Dynamic Stability of Soil Carbon: Reassessing the “Permanence” of Soil Carbon Sequestration

Enhancing soil organic matter in agricultural soils has the potential to contribute to climate mitigation while also promoting soil health and resilience. However, soil carbon sequestration projects are rare in carbon markets. 

One concern surrounding soil carbon is uncertainty regarding the permanence of newly sequestered soil carbon. This scientific uncertainty is exacerbated by differences in terminology used by scientists and policymakers that impedes the integration of new scientific findings regarding soil carbon longevity into evidence-based policies. 

A team from the University of California, Davis and The Nature Conservancy recently studied the lifespan of soil carbon and how the language used to describe it is differently understood in the scientific and policy sectors. They determined that recent scientific findings that have bearing on soil carbon lifespan are not part of discussions surrounding carbon policy; conversely, policymaker concerns are not clearly addressed by scientific research. 

From a policy perspective, soil carbon is generally assumed to be a vulnerable pool that is at risk of being quickly lost via microbial degradation or other avenues of physical loss if soil-carbon-building practices are not maintained indefinitely. This assumption has been challenged by recent scientific advances. 

The team, whose findings were published in Frontiers in Environmental Science, argues that soil carbon longevity can best be understood as resulting from continual movement and transformation of organic compounds throughout the soil matrix. This definition, however, is directly at odds with how soil carbon longevity is represented in current policies. 

Given current interest in new policies to promote soil carbon sequestration activities, resolving these definitions is critical. 

How might this affect growers? Quantification — and drawing the proper conclusion from data — is difficult in even the simplest of human endeavors. In baseball, for example, the relative straightforwardness of batting average and earned run average have evolved into a dizzying array of statistics that have, arguably, made the game more efficient but less fun to watch.The challenges involved in analyzing something as complex as soil health are infinitely more complex — and consequential. As this report highlights, we are just beginning to be able to understand what happens to carbon in the soil profile. Developing a single metric to assess soil health — from the farmer’s perspective — is something that will likely never happen. Simplifying the science for the sake of policymaking may be possible, though. But we’re not there yet. Farmers should proceed with caution when engaging in the emerging soil carbon markets.

Less Air Pollution Leads to Higher Crop Yields

Usually, increasing agricultural productivity depends on adding something, such as fertilizer or water. A new Stanford University-led study reveals that removing one thing in particular — a common air pollutant — could lead to dramatic gains in crop yields. 

The analysis, published in Science Advances, uses satellite images to reveal for the first time how nitrogen oxides — gases found in car exhaust and industrial emissions — affect crop productivity. 

Nitrogen oxides, or NO_x, are among the most widely emitted pollutants in the world. These gases can directly damage crop cells and can indirectly affect them through their role as precursors to the formation of ozone, an airborne toxin known to reduce crop yields.

The research team combined satellite measures of crop greenness and nitrogen dioxide levels for 2018-2020. Nitrogen dioxide is the primary form of NO_x and a good measure of total NO_x. Although NO_x is invisible to humans, nitrogen dioxide has a distinct interaction with ultraviolet light that has enabled satellite measurements of the gas at a much higher spatial and temporal resolution than for any other air pollutant.

Based on their observations, the researchers estimated that reducing NO_x emissions by about half in each region would improve yields by about 25 percent for winter crops and 15 percent for summer crops in China, nearly 10 percent for both winter and summer crops in Western Europe, and roughly 8 percent for summer crops and 6 percent for winter crops in India. North and South America generally had the lowest NO_x exposures. Overall, the effects seemed most negative in seasons and locations where NO_x likely drives ozone formation.

Actions that would reduce NO_x are the same types of changes that would slow climate change and improve air quality. 

Previous research by several members of the research team estimated that reductions in ozone, particulate matter, nitrogen dioxide, and sulfur dioxide between 1999 and 2019 contributed to about 20 percent of the increase in U.S. corn and soybean yield gains during that period — an amount worth about $5 billion per year.

Future analysis could incorporate other satellite observations, including photosynthetic activity measured through solar-induced fluorescence, to better understand nitrogen dioxide’s effects on crops’ varying degrees of sensitivity to the gas throughout the growing season.

Why does this report matter to farmers? While to some people, climate change can still seem abstract, far away and overly doom-and-gloomy … no one like air pollution. It’s a cause pretty much everyone can get behind, to some degree or another, because everyone can see and feel the effects of it every day. And great strides have been made in this area in the U.S. over the past several decades. Our air quality has improved remarkably. In 1970 there were over 26 million tons of NOx emitted in the U.S.; by 2021 there were only 7.6. This study has important implications for increasing yield worldwide. Reducing nitrogen oxides would surely have just as important an effect for regenerative growers as for conventional ones.Perhaps the best part of this finding is that it identifies a potential win-win: an agricultural policy — reducing air pollution — that almost everyone can get behind.

