Ohio State University Extension (OSUE) in Piketon, Ohio, has a new active C kit for soil health testing that is more sensitive to small changes in active C than a traditional soil organic matter (SOM) test. It has a longer shelf life now because OSUE chemists made it acid-based rather than basic-based like the Cornell Active C test. OSUE says their test will work better in red dirt such as that found in the southeast U.S. than the older potassium permanganate test. It is available from Soil1.com. It can also be used to estimate N credits to reduce N fertilizer use.