SOCMA: Soil Organic Carbon in MA

Massachusetts now has statewide land cover-adjusted soil organic carbon (SOC) maps that support carbon-informed land use decisions.

Download the desktop GIS-ready layers below to view current SOC stocks and compare them with potential SOC under an optimal land cover scenario.

Last updated: January 2, 2026

What’s included

This download includes:

  • The SOCMA Final Report [PDF]
  • Landcover SOC Conversion Table [CSV]
  • Map Unit Landcover SOC Result Metadata [GPKG]
  • Readme GIS data Soil Organic Carbon SOCMA 251203 [PDF]
  • Desktop GIS-ready layers for:
    • Current SOC (estimated under existing land cover)
    • Potential SOC (estimated under optimal land cover)
    • Three depth intervals: 0–30 cm, 0–100 cm, and full soil profile

How to use the layers

In ArcGIS Pro / QGIS:

  1. Download and unzip the file
  2. Drag the layer file into your map, or use Add Data

Example view: current vs potential SOC outputs across three depths (Northampton oxbow region). Values shown in metric tons per acre.

About the dataset

These layers were developed for Land Cover-Adjusted Soil Organic Carbon Mapping for Massachusetts, funded by the Massachusetts Healthy Soils Initiative. The maps integrate USDA-NRCS SSURGO soils data with 2016 Massachusetts land cover to estimate SOC density at 1-meter resolution across the state.

Use notes and limitations

Please note:

  • These layers represent modeled estimates, not direct field measurements at each location.
  • The analysis uses SSURGO data collected across multiple decades combined with 2016 land cover, which introduces temporal uncertainty.
  • Conversion factors may not apply in every context (for example, wetlands are treated as a special case).

Contact

Questions or troubleshooting help: Contact Regenerative Design Group