New problems arise for crop storage as planet gets warmer

MECOSTA>> For generations, Brian Sackett’s family has farmed potatoes that are made into chips found on grocery shelves in much of the eastern U.S.

About 25% of the nation’s potato chips get their start in Michigan, where reliably cool air during September harvest and late spring has been ideal for crop storage. That’s a big reason why the state produces more chipping potatoes than any other.

But with temperatures edging higher, Sackett had to buy several small refrigeration units for his sprawling warehouses. Last year, he paid $125,000 for a bigger one. It’s expensive to operate, but beats having his potatoes rot.

“Our good, fresh, cool air is getting less all the time, it seems like,” he said on a recent morning as a frontend loader scooped up piles of plump, light-brown potatoes that would be packed into a tractor trailer for shipment to chip factories.

The situation here illustrates a little-noticed hazard that climate change is posing for agriculture in much of the world. Once harvested, crops not immediately consumed or processed are stored — sometimes for months. The warming climate is making that job harder and costlier.

The annual period with outdoor air cool enough to store potatoes in Michigan’s primary production area likely will shrink by up to 17 days by mid-century and up to a month by the late 2100s, according to an analysis by Julie Winkler, a Michigan State University geography and climate scientist.

The window for unrefrigerated storage is also narrowing for apples in the Northwest and Northeast, peanuts in the Southeast, lettuce in the Southwest and tomatoes in the Ohio valley, according to follow-up research published last year by plant physiology scientist Courtney Leisner at Auburn University.

Techmark Inc., an agricultural engineering company based in Lansing, Michigan, designed the Sackett farm’s equipment. Co-owner Todd Forbush, whose customers also include growers of sugar beets, onions and carrots, said storage of those crops increasingly will need refrigeration.