Research forecasts Iowa corn yields could drop in half within the next half-century thanks to extreme weather – yet it’s not part of the political conversation

Farmers around here are itching to go after that amber wave of soya beans, but there was that 5in rain a couple of weeks ago and then a 7in rain, and it drives even the retired guys batty.

Those beans aren’t worth much at the elevator thanks to a Trump trade war with China, but they’re worth even less getting wet feet in a pond that was a field which the glacier made a prairie bog some 14,000 years ago – until we came along and drained it.

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This year, crops in north-west Iowa are looking spotty. Up into Minnesota they were battered by spring storms and late planting, and then inundated again in late summer. Where they aren’t washed out, they’re weedy or punky. If you go south in Buena Vista county, where I live in Storm Lake, the corn stands tall and firm.

Welcome to climate change, Iowa-style.

It’s the least debated issue of the midterm political season. The weather is the top topic of conversation at any cooperative elevator’s coffee table, along with the markets. Everyone knows that things have been changing in sweeping ways out here on the richest corn ground in the world. It’s drought in the spring and floods in the fall – what were considered 500-year floods in Cedar Rapids and Des Moines 30 years ago are now considered 100-year floods. Iowa has been getting soggier in spring and fall, with scary dry spells interspersed, and more humid at night by as much as a third since 1980.

Everyone knows it has been getting wetter and weirder, especially Dr Gene Takle, a climate scientist at Iowa State University who contributed to reports for the Nobel peace prize-winning IPCC. Takle predicted 20 years ago the floods we see today, already linking it to climate change back then. Farmers just saw ponding and called the tiling company to install more. We’re on our way to doubling the size of the northern Iowa drainage system in the past 30 years as the upper midwest has grown more humid and extreme.

This drainage system is delivering runoff rich in farm fertilizer to the Mississippi river complex and the Gulf of Mexico, where the nitrate from Iowa and Illinois corn fields is growing a dead zone the size of New Jersey. The shrimping industry is being deprived of oxygen so Iowa farmers can chase 200 bushels of corn per acre – and hope against hope that corn will somehow increase in price as we plow up every last acre.

That flow also is creating a toxic source for Des Moines Water Works, which is facing up to $100m in improvements to remove agricultural chemicals from the Raccoon river that supplies 500,000 thirsty denizens. The waterworks sued our county over it, along with two others, but a federal judge threw out the case because you simply can’t sue an Iowa drainage district. And that means that there is no way to regulate agriculture as it responds to extreme weather and market consolidation that seeks immediate return.

Meanwhile, those huge rainfalls on exposed black dirt wash it to the vales even from the flat ground of our neighborhood. We are losing soil at two to three tons an acre a year. Nature can regenerate the soil at only a half-ton a year. So we are washing our black gold down the river four to six times faster than we can regrow it.

Because we have less soil, the corn and soya beans are starting to show it in lower protein in the kernel or pod. Corn is yielding higher starch content, notes agronomist Dr Rick Cruse of Iowa State. He adds that wheat production in China is falling because of degraded soil wrought by extreme weather and poor stewardship. It follows that overall corn yields, or at least relative value for the most-used crop in the world, will decline.

Here, this year, we see it in variable crop yields from township to township. It is starting to factor into land prices, which is the foundational wealth of the upper midwest and especially in Iowa.

The University of Minnesota forecasts, based on research at Nasa, that Iowa corn yields could drop in half within the next half-century because of extreme weather and soil depletion.

Yet nobody is talking about it. We expect that the chemists and geneticists will handle it and keep those yields ramping up come hell or high water.

Facebook Twitter Pinterest A lone cow wanders charred prairie following devastating wildfires in Clark county, Kansas. Farmers and ranchers on the high plains are struggling amid a lengthy dry spell and the aftermath of destructive wildfires. Photograph: Michael Pearce/AP

Down in Kansas, they are resigned to the fact that the water will be gone sooner rather than later. The high plains are locked in drought. You used to run a calf on 40 acres of prairie grass; now it takes 100. Depending on the source, you will hear that the Ogallala Aquifer slaking the huge cattle feedlots from Amarillo to Dodge City will be drunk dry in as few as 20 years. It’s down 150 feet at Dodge City since 1950. The Ogallala can’t take much of a recharge there. And the demand on the rivers is just as great.

“Everybody acknowledges that those cattle will just move to another area,” said Don Blankenau, an attorney for the state of Nebraska, in its compact with Kansas that regulates the Republican river from which cattle and corn irrigators draw from ever-lower flows.

But it’s not a part of the political conversation per se. Nobody is talking about climate change in their campaigns, or the implications for food production near-term, or how water will be handled in fast-changing conditions. It is one of those electric rails, because so much money is wrapped up in the corn-ethanol-meat-soya bean complex as it stands.

Farmers are taking action on their own, after losing money six straight years in Iowa and wondering where the corn ethanol bubble of 2008 went. They are starting to look into cover crops like rye to protect the soil and hold nutrients in place during these increasingly harsh flushes. They also can help store moisture by building soil tilth to ward off dry spells, which could span decades. “You have flavors of the Dust Bowl,” Takle said, sprinkled by torrents in the future.

Another soil scientist, Jerry Hatfield of the National Lab for Agriculture and the Environment in Ames, told my reporter son Tom that we can make agriculture resilient to a changing climate. But it will take a transformation in thinking that is not yet reflected in the political conversation.

Few politicians in the five states around here are talking about regulating agriculture in an era of warmer and wetter nights and long droughts. Yet farmers are paying attention. Hatfield says that conventional producers in the Raccoon river watershed are starting to focus on profitability reports from sustainable agriculture groups like the Practical Farmers of Iowa. They advocate a rotating crop-livestock land use with more diverse plantings that can restore soil and make farmers more resilient – and get them off that expensive chemical jones. Because, the government doesn’t appear equipped to deal with it.

The state of Iowa and the state of Ohio each spend about a dollar per acre per year on water and soil quality – on land that costs up to $10,000 per acre. Politicians are still talking bioswales and mini-marshes when we all need to be thinking, at least, about retiring a third of the land in the upper midwest from corn and soy rotations.

That isn’t something that the ag supply chain – controlled by the Koch brothers, Bayer-Monsanto and Dow-Dupont – can readily accept, because to give up acres is to give up revenue. And they happen to control the political infrastructure in the Corn Belt.

But at some point the construct fails. In western Kansas, they’re having a tough time growing corn even with irrigation and chemicals. It is getting so warm that the plant simply cannot service itself.

Without more urgency, the problems will continue to grow worse than soya beans standing in six inches of water waiting on a combine to sweep them up. The fellows around the coffee maker know it. And so do the people down in Des Moines trying to make a safe cup of coffee, along with Amarillo ranchers.

The politicians just haven’t caught up.

• This article was amended on 24 October 2018. Dr Takle has not won a Nobel prize, as suggested in an earlier version; he contributed to reports for the IPCC, which won the Nobel peace prize in 2007.