Fact: Cleaner air leads to healthier bodies and lower medical costs.
Such benefits have long been touted by the American Lung Association, public health officials, nurses, doctors, respiratory therapists, environmental regulators, and others. But two scientists acting as smog detectives claim they now have evidence to prove that cleaner air also benefits the production of crops like corn and soybeans; two of the most common crops in the Midwest, including in Michigan and Ohio
In a recent study distributed by the Massachusetts Institute of Technology’s Sloan School of Management — MIT’s business school — Konstantinos Metaxoglou and Aaron Smith found that yields for corn and soybeans went up by an average of 2.5 percent and 1.6 percent, respectively, in 30 states between 2003 and 2011.
Ohio’s increase for corn yields during that eight-year stretch went up 5.3 percent, fourth for improvement behind Kentucky, West Virginia, and South Carolina. Ohio’s increase for soybean yields went up 2.9 percent during that time period, eighth behind South Carolina, Kentucky, Maryland, Alabama, Delaware, West Virginia, and New Jersey.
Michigan’s increase for corn yields went up 2.6 percent from 2003 to 2011, and its increase for soybeans went up 1.7 percent.
Mr. Metaxoglou, an associate economics professor at Carleton University in Ontario, is a visiting professor at MIT’s business school. Mr. Smith is the DeLoach Professor of Agricultural Economics at the University of California-Davis.
The two were curious what benefit plant fibers receive from cleaner air now.
The form of air pollution commonly known as smog has been on a gradual decline since the federal Clean Air Act was enacted in 1970 and updated in 1990. According to the U.S. Environmental Protection Agency, ground-level ozone — one of the six so-called “criteria” air pollutants the agency focuses on — is created when emissions of nitrogen oxides and volatile organic compounds react. That forms smog.
For purposes of their study, the two authors focused on nitrogen oxides emitted from coal-fired power plants, which have been on the decline for a number of reasons.
First, there are tighter air pollution controls than there were in 1970. More recently, though, America has been producing a lot more of its electricity from natural gas and renewable energy. Prices for both have fallen. The horizontal style of hydraulic fracturing, or “fracking” of shale in recent years has opened up previously inaccessible reserves of natural gas and oil worldwide.
The study focused on plant fibers, not soil health. It concludes there is a direct cause and effect between cleaner air and better yields, and that the possibility of simple coincidence was scientifically ruled out, Mr. Metaxoglou said in an interview with The Blade.
“If emissions keep going down, we know this is good for yields,” he said. “It’s the [ground-level] ozone particularly that affects yields. If we just look at air pollution on crop fields, 90 percent of any yield losses are attributed to air pollution.”
In their 91-page report, the authors state that air pollution “reduces crop yields by slowing down photosynthesis.”
Their study appeared in the American Journal of Agricultural Economics, a peer-reviewed journal published by Oxford University Press.
But there’s a downside for farmers: Better yields create surpluses. Prices fell for those two crops, prompting the authors to conclude “that these changes made consumers better off and farmers worse off.”
“I don’t think farmers can do much to avoid it,” Mr. Metaxoglou said.
The Blade contacted more than a dozen people in the agricultural industry and Ohio State University agriculture experts about the study. Only three offered any comments.
“It makes sense that plants, like humans, do better without pollution,” Joe Logan, Ohio Farmers Union president, said.
Ty Higgins, Ohio Farm Bureau Federation spokesman, said no one at that organization deals directly with agronomics or atmospheric science.
But he said he has been in meetings in which some agricultural experts now wonder if reductions of a different form of air pollution, sulfur dioxide, which is commonly called acid rain, has had an unintended consequence of pulling important concentrations of sulfur out of the soil. Farmers now find themselves spending money to restore the sulfur content of their land with more fertilizers.
Joe Nester, owner of Bryan-based Nester Ag, LLC, a past president of the Ohio Association of Independent Crop Consultants, past Board Chairman of the Ohio Certified Crop Advisers, and a Director with Brookside Laboratories, Inc., said the smog study “could go in the Comics section.”
“There is no way this has had any impact on crop yields,” he said. “They are reaching WAY out there on this.”
Mr. Nester said he could list “many, many reasons why crop yields have increased,” none of which would be as a result of smog levels lowered by the federal Clean Air Act.
“In fact, the Clean Air Act has cost farmers money,” he said. “They used to get a good amount of crop-required sulfate from acid rain. Now, they have to buy the sulfate.”
Mr. Nester also said sulfate is “somewhat of a natural fungicide.” Plant diseases, he said, increased once acid rain was reduced, prompting farmers to “spend significant dollars on fungicide.”
Mr. Metaxoglou stood by the results of the smog study, adding that it shows cleaner air is “very important for the economy.”
Perrysburg Township farmer Kris Swartz said he is "skeptical that we can attribute yield increases or decreases to any one particular factor when so many are involved in producing yield."
"Certainly genetics have played a large part in increasing yields over that time frame, but the weather and a host of biological factors have played a part as well," Mr. Swartz said.
First Published March 9, 2020, 11:00 a.m.