How “Big Ag” Pollutes America’s Water, and Makes Money Doing It

Yves here. Among other things, this post illustrates how much inertia drives business behavior (and even small farmers are businesses). Many operations would rather stick with settled practices, even when as shown here, they result in waste, undue cost, and damage to critical resources, here water.

By Keith Schneider, a former New York Times national correspondent, and senior editor for Circle of Blue who has reported on the contest for energy, food, and water in the era of climate change from six continents. Originally co-published at the New Lede with Circle of Blue, and was made possible and also co-published by the Alicia Patterson Foundation

It’s been 33 years since an Iowa State University agronomist named Fred Blackmer thought he’d struck gold for Midwestern corn farmers. Using a fairly simple three-step method, Blackmer developed an analytical tool that could accurately tell farmers exactly how much fertilizer their fields needed to produce abundant harvests each season.

The analytics Blackmer perfected showed not only how much fertilizer the corn crops would need to meet production targets, but also exposed how much could be wasted. Blackmer ultimately determined that farmers were applying a staggering 500 million excess pounds of nitrogen each year, a practice that not only wasted farmers’ money but also wreaked havoc on the environment as the nitrogen not taken up by plants drained from farm fields to contaminate rivers, lakes, and streams.

Despite what Blacker saw as obvious benefits to producers, not to mention the environment, his method failed to gain significant traction in farm country. Farmer allegiance to the excessive fertilizing practices  pushed by the so-called “Big Ag” industry and aligned academic institutions left Blackmer’s common sense approach on a shelf gathering dust. He died in 2006.

State and federal data now show that since 1990, nitrogen spread on fields in Iowa and nine other major US corn-growing states has increased 26%, with more nitrogen than ever pouring off the land and polluting US waters. Demand for corn is high, both to supply ethanol refineries and to feed industrial livestock operations that add to water contamination themselves through manure runoff, according to the US Department of Agriculture.

In Iowa alone, according to state research, farmers apply about 2 billion pounds of commercial nitrogen annually to corn fields, and much of it is ending up in waterways that flow all the way to the Gulf of Mexico, worsening the conditions in a 6,500-square-mile “dead zone” where the waters are so oxygen-deprived that they can’t sustain marine life. Iowa contributes almost a third of the nitrogen scientists say causes the dead zone.

Ground Zero”
“Iowa is sort of ground zero for the interface between ag and environment,” said Matt Liebman, a former colleague of Fred Blackmer’s who retired as a professor of agronomy at Iowa State University (ISU) in 2021.

“There’s a lot of money involved. The people who sell inputs and the people who process and distribute commodities, livestock and crops are very interested in making sure that the system is arranged so that money flows in particular ways,” Liebman said. “One side is real small and the other side is very well funded. It can get pretty ugly.”

In Iowa, as in other corn-growing states, many farmers often apply nitrogen in quantities not necessarily aligned with crop needs but in amounts designed to overload the soil in case heavy rains wash away needed nutrients. Farmers will apply fertilizer to fallow fields in fall when there is nothing growing, hoping the ground will absorb and hold on to the nutrients, and then spread fertilizer again on the same fields in the spring. The goal is to maximize yield – how much corn they can produce per acre.

A 2014 ISU farmer survey underscored how dependent growers are on over-applying fertilizer. “The perceived economic risks of under-application are high,” the survey reported. “These results likely reflect a reality that the practice of “insurance” over-application is simply a part of staying in business.”

In contrast, Blackmer’s research showed that applying more fertilizer than plants needed had no effect on yield. “What we’ve found is that farmers can substantially reduce their average rates of fertilization and actually end up with higher yields,” he said in a 2002 interview with an Iowa media outlet.

Blackmer also recognized that over-fertilizing was causing an ecological calamity. “What we’re finding is some farmers can lose 70, 80 or 90% of what they put down. One of the most surprising things is many times these farmers don’t even know that they have lost it,” Blackmer added.

A Simple Concept

Blackmer’s “late spring nitrate test” was simple in concept. His test focused on one essential data point: the optimum amount of nitrogen in soil to grow the most corn. His science showed that optimum soil concentration is 20 to 25 parts per million.

Blackmer developed three steps to get there. First, he took soil samples from farm fields, which typically showed background nitrogen levels at under 10 parts million. Second, he developed calculations to add fertilizer in precise amounts to increase soil nitrogen concentrations to the optimum level and sustain it to meet the farmers’ yield goal, whether it was 150, 200 or 250 bushels per acre.

Then he recruited farmers to apply a little bit of fertilizer at planting and a precisely measured volume of fertilizer at least 30 days later, when fast-growing plants were 6 to 12 inches tall. In most cases the test results indicated farmers should spread 60 pounds per acre to grow 150 bushels per acre, or as much as 80 pounds per acre to achieve 250 bu/acre of corn. Corn growers typically apply double that amount.

Among the farmers that experimented with Blackmer’s nitrate test, was Larry Neppl, an Iowa corn grower who saw firsthand that that applying  60 pounds of nitrogen per acre on part of his crop translated to better production than applying double that amount.

“It told me we did not need that extra nitrogen,” Neppl said.

The amount of money wasted by farmers on unneeded fertilizer, at the current price of $1,100 per ton, is estimated at over $400 million annually.

But the over-fertilization of US corn country is not only costly for farmers. The United States has spent over $500 million since 1997 to reduce the expanse of the ocean dead zone that is fed in large part by the nitrogen contamination flowing from Iowa and the other Corn Belt states.

