ERDC-CERL researchers find innovative ways to measure soil carbon

U.S. ARMY ENGINEER RESEARCH AND DEVELOPMENT CENTER
Published March 30, 2023
Researchers with the U.S. Army Engineer Research and Development Center use new technology to directly measure soil carbon on 5,000 acres of Fort Riley training lands.

Researchers with the U.S. Army Engineer Research and Development Center use new technology to directly measure soil carbon on 5,000 acres of Fort Riley training lands. This technology will replace the current method of measurement that requires soil cores to be collected and analyzed at a laboratory. (U.S. Army Corps of Engineers photo)

Researchers at the U.S. Army Engineer Research and Development Center (ERDC) are collaborating with Carbon Asset Solutions (CAS), a company that holds the license to a newly developed U.S. Department of Agriculture (USDA) soil scanning technology, to directly measure soil carbon on 5,000 acres of Fort Riley training lands. 

The scanning technology replaces the standard method of measurement that requires soil cores to be collected and analyzed at a laboratory. Due to the high cost of the current method, only a single 4-inch soil core is collected per acre for measurement, which represents less than 0.0002% of the total soil. This new technology now allows near real-time, non-destructive soil sampling with up to 100% coverage of the soil.

“Soil carbon measurement is important not only for carbon sequestration calculations, but increasing soil carbon also provides multiple ecosystem service benefits, including rooting depth, nutrient cycling, soil stabilization, water infiltration and drought tolerance,” said Ryan Busby, a research ecologist with the ERDC’s Construction Engineering Research Laboratory.

Busby chose Fort Riley as the initial validation spot for his study on DoD lands due to its dominance by prairie vegetation and Fort Riley training area managers’ interest in adopting scientific advancements. Prior to his research, the technology had only been used in agricultural fields and pastures.

 

“Many other installations have forests and shrublands, so I wanted to validate the technology in a landscape that wasn't too difficult for the initial scan,” said Busby.

Using the CAS prototype, the soil measurements taken at Fort Riley represent the largest single soil carbon survey ever conducted. The technology was developed by the USDA Agricultural Research Service's (ARS) National Soil Dynamics Laboratory and licensed to CAS. The data is being used to develop a carbon assessment for DoD lands.

The soil carbon pool is the most difficult to measure because it normally requires laboratory measurement. Trees can be measured in the forest using remote sensing to estimate carbon; however, soil samples must be removed and taken elsewhere for analysis, which only allows small volumes of soil to be measured. This results in low accuracy soil carbon estimates.

Busby is excited to see his hard work finally paying off after years of collaborating with the technology developers to demonstrate this technology.

 

“I originally worked with the technology developers at ARS to adapt it for DoD applications but could never get those efforts funded,” said Busby. “We originally focused on soil contaminant detection since the technology is not limited to carbon but can detect multiple elements in the soil. However, with growing interest in soil carbon, I have the chance to utilize this game-changing technology to make drastic improvements to how DoD measures and monitors soil carbon.”