as the lesser of:

• Farm-level historical application rate: the average annual synthetic nitrogen application rate (kg N/ha) over the baseline period, as evidenced by farm management records, purchase receipts, or other verifiable documentation; and
• Regional benchmark application rate: the regional mean synthetic nitrogen application rate for the relevant crop, derived from publicly available data (e.g., USDA ERS Fertilizer Use and Price data, university extension service recommendations, or equivalent national data).

Where farm-level records are unavailable for the full baseline period, the regional benchmark rate must be used. Where farm-level records show application substantially above the regional benchmark, the baseline is capped at the regional mean.

The baseline must document the pre-project tillage regime, including operation types, frequency of passes, equipment used, and associated diesel consumption per hectare. Where direct records are not available, published estimates for the relevant crop, equipment type, and geography must be used (see Section 9.3.2).

The baseline tillage regime must be evidenced by farm management records, contractor invoices, or farmer attestation supported by corroborating evidence.

Evidence requirements for the baseline scenario are consistent with the evidence requirements in Section 4 of the Improved Soil Management Protocol. At minimum, the following must be evidenced for each enrolled field:

• The field was under active agricultural production during the baseline period.
• The baseline management practices were consistent during the baseline period.
• The field was not subject to practice changes motivated by anticipated carbon finance during the baseline period.
• The project area must not have been cleared of native ecosystems within the 10 years immediately preceding the project start date.

Isometric retains the right to use historical remote sensing data to confirm that the baseline scenario and historical land use have been accurately described.

The baseline must be renewed at each Crediting Period renewal, in accordance with the Isometric Standard. At renewal, the Project Proponent must re-establish the baseline using the most recent available data including updates as needed to:

• Emissions factors
• Published estimates of relevant crops and equipment type in the geographic area (for reduced and no-till)
• Regional mean synthetic nitrogen application rates for relevant crops derived from publicly available data (for fertilizer application)

All Project Timelines outlined in Section 5 of the Improved Soil Management Protocol apply in full, with one exception.

The Improved Soil Management Protocol provides that in the event of project failure, all Credits issued under the Project will be cancelled. This cancellation provision applies to carbon dioxide removal credits issued under the Project.

Emission reduction credits issued under this Module and verified for a completed Reporting Period prior to the date of project failure are not subject to cancellation. The emission reductions credited under this Module represent permanent, non-reversible atmospheric benefits. Once verified, the avoided emissions cannot be reversed by subsequent changes in land management or project status.

This treatment is consistent with Section 2.5.7 and Section 2.5.9 of the Isometric Standard, which recognise that some Reductions are permanent with no risk of reversal.

In the event of project failure, the Project is immediately ineligible to generate further emission reduction credits under this Module.

All ESS requirements of Section 6 of the Improved Soil Management Protocol and the Isometric Standard apply in full. No additional ESS requirements are introduced by this Module.

Projects must assess the environmental and social risks of the practice changes credited under this Module including risks from reduced fertilizer application and changes to tillage regime as part of their overarching ESS assessment required by the Protocol.

All requirements in Section 7 of the Improved Soil Management Protocol apply in full to emission reductions under this Module, including requirements for the PDD, Validation and Verification, Verification Materiality, site visits, verifier qualifications, ownership, and data sharing. The following Module-specific additions and modifications apply.

In addition to the PDD requirements in the Improved Soil Management Protocol and the Isometric Standard, the PDD must include:

• a description of the baseline conditions for each eligible reduction practice, including the baseline fertilizer application rate (Section 4.2.2) and baseline tillage regime (Section 4.2.3);
• a description of the quantification strategy, including the emission factor method(s) selected for N₂O (Section 9.3.1) and the fuel consumption approach for diesel (Section 9.3.2);
• a description of the leakage assessment methodology, including data sources for regional yield benchmarks and the baseline productivity ratio; and
• the monitoring plan for reduction-specific parameters (Section 10).

Where a Project generates both removal and reduction credits, a single PDD is sufficient, provided all requirements of both the Protocol and this Module are met.

