Active carbon and respiration tests can be used to assess soil organic matter dynamics

April 23, 2017

By Vinayak Shedekar      A team of scientists led by Ohio State University examined the relationship between two rapid and affordable soils tests that measure the soil active organic matter – a fraction of soil organic matter that has a shorter turnover time and the main driver of soil biological activity and nutrient availability. The team collected more than 1000 soil samples from farmers’ fields and long-term cropping system trials across the United States and analyzed them for permanganate oxidizable carbon (aka ‘active carbon’) and soil respiration (aka ‘mineralizable carbon’). They found that the two soil tests are correlated but differentially affected by agricultural management practices. Active carbon measurements were more related with reduced tillage and compost/biochar additions – practices that are expected to promote organic matter sequestration or stabilization. Whereas measurements of soil respiration were more related with tillage, leguminous cover crops, and manure additions – practices that are expected to promote organic matter mineralization. Data from the study should provide a framework for assessment of organic matter dynamics (stabilization vs. mineralization) in farmers’ fields. (Their work was published in Soil Science Society of America Journal and featured in December 2016 Crops-Soils-Agronomy news magazine.)

Please visit Publications section for a link to the open access article. More soil related information is available on Resources page.