Nitrates… The Invisible Threat in Iowa’s (and the Midwest’s) Water
There's a growing crisis that’s hard to see, flowing silently beneath our feet and into our rivers. The problem of excess nitrates in our water.
In a recent conversation on The Prairie Farm Podcast, we sat down with one of Iowa's foremost experts, Dr. Larry Weber, co-founder of the Iowa Flood Center and Director at IIHR—Hydroscience and Engineering. He made it clear that we are on the eve of a water quality crisis, one that requires us to look honestly at how we manage and farm our land.
How Bad is it ACTUALLY
Nitrates are a primary component of the fertilizers that we use on our row crop fields. But a leaky system of pattern tiling and intensified farming practices has led to a massive surplus of these nutrients entering our waterways. Water leaving Iowa’s farm fields can have nitrate concentrations of 30-50 mg/L, far exceeding the EPA's safe drinking water standard of 10 mg/L (Source: U.S. Environmental Protction Agency).
"We're simply not making progress," Dr. Weber stated, pointing to scientific data from the statewide water quality monitoring network he helped create. Despite the goals of the Iowa Nutrient Reduction Strategy, the total nutrient load leaving Iowa has doubled since the plan's inception. This isn't a weather issue; it's a land-use issue. Many people will say it’s a weather issue, but it is not. There were massive storms for many millennia with little affect on the nitrat levels in water.
What can we do about it?
While policies and fertilizer management are part of the answer, Dr. Weber’s work shows the need of rebuilding a more sustainable filtration systems. This is where conservation practices and prairie restoration become critical.
Edge-of-field practices like saturated buffers can intercept tile drainage, using natural biological processes to remove nitrates before they ever reach a stream. Dr. Matt Helmers on another episode of The Prairie Farm Podcast explains that these buffers remove well over 50% of the nitrates before they hit our streams. On a larger scale, strategically placed wetlands act as powerful, living kidneys for the landscape, capturing and processing nutrients from thousands of acres.
This is where the power of native plants comes in. Restored prairies, with their deep and complex root systems, dramatically improve soil health and increase water infiltration. Unlike row crops, which are present for only a few months, a permanent prairie ecosystem works year-round to hold soil, capture carbon, and create a resilient buffer that keeps our water clean. These practices don't just filter water; they create essential wildlife habitat, mitigate flooding, and restore balance to our ecosystem. The path to cleaner water flows directly through a healthier, more diverse landscape.
Check out our native prairie solutions to the nitrate water problem in Iowa and the Midwest.