In addition to the VV requirements in the Improved Soil Management Protocol, the VVB must:

• Verify that the reduction quantification approach adheres to Section 9;
• Verify the leakage assessment, including the productivity ratio calculation and yield data sources; and
• For aggregated projects, ensure that the site visit plan includes a statistically representative sample of enrolled fields, with the sampling methodology documented.

VVB teams must demonstrate expertise in nitrogen cycling and emission reduction quantification from agricultural practice changes, in addition to the competencies required by the Improved Soil Management Protocol.

All ownership requirements in the Improved Soil Management Protocol and the Isometric Standard apply. In addition, where a Project generates both removal and reduction credits, ownership of both credit types must be assigned to the same Project Proponent. Separate ownership of removal and reduction credits from the same Project is not permitted.

All additionality requirements in the Improved Soil Management Protocol and the Isometric Standard apply. The following Module-specific provisions also apply.

Because emission reductions under this Module are only creditable as part of a Project concurrently generating removals, the additionality of the reduction activities is assessed in the context of the broader project. The additionality test applies to the bundle of practice changes at the project level, not to individual reduction categories in isolation.

Agricultural practice changes that reduce GHG emissions frequently generate co-benefits that may qualify for separate payments under conservation schemes or other payments for ecosystem services. The stacking disclosure and additionality requirements in the Isometric Standard apply.

In addition, any field already receiving carbon-related incentive payments from another programme for the same practice change (e.g., selling no-till credits to one programme and cover crop credits to Isometric) must be disclosed and excluded from the reduction credit calculation for the overlapping practice.

The Common Practice analysis must be conducted in accordance with the requirements in Section 7.5 of the Improved Soil Management Protocol and the Isometric Standard, applied on a practice by practice basis.

In addition, for the purposes of this Module, the Common Practice analysis should account for adoption trends. Where a practice shows a stable adoption rate below 20% over 5 or more years, this constitutes strong evidence of additionality. Where a practice shows a rapidly increasing adoption rate — even if currently below 20% — the Project Proponent must provide additional justification that Carbon Finance is a material driver of adoption above the trend.

All uncertainty requirements in the Improved Soil Management Protocol and the Isometric Standard apply. Module-specific uncertainty discount, applied based on the tier of emission factor and approach to activity data determination, are specified in Section 9.6.

All data sharing requirements in the Improved Soil Management Protocol apply. In addition, the following data specific to this Module must be made available through Isometric's platform:

• Emission factors used for N₂O and diesel quantification
• Activity data (nitrogen application rates, fuel consumption)
• Model specifications and output (where Method 3 is used)
• Yield data used in the leakage assessment

The Reporting Period for emission reductions must align with the Reporting Period defined for the associated removal credits under the Improved Soil Management Protocol. Reductions and Removals must be submitted together as part of a GHG Entry for the same Reporting Period. All reporting period requirements in Section 9.1 of the Improved Soil Management Protocol apply.

This Module covers the GHG SSRs relevant to the quantification of emission reductions. SSRs relevant to SOC removals are governed by the Improved Soil Management Protocol. The general system boundary principles and GHG accounting requirements in Section 8.1 of the Improved Soil Management Protocol and the GHG Accounting Module v1.1 apply.

The system boundary for reductions must include the SSRs set out in Table 1. If any SSRs are deemed not appropriate, they may be excluded with robust justification in the PDD.

Table 1: System Boundary for Emission Reductions

Reductions in emissions associated with the production, transport, or supply chain of agricultural inputs are excluded from creditable reductions, as established in Section 4.1.3. This exclusion is conservative and consistent with the GHG Accounting Module v1.1. Any positive emissions associated with these sources must be included in The Project's GHG statement in accordance with Table 1 of the Improved Soils Management Protocol.

Strata defined for reductions should align with the strata defined for removals under the Improved Soil Management Protocol and the Cropland Management Module where possible. Where reduction-specific criteria require finer disaggregation, additional sub-strata may be created. All strata must be documented in the PDD.

• Crop type. Stratify by primary crop or crop rotation. Where rotations are practised, the stratum must reflect the rotation as a whole, provided it is consistent across baseline and project periods.
• Baseline nitrogen application rate category. Low ( 75% of regional mean), moderate (75–125%), and high ( 125%). Regional mean per Section 4.2.2.
• Baseline tillage regime. For diesel reductions: conventional tillage, reduced tillage, and the project scenario (no-till / direct seeding).
• Geography. Projects spanning multiple second-order administrative jurisdictions must stratify by jurisdiction.

