Crops withered under searing heat and very little rainfall during July in south-central, southeast and northwest Iowa, farmers and agronomists said last week.

Moderate to severe drought conditions gripped more than one-third of the state last week, according to the National Drought Monitor, and another one-third of the state was classified as abnormally dry. Rains late last week brought some relief to the drought-stressed areas, but farmers said much more will be needed to recharge soil moisture.

"I haven’t checked the rain gauge yet, but I would guess we had three-tenths of an inch, if that," said Corey Malichky, who farms in Washington County. "It was enough to settle the dust, but that’s about it."

Crop conditions took a turn for the worse during the second half of July as thirsty crops...