What to do with ice in wheat fields

The weather has provided a variety of winter hazards for wheat.

Heavy rain that subsequently froze, freezing rain, snow followed by freezing rain have added to the diversity of situations throughout the state.

The ground has been frozen since the first week of January when we had a short thaw period.

Reports now indicate that the soil is frozen down to about 18 inches or more.

Snow cover is very important for protecting the wheat during the times when we have colder temperatures.

Patches of ice in wheat fields during the dead of winter do not damage the wheat crop for the most part because the crop is dormant.

This assumes that the wheat plants are well-rooted and the base of the crowns of the plants are properly placed at about one inch below the soil surface.

Ice melt. The damage comes when the ice melts, forming pools of standing water that partially or totally covers the plants.

If the plants are dormant, standing water may have little or no negative effects.

However, for plants no longer dormant, standing water pushes all the air out of the soil and deprives the root systems of the oxygen they must have to survive.

If the standing water drains off the surface before plants come out of dormancy so that oxygen can get to the root system, then the plants should survive.

The length of time plants can survive in standing water depends on the rate of metabolic activity, which is a function of temperature.

Metabolism slows as the temperature decreases and results in a reduced demand for oxygen. Thus, plants can survive flooding longer at low temperatures than at higher temperatures.

If the thaw is sufficient to melt the ice and the soil around the wheat plants and low temperatures cause the water to refreeze, the plants may be heaved out of the soil making them vulnerable to cycles of freezing and desiccation (like freeze drying).

Action. No action should be taken at this time or later this spring to eliminate ice problems in wheat fields.

Good surface drainage is the key to preventing this problem and is a must for the survival of any crop in the field over winter.

Land forming/leveling will eliminate the low spots in a field that collect water leading to crop damage or loss.

Where no-till culture is practiced, the effects of land leveling will be effective for many years compared to fields where tillage is used, making leveling more affordable.

Examine. Begin to examine wheat fields in early spring as the time for green up approaches.

Dig plants from the field, wash off all soil and examine the crowns. Peal the leaf sheaths down to expose the inner parts of the crown.

The tissues in healthy plants should be a creamy white color.

If the internal tissues are brown or discolored, then these plants are likely dead or will soon be dead.

At this time you can also examine plants for soil heaving. Plants heaved out of the ground exposing the lower crown and roots will likely die by mid-April.

There is no need to assess fields before green up because the weather in February and early March very frequently determines the fate of the field.

Any decisions you make now will likely change within the next month or so.

(Pat Lipps is an Ohio specialist in plant pathology, and Jim Beuerlein is a specialist in soybeans and small grain.)