Soaring energy prices will yield sharp increases for corn and soybean production next year, cutting into farmers’ profits and stretching already high food costs, according to a new University of Illinois study.

Costs to get crops in the ground will jump by about a third in 2009, fueled by fertilizer prices expected to surge 82 percent for corn and 117 percent for soybeans, said Gary Schnitkey, an agricultural economist who conducts the annual survey of input costs.

Fertilizer – the biggest non-land expense for corn and soybean farmers – is tethered to the same cost spiral that has driven steep gasoline and heating price increases over the last few years, said Schnitkey, a professor of agriculture and consumer economics.

“Roughly 80 percent of the cost of producing nitrogen fertilizer is natural gas, so as natural gas costs have gone up so have the costs of those inputs,” he said. “Phosphorus and potassium are mined, and as energy costs increase, mining costs increase.”