• Soil texture (coarse, medium, fine) — influences N₂O emissions.
• Soil organic carbon content (low 1%, moderate 1–3%, high 3%).
• Climate zone (Köppen-Geiger classification for multi-zone projects).

Where monitoring data cannot distinguish between sub-categories within a stratum, the most conservative parameter values must be applied (the combination producing the lowest net reductions).

The baseline scenario is defined in Section 4.2. Baseline quantification accounts for N₂O emissions from fertilizer (Section 9.2.1) and direct GHGs from diesel combustion during tillage (Section 9.2.2).

The Improved Soil Management Protocol provides general leakage requirements for ISM projects, and the Cropland Management Module details the specific approach assessing productivity declines and quantifying associated leakage emissions. Per Section 8.2.1.1 of the Improved Soil Management Protocol, all leakage emissions occurring as a result of the project shall be assessed against removals.

$$CO_2e_{Reduction,RP} = CO_2e_{Baseline,RP} - CO_2e_{Project,RP}$$

(Equation 1)

Where:

• $CO_2e_{Reduction,RP}$ is the net CO₂e reduction for the Reporting Period, in tonnes CO₂e. Must be zero or positive.
• $CO_2e_{Baseline,RP}$ is the CO₂e emissions that would have occurred absent the project (Section 9.2), in tonnes CO₂e.
• $CO_2e_{Project,RP}$ is the CO₂e emissions from project activities (Section 9.4), in tonnes CO₂e.

The final credited reduction is:

$$CO_2e_{Credited,RP} = CO_2e_{Reduction,RP} \times (1 - D_{uncertainty})$$

(Equation 2)

Where $D_{uncertainty}$ is the total uncertainty discount factor (Section 9.6).

$$CO_2e_{Baseline,RP} = CO_2e_{BL,N_2O,RP} + CO_2e_{BL,Diesel,RP}$$

(Equation 3)

$$CO_2e_{BL,N_2O,RP} = \sum\limits_g \left( Q_{N,BL,g} \times A_g \times EF_{N_2O,g} \times \frac{44}{28} \times 10^{-3} \times GWP_{N_2O} \right)$$

(Equation 4)

Where:

• $Q_{N,BL,g}$ is the baseline synthetic nitrogen application rate for stratum $g$ (kg N/ha/RP), set as the lesser of farm-level historical and regional benchmark per Section 4.2.2.
• $A_g$ is the area of project fields in stratum $g$ (ha).
• $EF_{N_2O,g}$ is the emission factor for direct N₂O from nitrogen inputs (kg N₂O-N/kg N-input), per Section 9.3.1.
• $\frac{44}{28}$ is the molecular weight conversion from N₂O-N to N₂O.
• $10^{-3}$ converts kg to tonnes.
• $GWP_{N_2O}$ is the 100-year GWP of N₂O (currently 273).

$$CO_2e_{BL,Diesel,RP} = \sum\limits_g \left( \sum\limits_p \left( N_{passes,BL,p,g} \times FC_{p,g} \right) \times A_g \times EF_{diesel} \times 10^{-3} \right)$$

(Equation 5)

Where:

• $N_{passes,BL,p,g}$ is the number of passes of tillage operation type $p$ under the baseline regime for stratum $g$.
• $FC_{p,g}$ is the fuel consumption rate (litres diesel/ha/pass), per Section 9.3.2.
• $EF_{diesel}$ is the emission factor for direct diesel combustion, inclusive of CO₂, CH₄, and N₂O (default for 100% petroleum diesel: 2.78 kg CO₂e/litre, comprising 2.70 kg CO₂ + 0.01 kg CO₂e from CH₄ + 0.07 kg CO₂e from N₂O, per EPA GHG Emission Factors Hub 2025, using AR6 GWPs). Where biodiesel or renewable diesel was used in baseline operations, a fuel-type-specific emission factor must be applied (see Section 9.3.2).

Emission factors (EFs) must be determined for each stratum using one of the following methods. The selected method(s) must be described in the PDD.

