Opinion: What if I told you that a solution to Iowa's water quality was right in front of us all along?
Water quality is in the news, with Iowa’s Supreme Court ducking responsibility for the issue and Des Moines Water Works looking to spend millions to drill wells rather than rely on polluted river water. Some people appear ready to give up, believing water quality can’t be addressed if King Corn and ethanol are Iowa’s future.
Not everyone has given up hope, I believe answers are available if we’re smart enough to embrace them.
What if I told you a science-based tool, created at Iowa State University, could save farmers tens of millions of dollars and not reduce corn yields?
What if this “solution” is recommended by the Nutrient Reduction Strategy — the only solution included in every scenario used to validate it?
What if the strategy can keep 400 million pounds of excess nitrogen from being applied on fields where it isn’t needed and leaking into tile lines and streams adding to the pollution Iowa sends to the Gulf of Mexico?
What if this ”system” is available free to all Iowa farmers, easy to apply, and voluntary?
You might say, “Professor, this sounds too good to be true!” But this magic bullet exists and the claims are true! The tool is the Maximum Return to Nitrogen calculator or MRTN, created by researchers at Iowa State and other Midwest universities, and validated on farms across the state.
The calculator — available online — is easy to use. Plug in the cost of nitrogen fertilizer per pound, the projected price of corn, and if planting corn following corn or following soybeans (which provide some nitrogen). Push a button and the calculator shows the amount of nitrogen needed to achieve 99% of yield goals. The numbers vary depending on locations, but the average MTRN for 2020 was estimated to be 145 pounds per acre.
This is the starting point, but the story gets murky. Best estimates are nitrogen actually used in 2020 on Iowa’s 14 million corn acres was 175 pounds per acre — 30 pounds more than recommended. Much of the additional 400 million pounds of nitrogen, costing farmers and landowners over $100 million, was “wasted” because plants couldn’t use it so most potentially leaked into our waters.
You may be ready to shout “Glory, Hallelujah — finally, a tool farmers and farm groups can rally behind!” They can avoid the dreaded threat of “one-size-fits-all regulations” feared more than a phantom death tax!
Here the story gets puzzling. Have you ever heard a politician extol the virtues of the MRTN or promote it? Have you seen a "Farm Bureau Minute" or public service announcement encouraging farmers to take the pledge and apply nitrogen at the MRTN? No, you haven’t — because no one is willing to suggest Iowa farmers can use less fertilizer. It’s a forbidden topic. An exception is the Iowa Soybean Association working to protect water quality and improve fertilizer management.
Instead, most of what we hear about is practices like installing bio-reactors, which work part of the year, or planting cover crops and other after-the-fact efforts to remove nitrogen and reduce pollution. Stories always note how costly these are and how the public will have to pay if it expects cleaner water.
Why not just say, “Let’s stop using so much nitrogen in the first place!” It won’t cost the public a dime and will save farmers millions. Sadly, the story is even worse because MRTN calculations do not include the countless tons of hog manure applied in Iowa, adding nitrogen many farmers don’t even consider in fertilizer decisions. If manure was credited, less nitrogen would be purchased.
So why does this happen? Why waste money on fertilizer not needed — and why don’t officials promote an available solution to actually improve water quality? One answer is that nitrogen is relatively cheap, good insurance for large yields. No farmer wants a crop to run out of nitrogen, and some may feel the MRTN doesn’t account for field variability. Another answer is who pays when excess nitrogen runs off. Farmers and landowners bear no risk and pay no price to clean the water; instead, the public and folks like the Des Moines Water Works are expected to pay to address water pollution.
Are politicians and farm groups so timid and afraid to even suggest farmers use too much fertilizer and are part of the problem, when the evidence is clear?
If you think Iowa should get serious about addressing water quality, expecting leaders to promote the MRTN seems like a good place to start. Iowans pride ourselves on having common sense. Being smart enough to use the tools we have is a good way to prove it.
Neil Hamilton is emeritus professor of law at Drake University and former director of the Agricultural Law Center.