MILWAUKEE — Food manufacturing plays an important role in the Wisconsin economy, with sweet corn alone accounting for hundreds of jobs and $130 million in spending, according to a study released Wednesday by the University of Wisconsin-Whitewater.

Wisconsin is the nation's third largest grower of sweet corn for processing, behind Minnesota and Washington. It is the top exporter of processed sweet corn, accounting for 37 percent in 2011, according to the Wisconsin Department of Agriculture.

Russ Kashian, director of UW-Whitewater's Fiscal and Economic Research Center, said one reason for the study was to highlight the importance of food processing in terms of creating non-agricultural jobs.

"Sometimes, it seems like we diminish food manufacturing as 'that's farming,' but that's manufacturing," he said.

Wisconsin farmers, like those nationwide, have been growing less sweet corn over the past 15 years. Kashian said that may reflect a shift to winter wheat and to field corn, which has become more lucrative with the growth of the ethanol industry. Sweet corn is eaten by people, while field corn is used to make ethanol and livestock feed.

Wisconsin farmers harvested about 586,000 tons of sweet corn last year, down from nearly 717,000 in 1997, the report said. Nationally, the harvest dropped from more than 3.3 million tons of sweet corn in 1997 to 2.9 million last year.

"It doesn't diminish the fact that corn is an important crop," Kashian said.

Processed sweet corn accounts for about 320 jobs in Wisconsin, with $21.6 million per year in wages and benefits, the report said. The estimated $130 million per year in economic impact comes when employee spending, plant maintenance, utility and insurance costs and other items are considered.

Most sweet corn is grown in central Wisconsin, with bands stretching south to Rock County on the Illinois border and east to Sheboygan County on Lake Michigan. The study questioned why more of the state's canneries aren't located in Portage and Waushara counties, which are major areas for growing sweet corn but have few known processing plants.

The report comes less than a month after Seneca Foods Corp. announced a planned expansion in Janesville, with up to five new production lines. The company has told the city it will add at least 25 new jobs and perhaps as many as 78.

If anything, the study may have underestimated the value of sweet corn to the state economy. Wisconsin has 31 licensed processors who can or freeze vegetables, according to the Department of Agriculture, Trade and Consumer Protection.

Kashian said the report focused on those that can corn because most canneries handle a few vegetables, making it possible to separate the impact of corn from that of peas, sauerkraut and other items. Frozen vegetables have become more popular, but plants that produce those often handled other foods such as fruit or French fries, making it harder to separate one item's importance from another, he said.