"One consideration is that we have a crop this year that's not rooted as deep as the corn was last year," points out Elmore. "A shallow root system doesn't help during dry weather as plants can't reach down deep enough to get to the deeper subsoil moisture to carry them through periods when there is lack of rain."
Week ending August 18 was sixth week of the past seven to bring less than normal rainfall
As of August 18, the weekly USDA survey shows 65% of Iowa's topsoil and 59% of the subsoil is short to very short on moisture. "The dry weather remains a concern," notes Iowa Secretary of Agriculture Bill Northey. "While the cool, dry weather was ideal for the Iowa State Fair, crops now need additional precipitation and warm weather as development remains well behind the five-year average."
The complete weekly report is available on the Iowa Department of Agriculture & Land Stewardship's site or on USDA's site. The report summary follows here:
Lack of rain this summer remains a growing concern for many Iowa areas
CROP REPORT: Drier and cooler than average weather persisted across most of Iowa during the week ending August 18, 2013, according to the latest survey by USDA's National Agricultural Statistics Service. Although varying amounts of moisture were received in central and western portions of the state, the lack of significant precipitation remains a growing concern for many Iowa farmers. Statewide there was an average of 6.4 days suitable for fieldwork. Southwest Iowa received the most rainfall during the week, and had the least days suitable for fieldwork with 5.8 days.
A total of 35% of Iowa's topsoil and 41% of the subsoil was in the adequate and surplus moisture categories on August 18, both declining 6 percentage points from the previous week. Topsoil moisture levels are now rated 25% very short, 40% short, 34% adequate and 1% surplus. Subsoil moisture levels are rated 19% very short, 40% short, 40% adequate and 1% surplus.
About 24% of Iowa's corn crop has now reached dough stage, normal is 60%
With nearly all the corn crop tasseled, 93% was silking as of August 18, which is behind the 5-year average of 99%. Sixty-two percent of the corn crop has reached the milk stage, trailing the normal 87%. Twenty-four percent of the crop has reached the dough stage, well behind the normal 60%. Some of the very earliest planted corn has reached the dent stage. Corn condition statewide on August 18 declined slightly from previous week, and is rated at 5% very poor, 13% poor, 34% fair, 40% good and 8% excellent.