That same tide of nutrients is also expensive for local and state governments with fertilizer-related contamination affecting more than 7,000 drinking water wells in Iowa and an estimated 30,000 private wells in Minnesota, 42,000 in Wisconsin, and thousands more in Illinois, Nebraska, and Missouri. Corn Belt cities are forced to spend tens of millions of dollars and raise residential and business water rates in order to drill deeper wells or install and maintain nitrate removal and filtration systems to protect municipal drinking water.

There is also a cost to human health. The nitrates from the fertilizers also are implicated in the rising rates of cancer in the Corn Belt. In Nebraska scientists have linked exposure to nitrates to a number of soft tissue malignancies. Nebraska has one of the highest rates of pediatric cancers in the US. Iowa announced in February that it now ranks second in the incidence of cancer, and is the only state where incidences increased from 2015 to 2019.

“The heart of what is causing all of this is a cropping system and an economy that is inherently polluting,” said Kamyar Enshayen, director of the Center for Energy and Environmental Education at the University of Northern Iowa, “It’s not something a conscientious farmer can fix. We have all these incentives coming in to keep doing more of this.”

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  1. Michaelmas

    Yves: …how much inertia drives business behavior (and even small farmers are businesses). Many operations would rather stick with settled practices, even when as shown here, they result in waste, undue cost, and damage to critical resources, here water.

    Farmers — and especially small farmers — are stuck in a position where they have to make a large single annual investment, and if their investment goes wrong and their crop is bad, then they’re broke.

    There are now far better alternatives to the situation described here — and the run-off and environmental damage is actually worse this article suggests — such as nitrogen-fixing bacteria —

    Note that this company isn’t in the vaporware stage, but actually in business, making a profit.

    But when making their annual wager on fertilizer and getting it wrong will destroy their family business, farmers are understandably conservative. They’re also out in places like Iowa and vote republican, in many cases. So persuading them to change is a long, slow job.

    Thanks for this article, anyway.

  2. Michael Fiorillo

    I drove through Iowa ten years ago: it was a giant feed corn and ethanol factory, grossly debased from when I’d visited twenty years before that. I imagine it’s gotten much worse with the industrial pig farms, and all of that seems go have worsened the political hardening of the state.

    1. some guy

      There are tiny little vestiges of eco-ag decency in odd little corners of Iowa. The Seed Savers Exchange is based in Decorah, Iowa; and grow-outs its historic gene-bank seeds right there on its Heritage Seed Farm.

      I just have to believe that there are some other little corners of the state where somebody is making a brave last stand for eco-friendly agriculture without using cancer juice.

  3. The Rev Kev

    If farmers are ignoring what Fred Blackmer came up with and as a consequence all the potential savings that they could be making, I can see only one explanation. Those farmers are getting so many subsidies and tax write-offs, that they don’t have to care about being efficient or trying to save money by not using so much fertilizers. Using all that extra fertilizer must be just like a rounding error for them.

  4. Insouciant Iowan

    This is an old, old story among Iowans. Republicans exacerbate the pollution. Democrats roll over.
    Kamyar Enshayen, quoted in the last paragraph, was for many years an advocate for cleaning up Iowa’s streams and waterways and a critic of faux efforts purporting to improve Iowa’s water quality. In recent years, while continuing in his position at The University of Northern Iowa in Cedar Falls he has tempered his remarks.
    Chris Jones who for years monitored the state of Iowa’s water, lamented its pollution, and mocked the state’s pretences at cleaning it up, recently graduated from his job at the University of Iowa to Substack. He was handed his certificate of job completion after interest in his work expressed by a couple of Republican legislators prompted his resignation. Look him up on Substack to read his more visceral accounts of water quality issues. You may also buy Swine Republic, his recently publishe collection of essays.
    The son-in-law of one of the legislators has a large cattle CAFO In NE Iowa situated just above a karst area. Karst is very permeable rock through which water and any waste that infiltrates it flow rapidly into larger waterways.

  5. Piotr Berman

    “The market size, measured by revenue, of the Corn Farming industry was $94.5bn in 2022.”

    Article: “The amount of money wasted by farmers on unneeded fertilizer, at the current price of $1,100 per ton, is estimated at over $400 million annually.”

    I suspect that the figure from the article is wrong, because it would imply that nitrogen fertilizers “gobble” roughly 1% of the revenue from corn, but may be it is correct. If it is close to correct, it explains why farmers add extra fertilizer just in case.

    Nevertheless, there is an excess in US corn production (which uses an excess of fertilizers): 1/3 of the crop is used “to reduce pollution” in a way that produces pollution. In the same time, the cheapest vegetables, carrots onions and potatoes, cost more than dollar a pound in supermarkets. I am not a vegetarian, but were the diet as balanced as 50 (100?) years ago, with many more whole grains, legumes and vegetables and much less meat, Americans could be leaner and healthier. Incidentally, overuse of fertilizers and chemicals in crops to be consumed by humans instead of livestock or ethanol distillation would be better regulated.

  6. John Steinbach

    Grew up in the 50s in a small farm town in Michigan. All the farmers rotated the crops. Corn, winter wheat, alfalfa. The fourth year they’d let the alfalfa grow (fallow) & fix nitrogen. They’d plow it under (green manure), spread cow manure & start again. Prodigious harvests. Co-Op grain elevators at railroad. Different era.

  7. Rip Van Winkle

    Gulf Dead Zone.

    Of course many homeowners with putting green lawns are users, too, waiting for Arnold, Jack, Tiger and Rory to make the scene.

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