Now's the Time to Test Soil Levels

Crop yields have been enviable through much of the Heartland this year, but big production can also mean a depletion of valuable soil nutrients for next year, says Kansas State University agronomist Dale Fjell.

"We had great summer crops. We've been taking off tremendous yields, but the other thing we're taking off is soil nutrients," says Fjell, who is a crop production specialist with K-State Research and Extension.

Corn and grain sorghum fields in some areas were showing signs of nitrogen deficiency fairly early in the growing season, he says. So, as good as the yields were this year, it's possible they might have been even better.

Fjell says that over the past several drought-plagued years, crops were poor enough in some areas that they may not have taken up nitrogen that was applied to the fields. That may have led to a nitrogen buildup in the soil.

If growers thought that was the case, they may have cut back on fertilizing this year's crop — and understandably so.

"No matter what, however, now's a good time to test soil in fields where row crops will be planted next spring," Fjell says.

It's important that growers take a 2-foot profile, as opposed to a 6-inch test, he explained. Nitrogen moves in the soil, sometimes well below 6 inches deep.

"I expect that some of these nutrients — nitrogen, phosphorus and potassium — could be quite low," Fjell says.