A recently reported study on the Midwest Corn Belt determined that nearly one-third of this farmland has lost its carbon-rich topsoil. Soil organic matter, the carbon-based portion of the soil, is a critical component of healthy soil. The loss has been primarily from hilltops and ridgelines and is a consequence of tillage erosion from repeated plowing. The more deficient quality soil has contributed to an estimated 6% loss of crop yield and nearly $3 billion in losses for farmers across the Midwest each year. Additionally, the more loss of natural organic matter, the more artificial fertilizers that are required for crop growth.
Degraded soils can often be restored by switching from conventional agricultural practices to restoration or sustainable practices. One prime example is the use of cover crops. These plants can convert carbon dioxide into organic matter, which is associated with minerals in the soil. Here, the function is 2-fold: cover crops take in carbon dioxide from the atmosphere and restore soil productivity.
In 2020, about 10% of US greenhouse gas emissions (those contributing to climate change) came from agriculture. Methodologies are being developed to verify the sustainability of farming practices, to prove they are improving the ability of crops or pastures to transfer CO2 into the soil or reduce nitrous oxide and methane emissions. While this science and understanding are evolving, much of it takes advantage of satellite imaging and other high-tech approaches. The new carbon programs also benefit farmers financially since they can sell carbon credits – the metric tons of carbon taken up by their plants – to the private marketplace.
The bottom line is that there are methods to restore soil, which also can remove significant amounts of carbon dioxide from the atmosphere. Composting organic waste is another critical way to re-enrich the earth. The potential for soil restoration is enormous and promising and hopefully continues to be part of the future for agriculture and home gardening practices.
Julie Peller Ph.D. is an environmental chemist (Professor of Chemistry at Valparaiso University ) and she leads the Environmental Ministry at Nativity of Our Savior in Portage IN. Julie has been writing a weekly column for church bulletins for the past ~6 years called the Green Junction and is helping to move the call of Laudato Si to action forward. Her Research Interests are in Advanced oxidation for aqueous solutions, water quality analyses, emerging contaminants, air quality analyses, Lake Michigan shoreline challenges (Cladophora, water, and sediment contaminants), student and citizen participation in environmental work