In the early 2000s, I wrote a series of Land Stewardship Letter articles about a generic environmental impact statement study that was done on Minnesota’s livestock industry. The final report had an interesting finding related to phosphorus, a key source of crop fertility: small livestock farms had a medium phosphorus shortage of 17 pounds per acre, while the largest feedlots had a phosphorus surplus of 38 pounds.
It turned out the larger operations tended to have less land per animal available to spread the manure; it’s not economically viable 
As journalist Dan Egan writes in the book, The Devil’s Element: Phosphorus and a World out of Balance, such situations have created what he calls the “phosphorus paradox—at the same time as we are drawing down our increasingly precious caches of mineable phosphorus rock we are overdosing our waters with it.”
Phosphorus is part of a mighty trifecta that makes modern agriculture possible. Levels of nitrogen, phosphorus, potassium — N-P-K — are monitored obsessively by farmers and agronomists. As Egan reports, it turns out phosphorus has never been easy to come by — the bones left on European battlefields were once “harvested” for their phosphorus content. The rock deposits we rely on today for phosphorus do not regenerate on a human timescale. Predictions about when we will run out of this element worldwide range from a few decades to 400 years from now.
But as Egan argues, paying attention to worldwide stocks may be moot — it’s the regional exhaustion that may cause the most upheaval in our food supply. Three-quarters of the rock phosphorus consumed in the U.S. is dug up in Florida, and those mines are on pace to be exhausted in as little as 30 years. Between 70% and 80% of the world’s phosphorus is located in Morocco and a Western Sahara territory it controls.
“For one country, essentially one guy — the king of Morocco — to control so much of something every plant so desperately needs is a recipe for global instability, or worse,” writes Egan.
Meanwhile, the reliance of row crops like corn have on phosphorus fertilizer, coupled with the growth of massive CAFOs and their production of phosphorus-laced liquid manure, have made this element a major environmental threat. Algae blooms fueled by phosphorus runoff are destroying water quality across the U.S. In one troubling incident, in August 2014 a plume of toxin produced by phosphorus-fueled cyanobacteria made its way into the Lake Erie water intake for Toledo, Ohio. Overnight, some 400,000 people couldn’t drink the water from their taps. By mid-summer, much of Minnesota’s surface waters will be green with phosphorus-fueled algae, spawning fish kills and making swimming a health risk.
In his reporting for the Milwaukee Journal Sentinel, as well as in his 2017 book, The Death and Life of the Great Lakes, Egan proved adept at relaying “good news-bad news.” The Devil’s Element is no exception. The good news is that in the past we were able to get a handle on the phosphorus problem when states began imposing restrictions on how much of the element could be used in laundry detergents. As a result, lakes and rivers that had been inundated by algae recovered. The bad news is industrial agriculture has brought those algae blooms back with a vengeance.
The Wisconsin-based Egan describes the situation in that state’s Brown County, on the southern end of Green Bay. It’s home to numerous dairy CAFOs, and their manure is making its way into the water, which at times becomes so oxygen-starved that fish escape by flopping onto land. Residents have turned to using leaf blowers to push asphyxiating fish back into the water.
Egan would like to see heavier restrictions on how large farming operations utilize fertilizer and produce manure waste. There’s no doubt that at least the threat of a stick can have positive impacts. Shortly after Toledo’s algae bloom debacle, I was on a Land Stewardship Letter reporting trip in neighboring Indiana trying to figure out why that state was such a leader in cover-cropping. Farmers there repeatedly brought up the Toledo situation, and felt that building soil health was one way to avoid the regulations that could be prompted by such disasters.
So how do we work our way out of the “phosphorus paradox”? Frankly, the ”solutions” part of the otherwise excellent Devil’s Element was the least satisfying. The author describes some exciting ways to stop wasting so much of the element from the time it’s mined to when it’s applied as fertilizer — it turns out people are quite innovative when a scarcity approach is taken to a resource. But he touches all too briefly on efforts to support soil health practices that aren’t as reliant on phosphorus in the first place, and, when it’s applied, create the kind of environment that makes efficient use of the element.
Egan describes one “solution” the owners of dairy CAFOS like to tout: using anaerobic digesters to process manure into fuel. But such technology creates a situation where milk is a byproduct of manure production. In other words, CAFOs will have an incentive to grow even larger, and thus produce even more manure — and phosphorus.
The phosphorus cycle, much like the nitrogen cycle in places like southeastern Minnesota, is broken. We need policies, science, and markets that promote a regenerative farming system that closes the nutrient loop. It would be great to see a journalist like Egan spend time with some of the farmers who are part of the Land Stewardship Project’s Soil Builders’ Network — they are proving a broken system can be repaired. Such connections might not be a big stretch for the writer — at one point he describes a “sustainable dairy farming” system in which a cow grazes on well maintained pastureland, spreading its manure in an even pattern that results in more forage being grown, which in turn is then consumed by the cow.
“And on and on it goes — a virtuous cycle,” writes Egan.
Exactly.
Brian DeVore is the editor of the Land Stewardship Letter, producer of LSP’s Ear to the Ground podcast, and the author of Wildly Successful Farming: Sustainability and the New Agricultural Land Ethic.