Iowa Corn Crop Keeps Deteriorating

Iowa Corn Crop Keeps Deteriorating

Condition of Iowa's 2011 corn crop slipped again last week, due to continued dry weather. Rating went from 63% "good to excellent" down to 59% as of August 28 in statewide survey.

Iowa's 2011 corn crop took it on the chin again last week due to continued dry weather. It slipped from a 63% good-to-excellent" rating the week before to 59% good-to-excellent for the week that ended August 28.

That's according to the weekly statewide survey released August 29 by the Iowa office of USDA's National Ag Statistics Service in Des Moines. Nationally, this year's corn crop fell from 57% good-to-excellent the previous week to 54% for the week ending August 28.

The good-to-excellent rating for the 2011 Iowa soybean crop rose from 63% the previous week to 64% as of August 28. But crop reporters who participate in the statewide weekly survey still expressed concern about dry conditions during the critical pod filling stage for soybeans in August. Most of the state would like to get some rain to help with pod fill and relieve stress on other crops, the report stated.

Five weeks of below average rainfall has stressed Iowa's crops

Iowa Secretary of Agriculture Bill Northey says "the dry weather and destructive storms are continuing to affect crop development this year and cause concern for farmers as harvest is quickly approaching."

Iowa's crops this summer were stressed first this summer by the hottest July weather since 1955 and then by five consecutive weeks of below-average rainfall. State climatologist Harry Hillaker says several areas of Iowa, especially southeast and central Iowa, are now classified as drought-stricken. Much of the rest of Iowa is categorized as "abnormally dry."

Hillaker says Iowa's statewide average precipitation was 0.73 inches last week, while normal for the week is 0.93 inches. "This was the fifth consecutive week of below normal rainfall," he notes.

Running ahead of normal, 92% of Iowa corn has reached dough stage

The weekly Iowa Crop & Weather Report is available on the Iowa Department of Agriculture website at or on USDA's site at  Here's a summary of the latest survey results:


Iowa Crop Conditions as of Aug. 28, 2011

                                   This Week                Last Week

                   Fair       Good      Excellent        Excellent

Corn           26%        45%          14%               25%

Soybeans   24%        45%          17%               17%

Iowa's average temperature for week ending August 28 was 73.4 degrees F, which was 1.9 degrees above normal. Average rainfall was 0.73 inch, 0.20 below normal. High winds and hail again affected crops in northwest, north central, west central and southwest Iowa. Most of the state needs some rain to help beans fill their pods and to relieve stress on other crops caused by five weeks of below-average rainfall. Nearly all of Iowa's 2011 corn crop has now reached milk stage, and 92% is at dough stage, ahead of the 5-year averages. Nearly all of Iowa's soybean crop has now set pods.

Private survey pegs U.S. corn yield at 148 bushels, Iowa at 164 bushels

Last week private surveys across the Corn Belt estimated the U.S. corn crop this year at 148 bushels per acre, down from USDA's August 11 Crop Report estimate of 153 bushels per acre. For Iowa, the private survey says the state's corn crop this year will yield an average of 164 bushels per acre, down from the 177 bushels predicted by USDA on August 11. Iowa's corn crop yielded 165 bushels per acre in 2010 and 182 bushels per acre in 2009. Iowa is the largest corn producing state, accounting for about 20% of the nation's corn production.

For soybeans, the private survey conducted last week says the national yield average will be 41 bushels per acre this year, down from 43 bushels per acre forecast by USDA on August 11.

High winds and hail have again affected crops in parts of Iowa

In the weekly Crop & Weather Report issued August 29, northwest, north central, west central and southwest Iowa all reported having areas damaged by high winds and hail last week.  Most of the state needs some rain to help bean pods fill and to relieve stress on other crops.  Areas in southeast Iowa as of August 29 reported receiving less than an inch of rain since the end of June. Corn silage harvest is already underway in many areas. 

There were 5.9 days suitable for fieldwork statewide during the past week in Iowa. Southeast Iowa led the way for the second straight week with all 7 days suitable while southwest Iowa had only 4.6 days suitable. Topsoil moisture rated 19% very short, 33% short, 46% adequate and 2% surplus on August 28. Subsoil moisture rated 13% very short, 35% short, 50% adequate and 2% surplus. 

Four percent of Iowa corn is now mature, compared to 10% last year

Nearly all the state's corn crop has reached milk stage and 92% has reached dough stage, behind last year's 93% but ahead of the 5-year average of 81%.   Iowa's corn crop is 70% at or beyond the dent stage, an increase of 29% from the previous week and 20% ahead of normal. About 4% of Iowa's corn crop is now mature, behind last year's 10% and the normal 5%.  Corn condition stands at 5% very poor, 10% poor, 26% fair, 45% good and 14% excellent. 

Nearly all the state's 2011 soybean crop is setting pods. As of August 28, only 4% of Iowa's soybean fields are turning color, trailing last year's 15% and the 5-year average of 11%. Soybean condition is reported at 4% very poor, 8% poor, 24% fair, 47% good and 17% excellent. 

As of August 28 third cutting alfalfa hay harvest advanced to 71% complete, ahead of last year's 67% and the normal 60%. Condition of the Iowa hay crop is reported at 8% very poor, 17% poor, 30% fair, 38% good and 7% excellent.

Pasture and range condition as of August 28 rated 9% very poor, 21% poor, 33% fair, 30% good and 7% excellent. Moderate conditions continue to be favorable for livestock. The need to supplement with hay due to short pastures has already raised concerns for next spring's hay supplies.


IOWA PRELIMINARY WEATHER SUMMARY—for week ended Aug. 28, 2011

By Harry Hillaker, state climatologist, Iowa Department of Agriculture & Land Stewardship

The work week began with thunderstorms moving across the southwest one-quarter of the state on Monday (Aug. 22) morning with one to two inches of rain falling in the far southwest. Tuesday (Aug. 23) morning saw more thunderstorms with some one to two inch amounts over the northeast one-third of Iowa. Some of these storms brought large hail and high winds. Wednesday and Thursday were dry while there were a few light rain showers over the southwest one-half on Friday (Aug. 26). Saturday was dry while there were scattered mostly light rain showers and thunderstorms over much of the state on Sunday (Aug. 28). 

Some southeast Iowa locations again failed to record any rain this past week with Oskaloosa, Washington, Fairfield and Keokuk among the dry spots. Anamosa reported the most rain for the week with 4.30 inches. The statewide average precipitation was 0.73 inches while normal for the week is 0.93 inches. This was the fifth consecutive week of less than normal rainfall.

Temperatures were above normal except on Thursday and Sunday. Highs reached into the 90s in many areas on Tuesday and Wednesday but were only in the 70s on Sunday. Temperature extremes varied from Wednesday afternoon highs of 99 degrees at Keosauqua and Donnellson to a Thursday morning low of 46 degrees at Battle Creek (Ida County). Temperatures for the week as a whole averaged 1.9 degrees above normal.

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