Early droughts hinder crops, worry farmers

WASHINGTON — A widespread drought has likely already taken a toll on Iowa’s crop production, according to state experts and farmers.

For the week ending June 25, the USDA’s Crop Progress and Condition Report said over two thirds of fields reported topsoil and subsoil moisture conditions of “short” or “very short.” Less than a third of hay conditions were rated “good to excellent” for the week, as were less than a quarter of pasture conditions. While corn and soy fared slightly better (56% and 48% good to excellent, respectively) the numbers were still down from their 80% ratings at the same time last year.

Sweltering temperatures haven’t helped matters. Washington County set the statewide high on June 24 at 95 degrees, a number State Climatologist Justin Glisan said was 12 above normal in the week’s Crop Progress and Condition Report.

The U.S. Drought Monitor update released on June 29 shows most of Southeast Iowa in a D2-class “severe drought.” Things are slightly better in the northern reaches of Muscatine, Mahaska, Johnson and Keokuk counties, experiencing only a “moderate drought,” but worse in most areas of Wapello, Davis, Jefferson and Van Buren counties, labeled with “extreme drought” conditions.

Iowa State University Extension Office Field Agronomist Rebecca Vittetoe said the drought itself wasn’t especially unusual, but that its timing was. May and June are usually the rainiest part of the growing season for corn and soybeans.

While late-season showers could still help turn things around, Vittetoe said yield potential was already capped by poor early-summer conditions.

“We still have a window, yet, where if we do get some rain consistently throughout the growing season here, it’s not all doom and gloom,” she said. “But we’re going to need consistent rainfall … some of that top end’s already been taken off.”

As a rule of thumb, corn needs roughly 21 inches of precipitation to flourish during its growing season, according to Vittetoe. Not all of that needs to come from the sky, however; Plants can usually tap reserve moisture stored in the soil from previous seasons.

Thanks to another drought in 2022, however, Vittetoe said those reserves were starting to run dry. The result is corn with rolled leaves and beans sitting shorter than in most years.

“We’re relying pretty heavily on that moisture that’s in the soil for our crops to be able to grow,” she said. “The more limited that gets, obviously, that’s going to put more stress on the crops. And looking out on the fields, you can see some of that, especially in the areas that have missed some of that rainfall.”

The lack of moisture has also complicated herbicide usage, as hot conditions favor hardier weeds and stymie preventive soil treatments.

“They get more of a waxiness on their leaves … and those weeds kind of harden off,” Vittetoe said. “We’ll use residual herbicides so that as the weeds germinate, they’re out there working to kill the weeds. But with the drier spring, some of those residuals didn’t get activated … so we saw some weeds sneaking through.”

  Buy Photo

Where it has rained, it’s been spotty. Growers have seen showers pass through some fields while others nearby go without a drop. Lindsay Greiner, a corn and soybean farmer in Keota with 45 harvests under his belt, said the difference was plainly visible.

He said growers were now at the mercy of mother nature.

“You get to this point in the growing season, and you’ve done about everything you can do for the crop,” he said. “We just need rain to make this crop decent. So if it stays dry, it’s not going to be good.”

Still, the Keota farmer said it was too early to tell exactly how current conditions will translate to yields later this year. He said modern crops were more resilient than those lost to severe droughts in the ‘80s, which means predictions based on past experience come with a grain of salt.

Even so, the plants still need water, one way or another.

“We’ve found out in the last four or five years that we can raise a pretty good crop on less rain than we used to, with the genetics we have nowadays,” Greiner said. “But if you’re not going to get much rain, you really need it at the right times. Pollination’s going to start for our corn crop probably in the next two weeks, and that’s a time when our corn crop really needs rain. Soybeans are probably starting to flower now.”

Producers using cover crops are facing mixed results, according to Continuum Ag President and CEO Mitchell Hora, who said his soil remained microbiologically healthy but still dry. His rain gauge has measured just 0.55 inches since the first week of May.

Hora said his farms’ cover crops had soaked up some of the ground’s precious moisture reserves before planting began, but left behind biomass that protected the dirt from evaporation once temperatures rose. He added that an early planting time, around Easter weekend in April, had helped many of his plants thrive.

“That residue helps to keep the sunlight away from that soil,” he said. “On my own farm, we can have a 90-degree day, but under the residue, we could still be at a very comfortable mid-70s … but I tested bare soil, where there was no residue, and it was 126 degrees. So that residue helps to provide the armor so we can avoid too much evaporation, and also keep our soil temperature in check.”

Still, Hora said fields with the most aggressive cover cropping had performed much worse, running on even less reserve water than the others. As a rule of thumb, the later cover crops were killed off, the worse the remaining soil fared under drought conditions.

Even so, starting around 10 inches deep, he said subsoil moisture conditions were workable as of June 1, something he cited as evidence of the practice’s implications for long-term farm resilience.

“It would have been great to kill our cover crops this year even earlier than what we did, however, we can’t predict the weather,” he said. “Being an abnormally dry year, it just dinged us. In every other year, it’s been amazing.”

In the Haskins area northeast of Ainsworth, farmer Dave Skubal said his crops faced the same hardship as anywhere else, but that his biggest concern at the moment was cattle pastures.

Weeks before the first day of summer, he was already tapping into winter’s food supply as grazing fields dried up. While he can stretch the remaining hay with chopped corn silage after this year’s harvest, the extra work needed to do so will be tedious at best.

“Usually, our pastures, by August or so it’ll dry up and we have to haul feed and water to them, but this year we were doing it by the first of June,” he said. “We never usually haul feed and water that early in the year. It’s going to be a long summer.”

Comments: Kalen.McCain@southeastiowaunion.com