Simple soil carbon test arrives

Ohio State University researchers have developed a method for measuring soil quality that involves mixing the soil with a non-toxic solution and measuring active carbon content by matching the colour of the solution to a colour-coded chart. The work is in association with Ray Weil, a soil scientist with the University of Maryland.
Rafiq Islam, a soil and water specialist with Ohio State's South Centers at Piketon, said the simplified test would enable users to measure soil quality directly on site and make soil management practices based on the results.
"With this test anyone can monitor the quality of their soil right in the field and measure it over time based on what management practices they've applied," said Islam. "It's not meant to replace the commercial soil tests, but it's just another tool for farmers who can then conduct additional soil tests or consult professionals if they do have poor soil quality." Soil organic matter is a core indicator of soil quality, and soil quality is usually characterized by high levels of active carbon. Active carbon includes microbial biomass, amino acids, soluble carbon and soil carbohydrates. Any changes in the levels of active carbon changes the level of organic matter, resulting in either a degradation or improvement in soil quality.
"Most organic matter is not active," said Islam. "So acquiring results from a test that also accounts for inactive carbon is not a very accurate assessment of soil quality. We needed a test that separated the active carbon from the rest of the soil content."
The result is a method that can accurately identify active carbon in field and lab situations on soils around the world. Researchers were also able to test for active carbon between plowing and no-till production systems compared to methods that tested for total carbon content. They found that while neither system showed any significant difference in total carbon levels, the no-till system produced a higher active carbon content under the new testing method.
The researchers equate the test to soil pH kits. "It's simple and cost effective, requires no elaborate equipment and can be tested on a wide variety of soil types," said Wright.