The Dutch Farm Crisis: Balancing Farmers’ Livelihoods with Environmental Concerns

A conflict between Dutch farmers and environmentalists has grown to the point that it has garnered worldwide media attention. At the heart of the dispute is the Dutch government’s proposal to cut nitrogen emissions by 50 percent by 2030 that will almost certainly put a significant number of the country’s livestock farmers out of business. 

The issue is of great concern for more Dutch citizens than its farmers alone; the country’s highest court has blocked construction permits for housing and business facilities — at a time when the country faces a severe housing shortage — until an agreement is reached, because the construction industry also contributes to nitrogen emissions. 

The Netherlands is the world’s second-largest exporter of agricultural products after the United States, even though it is only twice the area of Massachusetts. There are 30,000 livestock farms, and the livestock density is the highest in the world. While Dutch agriculture is incredibly efficient, and technological advances are improving manure management and thus nitrogen efficiency, both sides in the dispute acknowledge that there’s no way all 30,000 farms will be able to stay in business via improvements in efficiencies alone. 

The details of the situation are numerous and important for anyone seeking to espouse an opinion on it; readers are urged to consult many and varied media reports. 

What might this mean for the future of American livestock farmers? Finding a balance between the needs of food production and the similar necessity of protecting the environment is exceedingly difficult. On the one hand, it’s easy for many farmers and consumers to reject out-of-hand the arguments of environmentalists as soon as they say that we all need to exchange real meat for plant- and cell-based alternatives (or, even worse, insects). Environmentalists can’t be faulted, though, for likewise disregarding the opinions of conventional farmers who seem to value their individual livelihoods over the environment, which is shared by many.Hopefully this story will motivate U.S. farmers to adopt regenerative growing practices, which are far less environmentally damaging than conventional farming, in order to avoid a costly showdown in the future. And a lesson for policymakers is to start implementing changes like those proposed in the Netherlands gradually, with a long-term goal in mind, in order to ease the transition to ecological farming methods.There’s reason to be very confident that farmers will realize the promise of regenerative agriculture and adopt it on their own; on the prospect of lawmakers, in our current political culture, designing wise, far-sighted policies … there’s less cause to be optimistic.

Artificial Photosynthesis Can Produce Food without Sunshine

Photosynthesis turns water, carbon dioxide and the energy from sunlight into plant biomass and the foods we eat. This process, however, is very inefficient, with only about 1 percent of the energy found in sunlight ending up in the plant. Scientists at UC Riverside and the University of Delaware have found a way to bypass the need for biological photosynthesis altogether and to create food independent of sunlight by using artificial photosynthesis.

The research, published in Nature Food, uses a two-step electrocatalytic process to convert carbon dioxide, electricity and water into acetate — the form of the main component of vinegar. Food-producing organisms then consume acetate in the dark to grow. Combined with solar panels to generate the electricity to power the electrocatalysis, this hybrid organic-inorganic system could increase the conversion efficiency of sunlight into food — up to 18 times more efficiently for some foods.

“With our approach, we sought to identify a new way of producing food that could break through the limits normally imposed by biological photosynthesis,” said corresponding author Robert Jinkerson, a UC Riverside assistant professor of chemical and environmental engineering.

In order to integrate all the components of the system, the output of the electrolyzer was optimized to support the growth of food-producing organisms. Electrolyzers are devices that use electricity to convert raw materials like carbon dioxide into useful molecules and products. The amount of acetate produced was increased while the amount of salt used was decreased, resulting in the highest levels of acetate ever produced in an electrolyzer to date.

“Using a state-of-the-art two-step tandem CO₂ electrolysis setup developed in our laboratory, we were able to achieve a high selectivity towards acetate that cannot be accessed through conventional CO₂ electrolysis routes,” said corresponding author Feng Jiao of the University of Delaware.

Experiments showed that a wide range of food-producing organisms can be grown in the dark directly on the acetate-rich electrolyzer output, including green algae, yeast and fungal mycelium that produce mushrooms. Producing algae with this technology is approximately fourfold more energy efficient than growing it photosynthetically. Yeast production is about 18-fold more energy efficient than how it is typically cultivated using sugar extracted from corn.

“We were able to grow food-producing organisms without any contributions from biological photosynthesis. Typically, these organisms are cultivated on sugars derived from plants or inputs derived from petroleum,” said Elizabeth Hann, a doctoral candidate in the Jinkerson Lab and co-lead author of the study. “This technology is a more efficient method of turning solar energy into food, as compared to food production that relies on biological photosynthesis.” 

