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Emission Reductions in Rice Management Systems

Voluntary Emission Reductions in Rice Management Systems

The American Carbon Registry (ACR) approved methodology Voluntary Emission Reductions in Rice Management Systems 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.

 

Projects using this methodology must comply with all requirements of the ACR Standard, submit a GHG Project Plan for certification by ACR, and secure independent validation and verification by an ACR-approved third-party verifier.

 

Approved Methodology Documents

  • DNDC Model Zip File: Save this in a root directory such as C:\. Then using a file compression program such as WinZip, right-click on the DNDC.zip file and choose “Extract to here.” This will create a folder C:\DNDC, with several subfolders as well as the DNDC95.exe file. Double-click this .exe file to launch DNDC. You will also see a User Guide file called GuideDNDC95.pdf; see page 10 of this guide for installation instructions.

 

Methodology Approval Process Documentation

  • ACR held a public comment webinar on July 16, 2013, "ACR Methodology for Emissions Reductions in Rice Management Systems—California and Mid-South Modules.” Please click here for the webinar presentation slides and please click here for the webinar recording.
  • Public Comments: None for California
  • Public Comments: None for Mid-South