Recent rainfall has improved soil conditions immensely in some parts of the Corn Belt. But, the subsoil moisture worries aren't over in other areas.

One area of great concern right now is northwestern Iowa. The top 5 feet of that area's soils typically hold 10 to 11 inches of moisture this time of year. But, after last year's dry summer, those levels are closer to half their normal levels.

"Soil moisture levels at these sites range from 5.7 to 7.2 inches of plant-available moisture," Iowa State University Extension field agronomist Paul Kassel says of 3 sites in northwest Iowa.

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It's not the end of the world for your crops right now. But, Kassel says it puts all the pressure on summer rainfall.

"If spring rainfall does not replenish soil moisture reserves in late April or May, crops will be more dependent on summer rainfall. Corn and soybean crops require about 22 inches of soil moisture to produce a normal crop," he says. "Therefore, normal summer rainfall -- which is about 18 inches for May to mid September -- will be needed to produce a normal sized corn and soybean crop.  Rainfall usually contributes about 80% to soil moisture levels."