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Rapid Carbon Assessment (RaCA)

The Rapid Carbon Assessment (RaCA) was initiated by the USDA-NRCS Soil and Plant Science Division in 2010.

SOC stocks prepared using LUGR means attached to gSSURGO grid.

Quick Links
Methodology, Sampling, and Summary
Data Tables
Recommended Citation
More Data and Information


The Rapid Carbon Assessment (RaCA) was initiated by the USDA-NRCS Soil Science Division in 2010 with the following objectives:

  • To develop statistically reliable quantitative estimates of amounts and distribution of carbon stocks for U.S. soils under various land covers and to the extent possible, differing agricultural management.
  • To provide data to support model simulations of soil carbon change related to land use change, agricultural management, conservation practices, and climate change.
  • To provide a scientifically and statistically defensible inventory of soil carbon stocks for the U.S.

To accomplish these objectives, 144,833 samples were collected from the upper 1 meter of 32,084 soil profiles at 6,017 randomly selected locations for measurement of organic and inorganic carbon by visible and near infrared (VNIR) spectroscopy and bulk density by traditional methods. NRI sites were used as the basis for random selection of sample sites stratified by soil group within RaCA Region and land use/land cover (LULC) within soil group. Soil morphology and landscape characteristics were described at each site and limited vegetation and agricultural management information was collected from each location. Sample collection and analysis involved more than 300 soil scientists and assistance from 24 universities.

Methodology, Sampling, and Summary

Rapid Carbon Assessment Download (links to Box; Zip file is 336 MB)

Data Gathering Documentation

Data Tables

The files below are located in Box

  • RaCA samples (CSV; 41.1 MB)
  • RaCA general location (CSV; 145 KB)
    • Locations of each site have been degraded due to confidentiality and only reflect the general position of each site
  • RaCA SOC pedons (CSV; 796 KB)
  • RaCA data columns (CSV; 7 KB)
Effort has been made to provide accurate and complete information. However, we cannot guarantee that there will be no errors. It is the user’s responsibility to understand the prediction methods and uncertainties that are associated with this data. Neither the U.S. Government, USDA, NRCS, or NSSC assumes any legal liability for the accuracy, completeness, or usefulness of any information, product, or process disclosed herein.


Soil Organic Carbon Stocks


Rapid Carbon Assessment Regions.

RaCA Regions

RaCA Region 1 (2.53 MB)
RaCA Region 2 (2.61 MB)
RaCA Region 3 (3.07 MB)
RaCA Region 4 (2.58 MB)
RaCA Region 5 (4.14 MB)
RaCA Region 6 (3.05 MB)
RaCA Region 7 (4.04 MB)
RaCA Region 8 (2.67 MB)
RaCA Region 9 (3.21 MB)
RaCA Region 10 (3.1 MB)
RaCA Region 11 (3.3 MB)
RaCA Region 12 (2.48 MB)
RaCA Region 13 (3.38 MB)
RaCA Region 14 (2.78 MB)
RaCA Region 15 (2.36 MB)
RaCA Region 16 (3.23 MB)
RaCA Region 18 (3.26 MB)


University of Alaska, University of Arkansas – Fayetteville, University of Arkansas – Pine Bluff, Auburn University, Colorado State University, University of Florida, University of Hawaii, University of Idaho, Idaho State University, Louisiana State University, University of Missouri, University of Nebraska – Lincoln, University of Nevada – Reno, North Carolina State University, Oregon State, Penn State University, Purdue University, University of Rhode Island, University of Tennessee – Martin, Tennessee Tech University, Texas A&M (AgriLife), Tuskegee University, Utah State University, West Virginia University, University of Wisconsin, University of Wisconsin – Stevens Point

Recommended Citation

Soil Survey Staff. Rapid Carbon Assessment (RaCA) project. United States Department of Agriculture, Natural Resources Conservation Service. Available online. June 1, 2013 (FY2013 official release).

More Data and Information