Fall Drought Continues, Threatens Next Year's Yields

Fall Drought Continues, Threatens Next Year's Yields

Drought conditions in Iowa have worsened; rain is needed soon to begin replenishing subsoil moisture reserves for 2013 crops.

The 2012 drought that struck Iowa and the rest of the Corn Belt this summer has grown worse, raising more concern about the 2013 crop growing season. According to the latest U.S. Drought Monitor map released by the National Weather Service on October 4, the epicenter of the drought has moved westward from Indiana and Illinois and is now in Iowa.

DRY OCTOBER: A new month is not likely to bring relief from very dry conditions in Iowa, according to the latest National Weather Service forecast. Through the end of September only a few small areas of Iowa had received near normal rainfall for the month, while numerous locations received less than half the normal amount, continuing a trend set during the three summer months.

The map shows that as of last week, 75.3% of the state of Iowa was in extreme drought, up from 65.8% a week ago. State climatologist Harry Hillaker with the Iowa Department of Agriculture says to be effective in replenishing soil moisture in the top 5 feet of soil, rains need to fall by December 1, 2012. That's about when the usual freezing of Iowa's soils occurs for winter. After the ground freezes hard, rainfall and melting snow run off the fields instead of soaking into the fields.

"Moisture generally runs off of frozen ground," notes Hillaker. "The clock is ticking. We need some rain soon to build up the supply of reserve moisture in the subsoil for use by next year's crops."

Iowa's rainfall for 2012 through September is running 9.12 inches below normal

The cool front that dropped temperatures into the low 50-degree range late last week failed to bring much rain to the state. There were a few sprinkles in areas of Iowa but "the state's drought is persisting during the fall season, which is a crucial time to start to get some rain to replenish the soils that have been dried out by hot, dry weather we had this past summer," notes Hillaker.

Iowa's rainfall through the end of September totaled 20.57 inches which is 9.12 inches short of the 29.69 inches that's normal through the first nine months of the year. The 9.12 inch moisture deficit is the eighth largest on record in Iowa history, says Hillaker.


Despite the continuing dry conditions, Iowa is still likely to top the total rainfall of the last severe drought, which was 1988, when just 21.65 inches fell during the entire year. Iowa's normal annual precipitation is 35.27 for the statewide average.

USDA estimate for 2012 crop yields and production to be released October 11

In Illinois which has suffered all summer, only the northwest corner of that state is now in the "severe" drought category, and the rest of the state is merely rated "dry," according to the latest drought map. The crop-crippling drought through June, July and August has hurt the corn crop in that state, normally the No. 2 producer behind Iowa, and has left it with a corn crop that last week was rated by USDA as 75% poor to very poor. Iowa's corn crop last week was rated 47% poor to very poor.

USDA's next monthly crop production report will be released October 11 and will give an update on the official yield estimates for corn and soybeans for the U.S. and for individual states. The October Crop Production Report is based on in-the-field surveys conducted around October 1 by USDA enumerators. Despite the continuing drought, farmers in some areas of Iowa say they are pleasantly surprised this fall, as corn and soybean yields in some of their fields are turning out to be better than they expected, considering how hot and dry it was in July and August.

The commodity consulting firm FCStone last week estimated total U.S. corn production for 2012 at 10.824 billion bushels, with a yield average of 123.9 bushels per acre. That projection is a better forecast than USDA's September estimate for a national corn yield of 122.8 bushels per acre and a production 10.727 billion bushels. FC Stone estimated soybean yields for the U.S. last week at 38.2 bushels per acre with a total crop size of 2.849 billion bushels. USDA in its September report estimated the U.S. soybean average yield at 35.3 bushels per acre and production at 2.634 billion bushels for 2012.

Meanwhile, looking ahead to next year's crop, "We definitely need a recharge on soil moisture statewide, and we need it soon," says Roger Elmore, an Iowa State University Extension agronomist.

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