Lack of rainfall deteriorating crop condition, soil moisture levels

The drought is returning.

The moderate drought and abnormally dry conditions that began creeping into southwest Iowa last month is stressing the state's corn and soybean crops with little or no relief expected into September.

The U.S. Drought Monitor map released Thursday, reflecting conditions at 7 a.m. Tuesday, showed moderate drought spreading eastward from southwest Iowa.

Extreme southern Linn County and all Johnson County are shown as abnormally dry.

Northeast Iowa farmers were helped by heavier spring rains - but the extreme northern counties are shown as abnormally dry, and corn is showing some stress from lack of recent rainfall.

KCRG Meteorologist Kaj O'Mara said little relief is expected, with computer models forecasting the rest of the month will be hot and dry.

"We've had 0.6 inches of rain at The Eastern Iowa Airport and o.o4 inches in Iowa City for the month of August," O'Mara said. "The main storm track will likely stay up at the U.S.-Canadian border, which for us will mean an occasional cold front.

"I would be hard-pressed to see any improvement in next week's drought monitor map, especially with the heat we are expecting."

A slow, steady rain is needed to improve soil moisture, O'Mara said. Any heavy rain likely would run off rock-hard ground into streets, streams and rivers, he explained.

"This year is really running parallel to 1947," O'Mara said. "That year saw snow in May, a wet spring with 10 inches of rain in June, a dry July and August, precipitation at or below normal through November, and higher-than-normal temperatures."

The U.S. Department of Agriculture on Monday reported that there was an average of 6.4 days suitable for fieldwork statewide in the week that ended on Sunday. Southwest Iowa received the most rainfall during the week and had the least days suitable for fieldwork with 5.8.

A total of 35 percent of topsoil and 41 percent of subsoil was in the adequate and surplus moisture categories - both declining 6 percent from last week.

Topsoil moisture levels were rated 25 percent very short, 40 percent short, 34 percent adequate and 1 percent surplus. Subsoil moisture levels were rated 19 percent very short, 40 percent short, 40 percent adequate and 1 percent surplus.

Corn conditions declined slightly from the previous week, and was rated at 5 percent very poor, 13 percent poor, 34 percent fair, 40 percent good and 8 percent excellent.

With nearly all the corn crop tasseled, 93 percent was silking, behind the five-year average of 99 percent. Sixty-two percent of the corn crop reached the milk stage, trailing the normal 87 percent.

Twenty-four percent of the corn crop has reached the dough stage - when kernels attain about 50 percent of their mature dry weight - well behind the normal 60 percent. Some of the very earliest planted corn crop has reached the dent stage - when kernel moisture content is at about 55 percent.

Soybean conditions declined slightly from last week and was rated 5 percent very poor, 12 percent poor, 36 percent fair, 38 percent good and 9 percent excellent.

With 95 percent of the soybean crop blooming, pods were being set on 71 percent of the soybean crop, well behind last year's 94 percent and the normal 89 percent.

The third cutting of alfalfa has reached 36 percent compete, 9 days behind the normal pace. Both hay and pasture conditions continued to deteriorate with 4 percent rated good and 3 percent excellent.

Hay condition was rated at 5 percent very poor, 13 percent poor, 36 percent fair, 40 percent good and 6 percent excellent. Pasture condition rated 10 percent very poor, 22 percent poor, 40 percent fair, 25 percent good and 3 percent excellent.