Method 1: IPCC Tier 1 Default Emission Factors. Default EF of 0.01 kg N₂O-N/kg N-input (IPCC 2019 Refinement, Vol 4, Ch 11, Table 111²). Subject to the largest uncertainty discount (Section 9.6).

Method 2: Country-Specific or Regional Emission Factors. Peer-reviewed, published EFs specific to the project country or region, derived from field studies under comparable conditions. Must follow IPCC 2019 Refinement guidance (Ch 11, §11.2.1.1³). Subject to a moderate uncertainty discount.

Method 3: Biogeochemical Model-Based Emission Factors. Validated biogeochemical models (e.g., DNDC, DayCent) capable of simulating soil N₂O fluxes. Requirements:

• Model must be published in peer-reviewed literature.
• Calibrated using site-specific or regionally representative input data (soil texture, SOC, climate, crop type, nitrogen management).
• Validated against independent field measurements with predictions within ±30% of observed values using at least three independent datasets.
• Calibration and validation must conform to requirements for biogeochemical models as described in the Improved Soils Management Protocol and the intervention Module the project is crediting removals against,
• All model details must be documented in the PDD.

Subject to the smallest uncertainty discount where fully validated. Where all validation requirements for Method 3 are not fully met, Isometric may require the Method 2 discount.

The emission factor for diesel combustion ($EF_{diesel}$) must be expressed in kg CO₂e per litre, inclusive of direct fossil CO₂, CH₄, and N₂O from combustion. Biogenic CO₂ from the combustion of biofuel components is treated as carbon-neutral, consistent with IPCC GHG inventory conventions. CH₄ and N₂O are included regardless of fuel origin, as these are produced by the combustion process itself.

The emission factor for 100% petroleum diesel is 2.78 kg CO₂e per litre (comprising 2.70 kg CO₂ + 0.01 kg CO₂e from CH₄ + 0.07 kg CO₂e from N₂O), based on EPA GHG Emission Factors Hub (2025), Tables 2 and 5, using AR6 GWPs.

Where the baseline tillage operations used biodiesel blends, renewable diesel (HVO/HEFA), or other alternative diesel fuels, the Project Proponent must use a fuel-type-specific emission factor. The emission factor for a blended fuel is calculated as:

$$EF_{blend} = ((1 - x) \times 2.78) + (x \times EF_{bio})$$

(Equation 6)

Where:

• $x$ is the biofuel fraction (by volume)
• $EF_{bio}$ is the CO₂e emission factor for the biofuel component: 0.13 kg CO₂e/L for biodiesel (FAME) or 0.09 kg CO₂e/L for renewable diesel (HVO/HEFA).

Using a petroleum diesel emission factor when the actual baseline fuel contained biofuel results in overcrediting; the baseline emissions are overstated, inflating the credited reduction. To prevent this, fuel-type documentation is mandatory for projects claiming diesel reduction credits (see Section 10.2.2).

The petroleum diesel factor (2.78 kg CO₂e/L) may only be used where the Project Proponent provides documented evidence that baseline fuel was 100% petroleum diesel.

Where baseline fuel records are unavailable or the fuel type cannot be determined, diesel reduction credits may not be claimed.

Fuel consumption rates ($FC_{p,g}$) for each stratum must be determined using one of the following, in order of preference:

Approach A: Direct Measurement. On-farm records, fuel gauges, or GPS-linked monitoring. Records must cover at least one full season of baseline operations.

Approach B: Equipment-Specific Published Estimates. Published data for the specific equipment type, draft requirement, and soil conditions (e.g., ASABE Standards D497). Must specify implement type, working width, working depth, soil texture, and tractor power class.

Approach C: Default Estimates. Where neither Approach A nor Approach B data are available, the Project Proponent may use the following default fuel consumption values per pass (Table 2). Where multiple peer-reviewed estimates are available for an operation, the most conservative (lowest) value must be used to avoid overstating baseline diesel consumption and the resulting reduction credits.

Table 2: Tillage Diesel Fuel Use Default Estimates

The default values draw from two sources: Filipović et al. (2010), a peer-reviewed four-year instrumented field study on silty loam in a corn-wheat rotation; and Helsel, Grisso, and Grubinger, a US extension publication based on field data for corn production systems. Where the two sources diverge (notably chisel ploughing, disc harrowing, and field cultivation), the lower value is adopted as the conservative default. This reflects the principle that default estimates should not overstate baseline diesel consumption, as overstated baselines would inflate reduction credits.

