Cover crops have emerged as a viable solution to improve soil health, according to a recent study.
Cover crops are plants strategically grown to prevent erosion and enhance soil health. They are planted after the main harvest and are terminated before the subsequent cash crop is planted. Deepak Joshi, a Ph.D. graduate from South Dakota State University, conducted research to assess the impact of cover crops on soil organic carbon and greenhouse gas emissions in a corn cropping system.
While previous cover crop studies yielded mixed results, Joshi's comprehensive meta-analysis of 61 studies focused on corn cropping systems demonstrated a consistent benefit. The analysis revealed that cover crops increase soil organic carbon by 7.3%, indicating improved soil quality. By sequestering carbon dioxide from the atmosphere, cover crops contribute to mitigating climate change and enhancing soil health.
Joshi's research also demonstrated that current corn fields with cover crops have a soil organic carbon sequestration rate of 0.8 Mg. Scaling up cover crop adoption across all U.S. corn fields could result in an annual sequestration of 29.12 million Mg SOC, equivalent to 107 million metric tons of carbon dioxide. This sequestration volume is comparable to the greenhouse gas emissions from nearly 247.5 million barrels of oil or 23.8 million gasoline-powered vehicles driven for a year.
Additionally, the study found that rye cover crops reduced nitrous oxide (N2O) emissions during growth stages but increased emissions during decomposition. However, when considering both growth phases, cover crops had no significant effect on greenhouse gas emissions. Instead, cover crops improved soil health by enhancing soil microorganisms, moisture retention, and carbon content. Moreover, adopting cover crops increased corn yield by 23%, benefiting subsequent harvest seasons.
Although cover crop adoption rates have historically been low in the Upper Midwest, recent years have seen an increase in understanding the proven benefits, leading to a rise in adoption rates among farmers.
Deepak Joshi's exceptional research earned him the distinction of being named the recipient of the Distinguished Dissertation by the SDSU Graduate School. The study was published in the academic journal Agronomy Journal and received funding from various organizations, including the South Dakota Corn Utilization Council, USDA-NRCS, South Dakota State University Experiment Station, and the U.S. Department of Energy.
Hyperlink to the study: https://acsess.onlinelibrary.wiley.com/doi/10.1002/agj2.21340
Photo Credit: gettyimages-mvburling
Categories: South Dakota, Crops, Corn, Education, Energy, Harvesting