Editorial: The nitrogen cycle

We set out last week from Dubuque to follow the Mississippi River down to New Orleans. Adjacent river bottoms rich in fertilizer, freshly planted and exposed, were inundated from heavy spring thunderstorms. Swollen brown tributaries gushed the excess toward the big river and down to the Gulf of Mexico.

There, a dead zone the size of New Jersey kills aquatic life and puts a tremendous hurt on the fishing industry — at an estimated loss of $2.4 billion. Shrimp can’t make it from swampy spawning grounds to deeper water to grow, for lack of oxygen. They’re stunted, which starves the shrimper. Deeper reaches are devoid of life.

The hypoxia zone ebbs and flows from 4,000 square miles to 7,000 square miles depending on spring rains. It probably will grow this year as Iowa received enough rain to lift it out of drought. When the drainage tile lines run in Buena Vista County, the Gulf feels it in the form of nitrate and phosphorous. Over half of the oxygen depletion comes from agriculture, and much of that can be directly traced to Iowa, Illinois, Missouri, Minnesota, Indiana and Wisconsin.

It’s been documented over the past 50 years but despite all the talk the dead zone persists as a harbinger of what lies in store.

“It’s scary,” said Dr. Nancy Rabalais, perhaps the leading authority on Gulf hypoxia along with her husband Dr. Gene Turner at Louisiana State University. “Water is the most limiting resource we have on the planet. It’s what starts wars.”

She has testified before Congress and advised politicians, warning of the myriad dangers to industry, aquatic biosystems and to coastal protection in increasingly violent Gulf storms. Rabalais understands what she is up against, with rows of oil derricks lining the water’s horizon.

Cheap natural gas produced in Louisiana is shipped to Iowa for anhydrous ammonia production, which provides nitrogen for corn. We then ship up to a third of that nitrate back down the river to choke the Gulf in a perverse cycle. She refers to the money stacked against her as “nitrodollars.”

“The nitrogen cycle is very complex,” she said during an interview amid a dousing rain in Baton Rouge on the day of her husband’s retirement party. Lots of interests have a stake in it: the oil industry, the fertilizer behemoths, the herbicide makers, the big food companies.

“I’ve tried to talk about it but I’ve been criticized for what I say. But I have not given up,” she said.

To wit: Lower water quality is linked to excess nitrogen use. Excess nitrogen use is a mark of excess living. She wants people to quit burning ethanol distilled from corn — “It’s not the solution” — and thinks we should eat less meat. She believes concern over local water quality could drive change. The conversation has changed over the past several years in Iowa. Politicians are trying to respond, if ineffectively, to clear public concern over surface water pollution from excess nitrate. They spend money at the margins.

Real change could happen through a conservation-oriented farm bill. But the legislation has been stalled in the House, as we continue to reward a system that fouls the Raccoon River, fosters toxic algae in Saylorville Reservoir on the Des Moines River, and makes Storm Lake a green mess on a hot August day.

“Farm Bureau is very strong,” Rabalais said.

The change in land use has led to the growth and persistence of the dead zone. What was pasture is now in row crops because of the farm bill. It’s a system predicated on the nitrodollar.

“The farming community is held hostage by their loans. They have to farm a certain way. They’re caught in a bind.”

The change in the dead zone, and in the health of Iowa, has been gradual and incipient. The nitrogen cycle’s complexity, from natural gas to corn to ethanol to pipelines carrying carbon dioxide back to fracking holes, makes solutions equally complex. Rabalais hopes people in Iowa can appreciate how we are directly linked to the Gulf fisheries. Just that morning a headline in the Washington Post warned that New Orleans and Baton Rouge will be subsumed by rising waters and eroding coastlines. 

“A lot of lives are at stake,” Rabalais said.