Despite a wet and delayed planting season, Iowa’s 2019 corn crop has made headway in crop maturity, thanks to some warm temperatures in July. USDA’s weekly survey for the week ending July 28 shows 69% of the state’s corn crop is now in the silking stage, 13 days behind last year and only 8 days behind the five-year average. The survey shows 65% of Iowa’s soybean crop has started to bloom, 13 days behind last year and 10 days behind average.

USDA says 58% of the nation’s corn crop is now in the silk stage, compared with 83% for the five-year average. The U.S. soybean crop is 57% blooming, compared to a five-year average of 23%.

“Farmers across most of Iowa enjoyed several days of near-perfect weather last week,” notes Iowa Ag Secretary Mike Naig. “Corn development is in various stages. The earliest planted corn is almost done pollinating, while some fields that were delayed because of wet spring conditions are just starting to tassel.”

The weekly Iowa Crop Progress and Conditions Report is available on USDA’s site at nass.usda.gov/ia.  

Crop report

This past week brought below average temperatures and little to no rain across much of Iowa as farmers had 5.9 days suitable for fieldwork during the week ending July 28, according to USDA’s National Ag Statistics Service. Fieldwork included scouting, spraying fungicides and insecticides, and harvesting hay and oats.

Topsoil moisture is rated 4% very short, 21% short, 71% adequate and 4% surplus. Districts in the southern third of Iowa and the east central district reported topsoil moisture conditions as over 40% short to very short. Some counties in those districts were also rated as abnormally dry for the first time this season according to the July 25, 2019, U.S. Drought Monitor. Subsoil moisture was rated 2% very short, 14% short, 79% adequate and 5% surplus.

As of July 28, the survey shows 69% of the Iowa corn crop has begun to silk, 13 days behind last year and 8 days behind the five-year average. It shows 7% of the crop has reached dough stage, nearly one week behind both last year and average. Corn condition is rated 65% good-to-excellent.

Looking at soybeans, 65% of Iowa’s crop has started to bloom, 13 days behind last year and 10 days behind average. And 13% of the crop has started setting pods, nearly two weeks behind average. Soybean condition is rated 62% good-to-excellent.

Iowa’s oat crop is now 94% in the “started coloring” stage, two days behind last year and two days behind average. Combines made progress last week as 39% of the oat crop has been harvested for grain, six days behind average. Oat condition is rated 63% good-to-excellent.

Second cutting of alfalfa hay reached 76%, six days behind average. A third cutting of alfalfa hay has already started with 2% complete statewide. Hay condition is rated 62% good-to-excellent. Pasture condition declined for the fourth straight week with 56% good-to-excellent. Cooler temperatures this past week helped improve livestock conditions.

Weekly weather summary

Iowa experienced a less active weather pattern during the week ending July 28, with multiple days in which rainfall was largely absent from the state.

“With less thunderstorm activity, unseasonable dryness was reported across Iowa,” says Justin Glisan, state climatologist with the Iowa Department of Agriculture. “Cooler than normal conditions also prevailed with average temperatures up to 5 degrees below normal in western Iowa. The statewide average temperature was 71.9 degrees, 1.5 degrees below normal.”

Showers and isolated thunderstorms moved out of Iowa through the rest of Sunday (July 21). Light but measurable rain fell across parts of western and southern Iowa, where totals were highest; Red Oak (Montgomery County) had 0.32 inch while Rathbun Dam reported 0.18 inch. High temperatures were generally in the 70s with a statewide average high of 78 degrees, 6 degrees below normal.

Unseasonably cool temperatures continued into Monday under clear conditions and northerly flow. Dry conditions also prevailed as high pressure dominated. Overnight lows into Tuesday dipped into the mid-50s, up to 12 degrees cooler than average. Dry and pleasant conditions continued through the day under partly cloudy skies.

Highs reached the upper 70s and low 80s, continuing the unseasonable coolness; there were no reports of measurable rainfall. Wednesday (July 24) was a rain-free day across Iowa as temperatures started to approach more seasonal marks; eastern Iowa reported highs in the mid-80s while western Iowa was 2 to 4 degrees below average.

Showers and a few thunderstorms moved through Iowa most of Thursday leaving measurable rainfall across the state. Highest totals were reported across northern Iowa; Rock Valley (Sioux County) received 0.23 inch while Forest City (Winnebago County) reported 0.46 inch. West-central Iowa also picked up totals between 0.16 inch at Mapleton (Monona County) to 0.30 inch in Denison (Crawford County). Cloud cover and rainfall kept highs 10 to 15 degrees below average in northern Iowa with the average statewide temperature at 80 degrees, 5 degrees below normal.

Friday saw temperatures rebound with a southerly wind and clear skies. Dry conditions also prevailed into Saturday for much of the state, though a narrow band of showers extended from central to eastern Iowa, generally along the I-80 corridor.

The northwest quadrant of Iowa also reported showers in advance of a cold front. Rainfall totals at 7 a.m. on Sunday (July 28) ranged from 0.03 inch at Sioux City (Woodbury County) to 0.36 inch in Traer (Tama County). Daytime highs on Saturday were in the mid-to-upper 80s with a statewide average of 88 degrees, 4 degrees warmer than normal.

 Weekly rainfall totals ranged from no accumulation at De Witt (Scott County) to 0.55 inch at Underwood (Pottawattamie County). Statewide weekly average precipitation was 0.13 inch, well below the normal of 0.97 inch.

The week’s high temperature of 91 degrees was reported on July 27 in Ankeny (Polk County), Donnellson (Lee County) and Newton (Jasper County), 5 degrees above average. Atlantic (Cass County), Denison (Crawford County), Little Sioux (Harrison County) and Mapleton (Monona County) had the week’s low temperature of 50 degrees on July 23; 13 degrees below average.