Carbon Capture: Digest #2

The Ohio State University's Jackie Wilkins, and one of the original Co-PIs on the C-FARM project for the Lal Carbon Center, has been named one of Ohio's top 50 women leaders in 2023 by Women We Admire, an organization of the most accomplished women executives and leaders across the U.S. and Canada.

The dust storm tragedy on I-55 in central Illinois on May 1, 2023, a reminder of the Dust Bowl era of the 1930s, necessitates urgent policy intervention to replace plow tillage with Conservation Agriculture (CA) involving no-tillage with crop biomass mulch, cover cropping, and complex crop rotations. System-based CA has co-benefits including control of soil erosion by wind (dust storm) and water, low risks of nonpoint source pollution including algal bloom, adaptation and mitigation of climate change, reduced incidence of drought-flood syndrome, sustained productivity, high farm income, and improved soil health. The current farm bill already contains a Clean Water Act, Clean Air Act, and Growing Climate Solutions Act that can all be complemented and more effective with a healthy soil. The forthcoming farm bill should have provision to reward farmers for ecosystem services at a nominal rate, e.g., US$50 ac−1 yr−1 (~US$123.46 ha−1 y−1), through a proposed “Soil Health Act” to further CA as a solution to climate change and other environmental issues. Restoring soil health through CA is a win-win option and a major contribution to mitigating future climate extremes and food security.

Dr. Lal interviewed for Mongabay with Ramesh Menon. They discuss the imperative to care for the soil so that we may avoid food insecurity for millions. 

The term carbon (C) sequestration has not just become a buzzword but is something of a siren's call to scientific communicators and media outlets. Carbon sequestration is the removal of C from the atmosphere and the storage, for example, in soil. It has the potential to partially compensate for anthropogenic greenhouse gas emissions and is, therefore, an important piece in the global climate change mitigation puzzle. However, the term C sequestration is often used misleadingly and, while likely unintentional, can lead to the perpetuation of biased conclusions and exaggerated expectations about its contribution to climate change mitigation efforts. Soils have considerable potential to take up C but many are also in a state of continuous loss.

ABSTRACT The U.S. government is planning significant reductions in greenhouse gas emissions as part of their nationally determined contribution to the Paris Agreement. The plan includes a variety of activities, one of which is enhancing carbon sinks in soils through a climate-smart agriculture program. The nature of soil carbon along with market forces, cultural factors and other issues create challenges for a program in climate-smart agriculture. These challenges include quantification of soil carbon sequestration, targeting practice adoption that is additional to past adoption, and ensuring that emissions of other greenhouse gases do not increase with climate-smart practices. In addition, there are challenges associated with maintaining carbon storage in soils over a long-time horizon; and avoiding increases in greenhouse gas emissions on non-participating lands. We review and discuss options for addressing challenges with direct regulations, subsidies and tax incentives, carbon taxes, and carbon credit offsets. None of these policy interventions are likely to overcome all challenges, but there are ways to limit risks that challenges pose to each intervention. The ability of the U.S. government to limit or mitigate these risks through careful design of a climate-smart agriculture program will largely determine how much carbon is sequestered in soils, and associated contributions to their emissions reduction goal for the Paris Agreement. 

In recent years, there has been considerable progress in determining the soil properties that influence the structure of the soil microbiome. By contrast, the effects of microorganisms on their soil habitat have received less attention with most previous studies focusing on microbial contributions to soil carbon and nitrogen dynamics. However, soil microorganisms are not only involved in nutrient cycling and organic matter transformations but also alter the soil habitat through various biochemical and biophysical mechanisms. Such microbially mediated modifications of soil properties can have local impacts on microbiome assembly with pronounced ecological ramifications. In this Review, we describe the processes by which microorganisms modify the soil environment, considering soil physics, hydrology and chemistry.