Opinion: Check data, and also your senses, on Iowa water quality

We invite you to visit a stream or lake near your home. Does the water look and smell the way you think it should?

Matt Liebman, Larry Weber and Chris Jones
Guest columnists
  • Matt Liebman is professor emeritus of agronomy and former H.A. Wallace Chair for Sustainable Agriculture at Iowa State University.
  • Larry Weber is director, Center for Hydrologic Development, and Edwin B. Green Chair in Hydraulics, IIHR-Hydroscience & Engineering at the University of Iowa.
  • Chris Jones is research engineer with IIHR Hydroscience & Engineering at the University of Iowa.

As Iowans with more than a century’s worth of work in environmental science and agronomy between us, we applaud the efforts of all those who seek to develop and implement farming practices that protect water quality, promote rural prosperity, and sustain crop and livestock production. But, as scientists, we also know the importance of relying on credible information, especially when it comes to making management decisions. That requires being skeptical of assertions that are not accompanied by an adequate amount of supporting evidence and that fail to acknowledge the relevant findings of other investigators.

We were therefore surprised to read in the Register that “Iowa farmers have made huge strides in water quality.” Published data show statewide stream nitrate levels doubling since 2003 and tripling in streams draining to the Missouri River, and no progress in reducing phosphorus levels. The author asserts that last year “nearly 3 million acres of cover crops were planted in Iowa.” But a 2022 study published by scientists at Stanford University and the University of Illinois, conducted with high resolution satellite data, indicates that cover crops were used on less than a third of that area in 2020, with a downward trend since 2018. As scientists, we recognize that quantitative estimates of landscape-level features can differ, but we adhere to an ethic that requires us to identify where and when large discrepancies exist.

We believe that Iowans are fully capable of using their own eyes, ears, noses, and memories to assess whether the state is making substantive progress in improving water quality. We invite you to visit a stream or lake near your home. Does the water look and smell the way you think it should? Are the species there that you think should be there? Are the streams buffered with setbacks for crops, or does the stream flow through a dirt-lined canyon vulnerable to flashy hydrology caused by drainage tile and stream straightening? Are corn and soybean plants sloughing off into your stream? Are cattle wading in it? Are the beaches you go to safe for swimming, or are they posted with notices about pathogenic organisms and toxic algae? Some people, in some parts of Iowa, may honestly report that the water seems adequate to them. For many others, our water quality is not close to being adequate and hasn’t been so their entire lives.

The corn-soybean-CAFO-ethanol system that currently dominates Iowa agriculture has been profitable for some, but it has been made possible by taxpayer-funded insurance subsidies and government mandates for ethanol consumption. It has also been accompanied by growing susceptibility to deadly pathogens like avian influenza. We believe it’s time for a new vision for Iowa. Diverse crop rotations and alternative livestock systems would produce better environmental outcomes and create better opportunities for young and imaginative farmers to get a foothold in an occupation that has been made off limits by high land prices. As taxpayers who contribute to Iowa farm income, the public should have a say in how that system is operated. Being clear about whether we’re actually making progress toward cleaner water would be a good place to start.

Matt Liebman is professor emeritus of agronomy and former H.A. Wallace Chair for Sustainable Agriculture at Iowa State University. Larry Weber is director, Center for Hydrologic Development, and Edwin B. Green Chair in Hydraulics, IIHR-Hydroscience & Engineering at the University of Iowa. Chris Jones is research engineer with IIHR Hydroscience & Engineering at the University of Iowa.