How did Iowa crops fare in another year of drought?

Background

This year marked Iowa’s worst drought in at least nine years.

Dry conditions have extended across the Mississippi River basin, which was plagued by both extreme rains and extreme drought this year. The Mississippi River reached record lows — grounding barges, stalling crop shipments and spiking shipping costs.

Now, water levels are finally beginning to rise in the Lower Mississippi, and drought conditions are subsiding in Iowa.

According to the latest U.S. Drought Monitor report, about 73 percent of the state is in some degree of drought.

Conditions in Eastern Iowa range from severe drought to no drought. Dry conditions are worse in northwest Iowa, which still is experiencing extreme and exceptional drought — the most intense drought rankings.

Planting in Iowa got off to a late start because of a rainy spring. In July, corn crops fit the “knee high by the Fourth of July” adage, although they typically reach 8 feet by that time of the year.

And by August, scouts labeled state fields “underwhelming” due to dry conditions.

Now, all eyes have turned to how the drought impacted Iowa’s harvest and crop yields.

What’s happened since?

The state’s overall corn production is projected to reach an average of 202 bushels per acre — down only 2 bushels per acre compared to last year, according to a November U.S. Department of Agriculture report.

Soybean production is forecast to reach 59 bushels per acre, which is 4 bushels per acre less than last year.

Rebecca Vittetoe — an Iowa State University Extension and Outreach field agronomist who covers 10 east-central Iowa counties — said each county in her coverage area experienced dry conditions at some point during the growing season.

Her 10-county coverage area encompasses Linn, Johnson, Benton, Jones, Poweshiek, Iowa, Marion, Mahaska, Keokuk and Washington counties.

“South of (Interstate) 80 was impacted a lot more by the drought, and we definitely saw that with the yields this fall,” Vittetoe said.

Last year, she said, yields were higher in the southern part of her coverage area than in the northern part. But this year, yields south of I-80 were lower than average, she said, and yields north of I-80 were normal or better than normal.

Farmers in Linn County were generally pleased with their yields, she said.

Pests, fungus

One of the big issues for corn this growing season was a fungal pathogen called tar spot. It was first found in Iowa in 2015, and it has persisted and spread. If caught early, a fungicide can treat it. Farmers also can plant corn hybrids that are more resistant to the disease.

Linn County was a hot spot for tar spot this year, Vittetoe said.

“Right after Labor Day, I was getting a lot of phone calls about tar spot,” she said. “I could find it in basically any cornfield I went into.”

Farmers apply herbicides at the beginning and end of the growing season to help control weed growth. But there often wasn’t enough rain to activate the herbicides this year, so some fields suffered weeds like water hemp and mare’s tail — though no more than in past growing seasons, Vittetoe said.

In the drier areas south of I-80, crops also endured pests like spider mites and aphids.

Problems with corn rootworms — which produce larvae that feed on corn roots — persisted as well. Afflicted crops are less resilient against major wind or hail storms, which weren’t as prevalent this year.

“Because some of the ways that we manage them, those corn rootworms are getting smarter, and they're developing resistance to our ways for managing them,” Vittetoe said. “We're just having to rethink how we manage that pest a little bit or try different strategies.”

Although the lack of rain raised concerns for crops, it also provided more opportunities for harvesting and fall fieldwork like soil sampling, fertilizer application and seeding cover crops.

Next year

Looking ahead to next growing season, Vittetoe said farmers may want to consider more drought-tolerant hybrids and should plan for higher fertilizer costs.

She said she is also hoping that soil moisture is replenished before the ground freezes this winter. That way, if yet another dry year follows and spring rains don’t come, crops can pull from existing moisture in the ground.

“Think of it like a gas tank,” she said. “I don't want to go into a growing season on the low side. I want to be full.”

How did livestock fare in drought?

Denise Schwab, a beef specialist covering counties in north and east Iowa — including Linn County — for Iowa State University Extension and Outreach, said the drought’s impacts to livestock varied throughout the region.

Farms in the state’s northeast corner and along the Mississippi River fared well, thanks to timely rains that supported hay crops and pastures.

However, farms in the western part of her region dealt with drier conditions. Many pastures, now in their third year of moderate drought, were “looking a little rough,” Schwab said.

Drier conditions usually mean thinner cows, which could lead to calving issues down the line.

Schwab is waiting to hear more reports about pregnancy rates, but the few she has received have held good news. She is awaiting calf weight reports, which she suspects will be decent further north where pastures were greener.

“It sounds like cows bred up pretty well,” she said.

To better adapt to drought conditions, Schwab recommended that producers wean their calves earlier to decrease some of the stress on the cows.

She also said producers “need to be on top of their feed program” this winter to improve cows’ condition and meet nutrient requirements. Stressed pastures also may need to support fewer animals next year.

“Probably the bigger impacts we'll see at calving season next spring, whether the cows are in decent enough condition or if they're still a little thin,” she said.

Brittney J. Miller is the Energy & Environment Reporter for The Gazette and a corps member with Report for America, a national service program that places journalists in local newsrooms to report on under-covered issues.

Comments: (319) 398-8370; brittney.miller@thegazette.com