Version: 1.0

Published: March 29, 2023

INACTIVE: Rice Management Systems

The American Carbon Registry (ACR) methodology Emission Reductions in Rice Management Systems is is inactive and ineligible for crediting projects on ACR. ACR has determined that the methodology requires updates to measurement, monitoring, reporting and verification requirements to be consistent with the current version of the ACR Standard.

Methodology History

The methodology is applicable to Agricultural Land Management (ALM) project activities that involve a change in rice cultivation practices. The methodology was developed by Terra Global Capital LLC with support from Applied Geosolutions LLC, the Environmental Defense Fund and the California Rice Commission.
Parent Methodology

The methodology is modular in structure, lending itself to applicability in rice-growing regions around the world. The parent methodology provides definitions, applicability criteria, project boundary definition, baseline and additionality requirements, quantification methods, monitoring and verification requirements, and uncertainty calculations for all modules. The methodology defines Rice-Growing Regions, geographic regions in which the climate and rice management practices are relatively homogeneous, and over which the DNDC model (the main quantification tool in this methodology) is calibrated and validated.

California Regional Calibration Module

Approved simultaneously with the parent methodology is a regional calibration module for California. Eligible activities in California include (1) removal of rice straw from the field after harvest, (2) replacing water seeding with dry seeding, and (3) early drainage at the end of the growing season. Project Proponents who implement practices that increase Nitrogen use efficiency concurrently with these practices can combine this methodology with an ACR methodology for nitrous oxide emissions from fertilizer management in order to receive credits from reducing nitrous oxide emissions in addition to methane and/or carbon dioxide.

Mid-South Regional Calibration Module

The regional calibration module for the Mid-South applies to two U.S. rice-growing regions: 1) the Mississippi River Delta in Arkansas, Mississippi and Missouri, and 2) the Gulf Coast area in Louisiana. The Gulf Coast area in Texas may be added at a later date.

Eligible activities under the Mid-South module include: 1) removal of rice straw from the field after harvest, 2) early drainage at the end of the growing season, 3) intermittent flooding during the growing season, and 4) increased water and/or energy use efficiency, achieved through measures including but not limited to: convert contour levees to precision or zero grade; use of side inlet/poly piping systems; use of more efficient diesel pumps; switch from diesel to electric pumps; use of soil moisture sensors to tailor flood to water needs. Project Proponents who implement practices that increase Nitrogen use efficiency concurrently with these practices can combine this methodology with an ACR methodology for nitrous oxide emissions from fertilizer management in order to receive credits from reducing nitrous oxide emissions in addition to methane and/or carbon dioxide.

Structural Uncertainty Deduction Factors

Projects must apply an uncertainty deduction factor to account for model structural uncertainty and ensure conservative crediting. The structural uncertainty represents the uncertainty inherent in the DNDC model and is set using independent validation data (directly measured daily methane fluxes on benchmark sites) available at the time of methodology publication. Additional data will become available in the future, allowing the structural uncertainty deduction factors to be updated. In addition, as more fields are registered, structural uncertainty should decline, so the structural uncertainty deduction depends on the number of fields in all projects registered on ACR. Project proponents must always use the most recent version of structural uncertainty deduction factors.

DNDC Model

Baseline and project emissions are quantified using the Denitrification – Decomposition (DNDC) model. Please download the version of DNDC included below, which has been specifically calibrated for rice projects. Other versions (e.g. from the UNH website) are not to be used.

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INACTIVE: Rice Management Systems

Version 1.0

Previously approved versions

Process Documentation