Many cornfields in Iowa lost yield potential due to continued dry weather last week. USDA’s weekly crop and weather report as of Aug. 13 shows the statewide corn condition has declined to 3% very poor, 9% poor and 27% fair. Only 61% of the 2017 Iowa corn crop is rated good-to-excellent.

Soybean condition is rated 4% very poor, 11% poor, 29% fair. Only 56% of Iowa’s 2017 soybean crop is good-to-excellent.

“As dry weather continues, we see the portion of Iowa in drought continuing to expand and crop conditions continue to deteriorate. Unfortunately, 40% of the state, including parts of 23 counties, is now in severe drought,” notes Iowa Ag Secretary Bill Northey.

40% of Iowa in severe drought
Conditions continue to be driest in southeast, south-central and northwest Iowa. Dry weather is lowering yields, drying up pastures and threatening farm finances. Farmer Colin Johnson in southeast Iowa, near the town of Agency, says his yields will be dismal — perhaps 25 to 80 bushels of corn per acre on fields that averaged 180 bushels or better last year. “We will be lucky to get 100 bushels an acre,” he says.

At most, crop insurance will cover 85% of losses. But most farmers insure their crops at lower levels, says Charles Brown, an Iowa State University Extension farm management specialist in southeast Iowa. “That won’t cover the cost of production. But it is better than nothing.”

The complete weekly crop and weather report is available on the Iowa Department of Agriculture & Land Stewardship’s website IowaAgriculture.gov or on USDA’s site nass.usda.gov/ia. The report summary follows.

Summary of Iowa crop conditions
All of Iowa experienced cooler-than-normal temperatures with very little rain scattered across the state during the week that ended Aug. 13reports USDA’s National Ag Statistics Service. Statewide there were 6.3 days suitable for fieldwork. Activities for the week included applying fungicides, insecticides, grain hauling and haying.

Topsoil moisture levels fell to 30% very short, 33% short, 37% adequate and zero percent surplus. According to the Aug. 8 U.S. Drought Monitor, Iowa’s region of drought expanded to 40% of the state, including portions of 23 counties in severe drought. Subsoil moisture levels rated 25% very short, 33% short, 42% adequate and zero percent surplus. That is the highest percentage of very short subsoil moisture supplies since the first week of November 2013.

Corn crop condition declined last week
Iowa’s 2017 corn crop as of Aug. 13 was 62% in or beyond dough stage, six days behind last year. And 8% of the corn crop has reached dent stage, one week behind average. Corn condition declined to 3% very poor, 9% poor, 27% fair, 52% good and 9% excellent.

Soybeans blooming reached 94%, five days behind last year and 4 days behind average. Iowa’s soybean crop is 82% setting pods, three days behind last year, but two days ahead of average. Soybean condition is rated 4% very poor, 11% poor, 29% fair, 49% good and 7% excellent. Iowa’s oat crop is 95% harvested, equal to average.

The third cutting of alfalfa hay is 65% complete, eight days ahead of last year and 11 days ahead of average. Pasture condition is reported as 45% poor to very poor, the highest percentage reported in those categories since the beginning of April 2014. Cooler temperatures improved livestock conditions, but supplemental feeding has been required and ponds are drying up in some areas.

Weather summary for Iowa
Harry Hillaker, state climatologist with the Iowa Department of Agriculture and Land Stewardship, provides the following summary for the week ended Aug. 13.

It was a cool and mostly dry week across Iowa. Temperatures were below normal throughout the week except for portions of southern Iowa on Aug. 10 when Donnellson reached 93 degrees. Lowest temperatures were reported on Aug. 8 in the morning when readings fell as low as 45 degrees at Chariton and Grinnell. Temperatures for the week as a whole averaged 4.6 degrees below normal.

No widespread rain in Iowa last week
There were no widespread rain events during the week ending Aug. 13. Showers and thunderstorms brought light to moderate rain to far northwest and northern Iowa (roughly north of a Sioux City to Charles City line) on Aug. 9, with a maximum reported rain amount of 1.04 inches just northwest of Spencer.

Thunderstorms were also scattered across the southeast one-half of Iowa on Aug. 10, with a maximum reported rain amount of 1.3 inches just west of Seymour in Wayne County. There were a few very isolated showers the night of Aug. 6, and Aug. 7 and morning of Aug. 13. Last week the days of Aug. 8, 11 and 12 were dry statewide.

Much of the southeast two-thirds of Iowa recorded no rain during the week. Statewide average rainfall amount was only 0.19 inch, while normal for the week is 0.97 inch. A large area of rain fell on Aug. 14 in the morning across portions of north-central and central Iowa. But this rain occurred too late to be reflected in this report, which provides crop condition and soil moisture statistics for the week ending Aug. 13.