How Much Carbon Can Be Stored and Will It Reduce Global Warming?
Carbon dioxide is released during the process of soil organic matter decomposition, and it is removed from the atmosphere when plants convert carbon dioxide to biomass via photosynthesis (Fig. 3). Because atmospheric carbon dioxide levels are increasing (Fig. 4), mostly due to combustion of fossil fuels, and because increased atmospheric levels of carbon dioxide are thought to contribute to global warming and climate change, there is interest in investigating whether agricultural systems could reduce carbon dioxide in the atmosphere through carbon sequestration in soil. Carbon sequestration occurs when the amount of carbon retained in soil organic matter from inputs of plant and root residues exceed the amount of carbon lost from organic matter decomposition. However, carbon sequestration in annual cropping systems of the USA Corn Belt has not generally been accepted as a viable means of storing carbon due to concerns about the longevity of such storage compared with carbon storage in