The potential for employing this technology to grow crop plants was also investigated. Cowpea, tomato, tobacco, rice, canola and green pea were all able to utilize carbon from acetate when cultivated in the dark.

“We found that a wide range of crops could take the acetate we provided and build it into the major molecular building blocks an organism needs to grow and thrive. With some breeding and engineering that we are currently working on we might be able to grow crops with acetate as an extra energy source to boost crop yields,” said Marcus Harland-Dunaway, a doctoral candidate in the Jinkerson Lab and co-lead author of the study.

“Using artificial photosynthesis approaches to produce food could be a paradigm shift for how we feed people. By increasing the efficiency of food production, less land is needed, lessening the impact agriculture has on the environment. And for agriculture in non-traditional environments, like outer space, the increased energy efficiency could help feed more crew members with less [sic] inputs,” said Jinkerson.

This approach to food production was submitted to NASA’s Deep Space Food Challenge, where it was a Phase I winner. The Deep Space Food Challenge is an international competition where prizes are awarded to teams to create novel and game-changing food technologies that require minimal inputs and that maximize safe, nutritious and palatable food outputs for long-duration space missions.

What does this mean for agriculture? Liberating agriculture from dependence on the sun may strike one as thrilling or terrifying, depending on one’s perspective.While a scenario may exist in which technology like this would make sense — perhaps space travel — one has to wonder why, if there’s enough sunlight in a given area to produce acetate via electrolyzation, how is there not enough sunlight to grow a plant naturally? The electrolyzation process would have to take place elsewhere, but this becomes a problem in a space-constrained area like on a spacecraft.Overall, though, while adopting appropriate technologies is certainly a hallmark of regenerative agriculture, it seems wise to be generally skeptical of new ones — especially a technology offering to free us from the way plants have grown for the Earth’s entire history. While it is intriguing to consider the possibilities of these discoveries in light of space travel, responsible ways of growing food — the natural way — are already able to feed the entire planet.

Research Contract Gave Bayer Control of Neonics Study Methods, But University Researchers Claimed Full Credit

Bayer and Syngenta — companies that manufacture neonicotinoid insecticides — gave $301,671 to researchers at Iowa State University for a research project titled “Estimating the exposure to neonicotinoid residues in pollinator-attractive habitat adjacent to corn and soybean fields.”

Neonicotinoids have been demonstrated by a wide variety of studies to be toxic to bees and other pollinators. 

The studies that arose from the grant only acknowledged Bayer and Syngenta’s contribution of funds — not that the contract granted them influence over the methods of the study. The contract said that “Specific methods from Bayer will be utilized to extract samples of pollen, nectar, leaves, water, and soil from the field sites.” It also empowered a Bayer scientist to assist with the “design, conduct, and interpretation of the study.”

ISU says that such disclosure was not necessary because Bayer and Syngenta were not actually involved as much as was allowed in the contract.

Experts in research ethics have however deemed that ISU improperly allowed the companies to have too much influence over a study that was directly related to the products they sell. Investigate journalist Paul Thacker, who specializes in science research conflicts of interest, noted that “Bayer could have hired a contract research lab to do this exact kind of research, but then it would’ve been a Bayer study. But they didn’t want it to be a Bayer study.”

Erik Millstone, a professor emeritus from the University of Sussex who has studied corporate influence on science, added that the Bayer scientist who was allowed to design, conduct and interpret the study — per the contract — should have been declared an author in the published paper, but was not.

Thus far, the grant has resulted in two published studies. In one, published in 2022 in Agriculture, Ecosystems, and the Environment, various neonicotinoids found in cropland-adjacent soil and leaf tissue was found to be not at high enough levels to harm monarch butterfly larvae. The paper said that the authors had “no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.”

The documents that this information was based on were obtained by U.S. Right to Know through an Iowa Open Records Law request. Learn more at usrtk.org.

Should we be surprised about this? No. The obvious lack of integrity demonstrated in this incident is merely consistent with human nature and thus should not be surprising to anyone. The thing to keep in mind, though, is that the ethical violations occurred in this case both private and public sectors. I.e., it’s not only big business that is capable of corruption. Relying on government to reign in powerful agribusiness corporations simply puts the power in different corruptible hands. In fact, many would argue that it’s only because of complicity with government that businesses are able to become monopolistic.Separately, this is another reminder to prudently weigh every scientific study with a grain of salt. In this case, the undue financial interests (of Bayer and Syngenta) and professional interests (of the researchers) were exposed; how many other studies do we hang our hats on that are built on similarly shaky ground?