"This is particularly a problem in soils with a high clay content," said Jim Shroyer, crop production specialist with K-State Research and Extension.

Heaving occurs when a layer of moisture-charged soil freezes and thaws, causing expansion and contraction, while the underlying layer is stationary. The movement can break off a plant’s roots and push the crown above the surface of the soil by a fraction of an inch to as much as several inches.

Wheat fields that have been subject to heaving will still green up because there are carbohydrates stored in the crown of the plant, Shroyer explained. The plant can live off of that stored carbohydrate for a time, but as those reserves die out, the plant also will die.

The situation is sometimes mistaken for an insect or disease problem at that point, he added.

There is little a wheat grower can do if a field has been hit hard by heaving, other than to consider if there’s enough of a stand left to merit staying with the wheat or planting a row crop on the field instead, Shroyer said.

He reminded growers that if a wheat field was already fertilized before the decision to switch to a spring row crop was made, the fertilizer will be fine for the row crop, too.

Herbicides are a different matter, however, as some residual herbicides meant to be used with wheat may harm a row crop.

In alfalfa, if the crown is not pushed too far out, the plant will still produce foliage although possibly somewhat less than would a healthy plant.

"Sometimes the real damage doesn’t show up until swathing time. If the crown is 1-1/2 inches or more out of the soil, it’s subject to damage by the haying equipment," he said. "If an alfalfa grower is aware that heaving has pushed the crowns far enough out of the soil, he or she should raise the swather height to avoid crown damage."

He suggested that farmers let the affected alfalfa fields reach the quarter- to half-bloom stage before harvesting.

"They’ll get more tonnage but less quality," he added.

An added problem for alfalfa may not occur until next winter.

"If crowns are exposed to the elements next winter, they’ll be more vulnerable to winterkill," the agronomist said.

"People often ask if it’s a good idea to push the crowns back into the soil with a roller cultipacker. We don’t recommend that," Shroyer said, adding that could also damage the crowns.