> For the complete documentation index, see [llms.txt](https://swatplus.gitbook.io/io-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://swatplus.gitbook.io/io-docs/swat+-output-files/carbon.md).

# Carbon

### Carbon-specific Outputs

To generate and view carbon-specific outputs in SWAT+, "hru\_cb" and "hru\_cb\_vars" need to be added to the print.prt file, in addition to the other desired outputs.

<table><thead><tr><th width="173.5283203125">Output Commands</th><th width="480.2137451171875">Description</th><th>Output Type</th></tr></thead><tbody><tr><td><a href="#output-files-generated-by-hru_cb">hru_cb</a></td><td>This command generates HRU-specific output files for total and sequestered SOC stock; amount of C, N, and P in litter, microbial, slow, and passive pools; fluxes of C, N, and P among pools, including flux-associated CO2 emission; amount of C in above and below ground live biomass, including plant parts; beginning and ending values for soils.sol parameters, including carbon; output optionally at end of day, end of month, end of year, and/or average annual; output also optionally by soil hydrology layer.</td><td>txt and/or csv</td></tr><tr><td><a href="#output-files-generated-by-hru_cb_vars">hru_cb_vars</a></td><td>This command generates more detailed carbon-balance related output, primarily for diagnostic purposes.  Includes output for tillage, soil water, temperature, oxygen factors impacting residue, litter, microbial, slow, and passive pool decomposition; fractions of flux allocated to CO2 emission and among pools; N:C ratios impacting microbial capacity to decompose; C, N transformation potentials of each pool; output optionally at end of day, end of month, end of year, and/or average annual; output also optionally by soil hydrology layer.</td><td>txt and/or csv</td></tr></tbody></table>