Is early corn planting worth the risk?

Farmers who were able to plant corn early this spring could see a big benefit come pollination time, according to a new report released this week by The Climate Corporation. But the advantages of early planting are likely to be sharply divided between the eastern and western Corn Belt. And in large parts of the region, planting super early may not be worth the risk.

Warm weather in early spring enabled many farmers to plant at “some of the earliest dates ever seen,” said Jeff Hamlin, director of agronomic research at The Climate Corporation.  By May 13th of this year Ohio farmers had planted 78% more corn acres than they had in 2011 and in South Dakota this year, the pace was 43% head of last year.

In his work Hamlin searched through thirty-two years of  weather data to discover whether the benefits of planting early offset the risks that can come with it.

Historically, early planting has been of little yield benefit to corn producers in most of Minnesota, Wisconsin, Michigan, Ohio and northern Iowa, according to the study. The increased risks there, including greater chances of a spring freeze of poor seed germination, “would more than offset any expected benefits related to an earlier pollination period,” Hamlin said.

But, in Kansas, Missouri, Nebraska, and South Dakota, farmers planting early and gaining an earlier pollination period by even a week could reduce the chances of a heat-related yield decline by up to 40%.

A 'HOT WEEK' AHEAD?

In studying the impact of heat on corn pollination, Hamlin established that the week of July 15-21 has typically been the warmest in the eleven Corn Belt states. He developed the idea of a “Hot Week,” one in which temperatures rise to 95 degrees F. or above for two or more days.  The question is how much value is there to early planting and pollination outside of the July 15-21 period.

In the northerly/ eastern Corn Belt areas, early planting typically didn’t help much with the heat.

“Even when growers in those regions plant corn early enough that it pollinates four weeks ahead of the worst pollination week (July 15-21), they see a significant temperature benefit in less than one out of twenty years,” Hamlin said.

In contrast, growers in the western/southerly states have historically seen a significant reduction in their risk of heat stress during corn pollination for each week they can advance the pollination period earlier than the week of July 15-21. In this region the benefit starts with even a one-week advance.

While the study only looked at the one factor of heat on pollination, Hamlin pointed out that growers have other motivations for planting early: avoiding dry weather, use of a longer season hybrid, size of operation, and marketing of new crop corn.