The first week of May is traditionally thought of as the ideal time for Iowa farmers to begin planting, but a slow start to spring and volatile grain markets in recent weeks have left producers with a lot of questions, agronomy and grain markets experts at Iowa State University said.
Excessive moisture, especially in the eastern half of the state, and a cool spring may keep farmers out of the fields for a while longer, said Elwynn Taylor, a professor of agronomy and an ISU Extension and Outreach climatologist.
Taking heavy farm machinery into the fields while they're too wet can cause the soil to become compacted, which makes it more difficult for crops to develop a strong root system, Taylor said. Waiting until the soil dries out may be the prudent decision, but waiting too long shortens the growing season and can lessen yields when harvest comes around, he said.
"So that first week of May is historically the best and ideal time to plant," he said. "People realize that, and they'll do so but only if the conditions are right."
A look ahead
Taylor said predicting the weather for an entire growing season is a tricky business, but studying past weather cycles can offer a few clues that may point toward below-trend-line yields this year. For instance, the La Niña event that has just ended was the second strongest in history. It began in July 2010 when the Pacific Ocean off the west coast of South America cooled significantly and ended in 2012, but the weather pattern it influenced was still apparent into 2013. History shows the fourth year after the beginning of such a strong La Niña usually produces lower-than-expected yields in Iowa, Taylor said. La Niña events are usually associated with a severe drought similar to what Iowa experienced last year, he said.
"During the five events that have been similar to what we've seen the past three years, the fourth year was a below-trend yield year," he said. "So all we're looking at is what's happened before when we had similar circumstances."
Taylor said this year is shaping up like 1947, in which a wet and cool spring kept crops from developing sufficient roots systems to handle the hot and dry conditions that came along in late summer. That year ended with yields that were as bad as those experienced during the Dust Bowl. The sooner the weather pattern shifts away from similarity to 1947, the better, Taylor said.
Grain markets have shown volatility in recent months, adding more uncertainty for farmers, said Chad Hart, an ISU Extension and Outreach grain markets specialist and associate professor of economics.
The price of corn dropped about 80 cents in early April but jumped 40 cents early last week. Planting delays account for at least some of the ups and downs in the market.
"The market is ready to make a run, but it doesn't know which direction to go yet," Hart said.
American farmers are expected to plant 97 million acres of corn this year, according to the most recent surveys. That's an increase of about 100,000 acres over last year, Hart said. If yields are close to trend-line or above, it would likely be a record harvest, he said.
Although farmers may be growing a bit antsy to begin planting, the price of corn in recent weeks is still healthy and allows for profit.
"Even with all the uncertainty, farmers are still seeing a good price for corn on average," Hart said. "So there's some cause for optimism in the middle of all this volatility in the market."
Explore further: Signs for optimism as harvest reaches peak in Iowa