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Drought Monitor ranks parts of Iowa abnormally dry

By Staff | Jul 28, 2017

The lack of rain and recent high temperatures has many producers concerned about how those conditions will affect yields.

Elwynn Taylor, Iowa State University Extension climatologist said the U.S. Drought Monitor, released July 20, indicates there are two early stages of drought present in the state.

These early stages listed include abnormally dry and moderate drought conditions.

While he said these early stages don’t necessarily call for any reduction in yields below the state average, if conditions continue to worsen, there may be an increased cause of concern.

“It’s when it gets up to the third stage and above you will expect below average yields,” said Taylor. “If it doesn’t get any worse, it hasn’t precluded Iowa from having normal, at least, yields of corn and soybeans.”

The days following the July 20 U.S. Drought Monitor report, Taylor said, brought some precipitation to areas in the state that necessarily did not need any moisture.

“Heavier than desirable rains fell in some areas of extreme southwest and northeast Iowa,” he said. “Everywhere else could have used more.”

One factor that could be affecting crops, especially corn, is how the beginning of the growing season began, according to Taylor.

“The moisture in the soil was very good to excessive at the beginning of the year. The places that were excessive, some planting was done under the conditions of too much moisture in the soil,” he said. “In many cases, that resulted in a compromised root system – making some fields more susceptible to warm/dry conditions.”

However, he added uncertainty seems to be increasing in people’s minds, as July is the most important month for favorable weather conditions for the corn yields. Taylor said August, historically, has been the month for soybeans.

July, he said “didn’t make a perfect show in very many Iowa locations, but the state has, by no means, lost its possibilities of having crops that are at least as good on average if not better.”


Taylor said the forecast is only giving a few hints of how the weather may be progressing for the state of Iowa.

“One hint is, since the forecast outlook weather pattern seems to be hot and dry in the Canada/U.S. border, that pattern also indicates favorable conditions for the bulk of the Corn Belt,” he said. “In other words, the bulk of the Corn Belt is in very favorable conditions when the Montana/North Dakota/adjacent Canada area having adversely hot and dry conditions. That is bad news for them. But not bad news by any means, potentially, for the Corn Belt.”

Taylor concluded that the conditions that we have tend to produce an unstable marketing world.

“Buyers and sellers of grain are often reacting because of apprehension. Or some people call it a scare,” Taylor said. “This type of year typically brings three scares. We just had the first one. Beans do the same thing. You can say it is more than usual in years that are similar to this we have three significant price scares in the corn and soybean market before harvest. And we had one, of course, in July.”

Paul Kassel, ISU Extension field agronomist, serves Buena Vista, Clay, Dickinson, Emmet, Hancock, Kossuth, Palo Alto, Pocahontas, Sac and Winnebago counties.

He said looking at the drought monitor that he expected more counties to be listed dryer than they were.

“The latest drought monitor sums it up for my area,” said Kassel. “Except I expected to see parts of Buena Vista, Clay and Palo Alto under the moderate drought category, but those areas are listed as only ‘abnormally dry.'”

The recent dry weather conditions, Kassel said, has most likely had some impact on the corn crop.

“It is likely the top end of the corn yield potential has been damaged,” he said.

Although parts of his coverage area did receive some rain late last week and over the weekend, Kassel said it just wasn’t enough.

“We are going to need about an inch of rain a week for the next six weeks to minimize further yield losses,” said Kassel.

As far as soybeans, he said they seem to look good.

“It is too early to get real concerned on yield damage to the soybean crop,” he said.

Pests don’t seem to be invading many acres in the counties he serves and he added that there have been some herbicide issues.

“Dicamba drift issues has been the largest issue outside of the dry weather,” said Kassel.

Mark Johnson, ISU Extension field agronomist, serves Boone, Carroll, Dallas, Greene, Jasper, Marshall, Polk, Story and Warren counties.

He has been out of the area since mid-July, but said at that time his area was seeing little disease or insect pressure in corn and soybean fields.

However, he said dry conditions have been present since about May 24.

In the July 20 drought monitor map, Johnson said of the nine counties he serves, Carroll, Greene, Boone, Story and Jasper are mostly in the moderate drought category, with the rest of the counties put in the abnormally dry category.

“We entered the season with a good soil water profile and roots were not limited by saturated soil conditions during June, so they were able to explower a lot of cubic feet,” said Johnson. “As a result, only sandy or compacted areas of fields are looking tough so far.”

Johnson said cooler temperatures, especially at night, are needed.

“However, pollination and kernel fill are high demand time periods and when we have hot nights, the plant respire a lot of energy,” he said. “That is energy that does not go to fill the kernels. Having said all that, if we continue to be hot and dry, it will have a real impact on kernel fill.”

“Hopefully we can get back to more reasonable temperatures, especially night time temps and get back to more normal rainfall,” he added. “If both happen we will get good yields.”

Johnson also said yields will most likely not top 2016, but good yields are still a very real possibility.

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