What is Active Carbon?
Photo Credit: Jeff Vanuga, USDA-NRCS
A small portion of the total organic matter pool with a rapid turnover rate, indicating that it’s available to microbial decomposers. This portion of organic matter often responds more quickly and significantly to changes in agronomic management and is more closely correlated to crop productivity, than total soil organic matter. It can be measured in a variety of ways, including permanganate oxidizable C, mineralizable C, and water-extractable C. See soil organic matter and total organic carbon for more information.
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| Title | Source | Resource type and Date | Short Summary / Preview |
|---|---|---|---|
| Active Carbon | Soil Health Nexus | How-to Video
May 2019 |
Amanda Wolfgeher of the University of Missouri provides an overview of how to conduct an active carbon demonstration. |
| How to use Haney Tests | University of Minnesota | Archived Webinar
Oct 2019 |
A 1-hour webinar from UMN Extension describing active C and active N pools measured in the Haney test, as well as comparisons of fertilizer recommendations from Haney and standard soil tests. |
| How to Understand and Interpret Soil Health Tests | Purdue University | Extension Fact Sheet
Jun 2018 |
Description of commercially available soil health tests covering a range of active C tests, with tips for sampling and interpretation. |
| Soil Quality Indicators: Chemical Indicators and Soil Functions | USDA | NRCS Fact Sheet
Feb 2015 |
Different chemical indicators widely used are related to the respective basic functions they measure. |
| Soil Quality Indicators: Reactive Carbon | USDA | NRCS Fact Sheet
Jan 2014 |
Fact Sheet. Soil organic matter (SOM) contains C compounds with different levels of degradability, from very easily decomposable to extremely resistant (recalcitrant) to decomposition. |
| Title | Source | Resource type and date | Short Summary |
|---|---|---|---|
| Active Carbon | Cornell University | Extension Fact Sheet
Not Dated |
Active carbon is an indicator of the small portion of soil organic matter that can serve as a readily available food and energy source for the soil microbial community, thus helping to maintain a healthy soil food web. |
| Title | Source | Resource type and Date | Short Summary |
|---|---|---|---|
| The Sanborn Field Experiment: Implications for Long-Term Soil Organic Carbon Levels | American Society of Agronomy | Peer-Reviewed Publication
Jan 2011 |
It appears that an equilibrium level of SOC for some cropping systems takes about 30 to 40 yr to develop. Initial active carbon (AC) content assessment as a proxy for soil quality shows greater AC with manure and higher input management systems. The AC had a wide seasonal flux within a growing season as a function of temperature and moisture fluxes on microbial activity. |
| Comparison of Permanganate-Oxidizable Carbon and Mineralizable Carbon for Assessment of Organic Matter Stabilization and Mineralization | Soil Science Society of America Journal | Peer-Reviewed Publication
Sep 2016 |
Analyzes Pox-C and Mineralizable C on a range of long-term sites and compares them. |
| Conceptualizing soil organic matter into particulate and mineral‐associated forms to address global change in the 21st century | Global Change Biology | Peer-Reviewed Publication
Oct 2019 |
This paper suggests conceptualizing soil organic matter as particulate, or large and relatively un-decomposed, versus mineral-associated, or sorbed to silt and clay surfaces. It provides good background on current understandings of soil organic matter turnover and protection. |
| Persistence of soil organic matter as an ecosystem property | Nature: International Journal of Science | Peer-Reviewed Publication
Oct 2011 |
This paper describes the difference between concepts of humification and more modern concepts of soil organic matter storage, describing physical, biological and chemical means of protection. |
Last reviewed October 22, 2019