Values will vary materially by soil type, working depth, tractor power class, and equipment condition. Where local conditions differ from the study conditions, Approach A or B must be used. Method C is subject to the largest diesel uncertainty discount.

The overall emissions in the project scenario during a given reporting period is calculated as:

$$CO_2e_{Project,RP} = CO_2e_{P,N_2O,RP} + CO_2e_{P,Diesel,RP}$$

(Equation 7)

Where:

• $CO_2e_{Project,RP}$ are the total project emissions associated with the relevant activities under this module for a given reporting period in tonnes CO₂e
• $CO_2e_{P,N2O,RP}$ are the project emissions due to fertilizer application for a given reporting period in tonnes CO₂e
• $CO_2e_{P,N2O,RP}$ are the project emissions due to tillage for a given reporting period in tonnes CO₂e

The project scenario N₂O emissions for a given reporting period are calculated as:

$$CO_2e_{P,N_2O,RP} = \sum\limits_g \left( Q_{N,P,g} \times A_g \times EF_{N_2O,g} \times \frac{44}{28} \times 10^{-3} \times GWP_{N_2O} \right)$$

(Equation 7)

Where:

• $Q_{N,P,g}$ is the project-scenario nitrogen application rate, verified through monitoring (Section 10). The same EF method must be applied to both baseline and project scenarios within a stratum.

The remaining variables are the same as used for Equation 4 in the determination of the pre-project emissions.

The project scenario emissions from tillage for a given reporting period are calculated as:

$$CO_2e_{P,Diesel,RP} = \sum\limits_g \left( \sum\limits_p \left( N_{passes,P,p,g} \times FC_{p,g} \right) \times A_g \times EF_{diesel} \times 10^{-3} \right)$$

(Equation 8)

Where the project involves no-tillage, $N_{passes,P,p,g}$ is zero for the project operations, but no-till planting fuel consumption must still be accounted for. The remaining variables follow the definitions set in Equation 5.

The uncertainty discount for each reductions component must use the value for the corresponding method for the emissions factor determination as described in Section 9.3. Uncertainty discounts are included in keeping with principles of conservatism and in recognition of the inherent uncertainties of crediting reductions.

The overall uncertainty is determined by weighting the relative contributions of the two reduction mechanisms:

$$D_{uncertainty} = \frac{D_{N_2O} \times CO_2e_{Red,N_2O,Gross} + D_{Diesel} \times CO_2e_{Red,Diesel,Gross}}{CO_2e_{Red,N_2O,Gross} + CO_2e_{Red,Diesel,Gross}}$$

(Equation 9)

Where a Project credits only one practice category, the applicable single-practice discount applies.

All emissions accounting requirements of the Improved Soil Management Protocol, the GHG Accounting Module v1.1, and the Energy Use Accounting Module v1.3 apply to the quantification of reductions under this Module.

Monitoring must be sufficient to enable independent verification of all parameters used in the net reduction calculation (Section 9 and the leakage assessment (Section 4.1.1.1).

For each enrolled field, the following must be documented each Reporting Period: type and quantity of synthetic nitrogen applied (kg N/ha per application event), timing, method of application, and where nitrogen-fixing cover crops are used evidence of establishment and termination. Field-level records are required; project-level averages are not acceptable.

For each enrolled field: tillage operations performed (type, passes, dates), equipment used, and confirmation of the project tillage regime. Remote sensing may corroborate but is not sufficient as sole evidence. For no-till transitions, positive evidence of no-till planting must be provided.

Report $Q_{N,P,g}$ for each stratum and Reporting Period in kg N/ha, disaggregated by product and timing. Organic nitrogen inputs must also be reported for complete accounting. Accuracy must be verified through purchase record reconciliation, precision agriculture maps, or independent agronomist review.

Report data sufficient to support Section 9.2.2 and Section 9.4.2, following the documentation requirements corresponding to the selected approach (A, B, or C) in Section 9.3.2.

