Total organic matter is an important soil property that is routinely measured in standardized soil tests. However, total organic matter is not an ideal indicator of nutrient availability because the majority of this pool is not plant available and typically changes very slowly over time. Active organic matter is a small fraction of total organic matter (5 - 20%) but it’s role is incredibly important to crop nutrition as active organic matter nutrients are rapidly cycled and are taken up by crops for quick feeding.
Organic matter influences many soil properties due to the fact that roughly half of all organic matter is made up of carbon. Carbon is the backbone of life. It is the currency that plants and soil food webs use to cycle nutrients and energy through the soil. Because of the importance of organic matter, there is great interest in developing meaningful and affordable soil health tests for farmers. Our lab works with two tests that directly measure the active pool of organic matter: Active Carbon (Permanganate Oxidizable Carbon – POXC) and Soil Respiration (Mineralized carbon).
Learn more about soil health and active organic matter in soils here
Check out Ohio State Extension's Soil Health Signature Program: soilhealth.osu.edu