These are the good times.
I was driving through the country last Saturday, looking at deer happily chowing down in wheat fields. Everyplace is a drive-through if you’re a herbivore at this time of year.
It’s a simple historical fact that wheat farming has been central to American agriculture since the country was young. And today wheat grown in the U.S. supplies American consumers and millions of other people around the world with large quantities of economical nutrition.
Even a geologist like myself knows that much about the king of grains.
But I was recently startled to learn that the temperatures experienced by American wheat farms back in 1839 were 6.6 degrees warmer than they are today. That’s right, our wheat farmers are now working in temperatures substantially colder than they were earlier in the nation’s history.
At first I thought I had misread the statistic. After all, we know that temperatures in our country from about 1850 onward have been on the uptick as North America has emerged from a cooler time. And, surely, if climate scientists are right, temperatures in just the past couple of decades are clearly up from what they used to be. So how could modern American wheat farmers be facing much colder climes than they were in 1839?
The answer is that wheat is now raised well to the west and north of where it was in the 1830s. Back then, the geographic center of wheat production was in eastern Ohio, not far from the Pennsylvania line. Now counties in central Montana, a corner of Wyoming, a strip of Colorado and Kansas account for much of the American wheat that’s planted in the fall, while spring wheat comes largely from North Dakota.
Obviously, those are not balmy parts of the country.
The main reason modern farmers can grow wheat in places like Montana is that immigrants who came to the U.S. in the 1870s from the Russian steppes brought with them a winter-hardy strain of wheat called the Turkey variety. From that base, modern scientific breeding of wheat also helped make a wide range of cold-tolerant wheat varieties possible. Beyond that, modern “no-till” farming that leaves stubble in the field helps to prevent snow from blowing away, insulating tender wheat seedlings from bitter winter frosts.
Here’s the bottom line: the temperatures under which American wheat has been grown since the 1830s have changed more than the climate change predicted by experts from here to 2050. That’s a hopeful sign about natural plant resources – embedded in the many types of wheat – and about the agricultural technology we have at our disposal to adapt to what may come down the road at us in terms of climate.
And, actually, there are a number of things about warmer temperatures that may help wheat farmers if predictions about 2050 hold true. In general, warmer conditions accelerate growth, usually a good thing for farmers. A potential negative is the drying of soil. Experiments on wheat under different temperature regimes show a complex impact on yield, with much depending on when wheat is planted – happily one variable that’s very much under the farmer’s control.
According to what I’ve read and to the agricultural scientists I’ve spoken to, it’s really not average temperatures that cause farmers headaches – it’s variations. A truly cold or hot growing season is a greater problem than changes in average temperature over time.
“Although our average temperatures for the whole globe are increasing, temperature in some regions will decrease because of changes in weather patterns,” wheat scientist Prof. Tim Murray of Washington State University reminded me recently.
“Unfortunately, more severe weather is part of what’s predicted, and this year looks like it will be an example of conditions that depart noticeably from what’s average,” Murray said.
What is crucial is whether we can stay ahead of the weather curve.
“Climate change is one of the reasons breeding programs are never-ending,” Murray told me. “Wheat has the genes to adapt to many conditions. The trick is finding those genes and incorporating them into new varieties at a pace that keeps yields high.”
Our daily bread depends on it.