Method A based on direct measurement as detailed in Section 9.3.2 is the preferred method which produces the lowest discount. On-farm records, data from fuel gauges, or GPS-linked monitoring are viable data sources for the continued monitoring of fuel consumption data. Records must cover at least one full season of baseline operations. Without direct measurement per one of these sources, equipment specific estimates (Method B) or literature estimates (Method C, Table 2) may be used with respectively higher discounts to estimate the diesel fuel consumption.

Documentation of fuel type is a mandatory prerequisite for crediting diesel reductions under Section 4.1.2. The Project Proponent must disclose the fuel type and blend used in both baseline and project-scenario tillage operations. Fuel type must be reported as one of: petroleum diesel (B0), biodiesel blend (specifying blend percentage, e.g., B5, B20), biodiesel (B100/FAME), renewable diesel blend (specifying blend percentage), or renewable diesel (R100/HVO).

Acceptable evidence of fuel type includes fuel purchase invoices identifying the product, supplier blend certifications, fuel delivery records, and documentation of applicable state or regional blend mandates during the baseline period.

Where a state or regional mandate requires a minimum biofuel blend and the project area falls within that jurisdiction, the VVB must verify that the declared baseline fuel type is consistent with the applicable mandate. A claim of petroleum-only fuel use in a jurisdiction with an active biofuel mandate requires additional evidence demonstrating that the mandate did not apply to the project's fuel supply (e.g., off-road diesel exemption documentation, direct supplier confirmation of petroleum-only product).

For all Projects crediting fertilizer reductions, report for each Reporting Period:

• Project-level yield ($Y_{Project,RP}$): area-weighted average across enrolled fields, calculated from field-level data.
• Field-level yield: for each field and commodity. Must be available for verification.
• Regional average yield ($Y_{Regional,RP}$): from official agricultural statistics. Document source, scope, and vintage.
• Baseline yield data: covering the full baseline period (5 years).

Yields must be reported and assessed separately for each commodity. Cross-commodity aggregation is not permitted.

For either fertilizer application or tillage using Method 2: confirm at each Reporting Period that the EF remains representative; update if better EF is published in literature.

For either fertilizer application or tillage using Method 3: update model inputs each Reporting Period; compare outputs against available field observations; recalibrate or revert to a lower-tier method if divergence exceeds 30%.

The diesel EF ($EF_{diesel}$) must be reviewed at each Crediting Period renewal and updated if revised by the IPCC or national inventory authority.

The Project Proponent must prepare a Monitoring Plan as part of the PDD, in accordance with the monitoring requirements of the Improved Soil Management Protocol. The plan must specify parameters, methods, frequency, responsible parties, data management, QA/QC procedures, and approaches to missing data.

All monitoring data must be retained for at least two years beyond the end of the Crediting Period.

1. Forster, P. et al. (2021). The Earth's Energy Budget, Climate Feedbacks, and Climate Sensitivity. In: Climate Change 2021: The Physical Science Basis. IPCC AR6 WGI. Table 7.15. ↩

2. IPCC (2019). 2019 Refinement to the 2006 IPCC Guidelines, Vol 4, Ch 11 Table 11.1. ↩

3. IPCC (2019). 2019 Refinement to the 2006 IPCC Guidelines, Vol 4, Ch 11 Table 11.1 ↩

4. Filipović, D., Košutić, S., and Gospodarić, Z. (2010). Comparison of tillage systems according to fuel consumption. Energy, 35(1), 221–228. ++https://doi.org/10.1016/j.energy.2009.09.020++. Values from Table 3: measured fuel consumption (L ha⁻¹) for individual tillage implements over four experimental years (1996–2000) on Albic Luvisol (silty loam), corn–winter wheat rotation, using a 92 kW four-wheel-drive tractor. ↩

5. McLaughlin, N.B., Drury, C.F., Reynolds, W.D., Yang, X.M., Li, Y.X., Welacky, T.W., and Stewart, G. (2008). Energy inputs for conservation and conventional primary tillage implements in a clay loam soil. Transactions of the ASABE, 51(4), 1153–1163. Mouldboard plough fuel consumption measured at 21.6 L ha⁻¹ on Brookston clay loam over four years (2002–2005). ↩