By Robert Pore
robert.pore@theindependent.com

While farmers planted 9.2 million acres to achieve that record production, another factor paying off with greater production is that farmers are planting corn much earlier these days.

According to a new study from the University of Wisconsin-Madison, earlier plantings could account for up to half of the yield gains seen in some parts of the northern Corn Belt since the late 1970s.

UWM Researcher Chris Kucharik said Midwest corn growers produce three times more corn today than they did a half-century ago. He said farmers also sow seeds around two weeks earlier now than 30 years ago.

Kucharik said earlier planting could help explain 20 to 50 percent of the yield gains in the northern Corn Belt states of Nebraska, South Dakota, Minnesota, Iowa, Wisconsin and Michigan since 1979. Meanwhile, the other major factor he considered, climate, seems to have had little impact.

"What I found was that while climate probably has contributed in a small way to the yield trend, the overwhelming contribution has been from this land management change," said Kucharik, an expert on climate and agriculture with the Nelson Institute's Center for Sustainability and the Global Environment (SAGE).

In Nebraska, corn production averaged 822 million bushels with an average yield of 115 bushels per acre.

As concerns about climate change continue to rise, he said scientists are struggling to forecast the potential impacts on the world's ability to grow staple crops like corn.

"This is especially true now, as corn is being increasingly tapped as a feedstock for ethanol production," he said.

But Kucharik said scientists can't lose sight of the role of human decision-making and management practices. He said his study reveals that farmers aren't necessarily planting their crops sooner because of warmer springtime temperatures brought on by global warming.

Instead, seeds engineered to endure the colder and wetter soils of early spring have likely allowed northern farmers to adopt longer-season, and higher-yield, hybrids, Kucharik said.

"Before we jump to conclusions about the impacts of climate change on agriculture, we really need to consider subtle management changes that are taking place and will likely continue to take place in the future," says Kucharik. "Anytime you deal with a system that's being managed by people, it makes for a more complicated story."

Besides climate, Kucharik said researchers have most often attributed skyrocketing yields to technological advances, including mechanization, better crop genetics and pesticides and fertilizers.

But after finding in a previous study of U.S. Department of Agriculture data that Midwest farmers put corn into the ground much earlier now, Kucharik said he pondered the possible impact of this trend.

"I thought, if farmers are planting earlier, that means they're extending the growth period of crops the amount of time plants have to be photosynthesizing, piling on biomass and making grain," Kucharik said. "So it made sense to me that this would have contributed in some way to the yield gains we've seen over past decades."

Whether the trend toward earlier planting can continue is another matter, said Kucharik. He said northern farmers will eventually hit up against frozen ground and other wintry conditions that will be impossible to overcome.

"Especially as we're going through this transition of using corn as the initial feedstock for biofuels, are we thinking that this trend in yields is going to continue indefinitely?" he said. "If planting earlier does contribute significantly in some regions, eventually that effect will wear itself out."