Corn belt moves north, west with climate

Charles Brown
Charles Brown

The official statistics have yet to come in, but early indications suggest that Iowa’s corn yields were good in 2018.

However, some parts of the state suffered through a drought, and that included part of southeast Iowa. Iowa State University Extension and Outreach farm management specialist Charles Brown said farms near Fairfield had decent yields, but those in the southern part of Jefferson County, and especially in Davis and Van Buren counties, didn’t fare as well.

“The yields in the central third of the state were excellent,” he said. “But those two counties in the south, along with Appanoose and Wayne counties, were terribly dry from June through August. A lot of those areas had less than an inch of rain. They didn’t get the moisture they needed to make the grain.”

The only saving grace about a drought is that it’s as hard on pests as it is on crops. Brown did not hear many if any complaints about bugs.

“The same thing was true for crop diseases,” he said. “Moisture and high humidity activate most diseases, and it was too dry for them in this part of the state.”

The most important month for determining the fate of corn is July. Good weather during that month means the ear will fill out nicely without aborting any kernels. The size of the ear is determined earlier in the year, and the number of kernels is determined in June.

Soybean yields followed a similar story as corn. The yields were higher than expected, with great yields in the central third of Iowa but not as good in the south because of the drought.

Climate change

Brown said one of the most interesting trends in corn growing is that the corn belt is moving north and west. Why? Because of changes in the earth’s climate. He said North Dakota is producing a lot of corn now, something it did very little of even 10 years ago.

“We’re seeing corn in Canada, which was rare before,” he said. “Even if corn was planted in that part of the continent, it would have been for silage, meaning the whole plant is harvested for feed.”

Climate change figures to alter the type of seeds farmers use, too. Seed companies have become skilled at designing seeds uniquely suited to thrive in a certain locale. For instance, farmers in southern Iowa typically buy corn seeds that mature in 110-115 days, whereas northern Iowans tend to use seeds that mature in 100-105 days. Seed companies have bred varieties used in Minnesota and even farther north that mature in as few as 85 days.

As corn enters new terrain to the north and west, it’s slowly vacating other parts of North America. Brown said southern states are raising more soybeans and cotton. He thinks there may come a time in the next 30 years when even parts of southern Iowa will abandon corn in favor of wheat, oats, barley and rye, or perhaps return it to pastureland.

“Southern Iowa used to have a lot of cow-calf herds,” he said. “It became corn-heavy when corn prices rose, but a lot of this ground is really better suited for pasture.”


Some states like Kansas and Nebraska have turned to irrigation to grow corn and soybeans to compensate for the lack of rain they receive. However, the irrigation has been so extensive it’s having a noticeable effect on the water table.

Iowans largely do not irrigate their fields, but they could be facing water-related problems in the coming years. Brown said rainfall is not necessarily decreasing but is becoming more erratic. For instance, instead of many light showers throughout the year, the state receives 4-5 inches of rain in the spring and fall, but little in the summer when the crops need it.

On top of climate change, farmers must worry about the natural fluctuations in weather patterns from year to year. For instance, by looking at 600 years of tree ring data indicating how much a tree grows in a certain year, scientists have learned that Iowa experiences a heavy drought every 18-19 years, and a truly severe drought every 88 years, “one like you and I have never seen before,” Brown says.

The last severe drought occurred around 1935-36, so the next one is due around 2023-24.


The futures price of corn sits at about $3.80 per bushel, and its cash price is between $3.50 and $3.60. Soybeans, meanwhile, are going for $9.20 per bushel on the futures market, with the cash price about 70-80 cents less.

About six years ago, the price of corn rose to over $7 per bushel. Those days are gone, and Brown doesn’t think they’ll come back anytime soon.

“These prices we have today are the ‘normal’ prices,” he said. “The period from 2008-2013 was the aberration in the market. A lot of things came together to raise the price of corn. You had new ethanol plants coming online, increasing world demand for corn, and the drought of 2012, which reduced the supply, driving up the price.”


As commodity prices have fallen, expenses have fallen, too, but they lag behind. That means farmers have been forced to dip into their savings from that golden era less than a decade ago when farming was so profitable.

Brown said some expenses aren’t coming down much at all. He mentioned that landlords have been reluctant to reduce rents because they’ve grown accustomed to a certain amount of income.

“Fertilizer costs came down last year but they went back up, and the same thing happened with seed,” he said. “Seed companies have money invested in new varieties, and all that investment takes money.”

Brown said a number of farmers of retirement age stuck with the profession because the commodity prices were so high, and because modern technologies like auto-steer have made farming easier. Now that commodity prices have come back to earth, those farmers are ready to hang up their overalls.

“I’m seeing a lot of farm sales now,” Brown said. “It’s not as much fun selling corn for $3.50 a bushel.”