The growth in grain farms came even as Wisconsin lost dairy and other types of farms.
The changes were detailed Friday in information from the 2012 Census of Agriculture. The U.S. Department of Agriculture conducts the count every five years to gather information on the nation's farms and the people who run them.
The latest census found fewer, larger farms in Wisconsin than five years earlier, a trend seen nationwide. Milk remained the state's most valuable product, accounting for nearly $5 billion of the state's $11.7 billion in agricultural sales in 2012. Grain sales doubled from $1.6 billion 2007 to nearly $3.4 billion in 2012, with much of the gain coming from the increased value of corn.
Wisconsin had about 69,800 farms in 2012. That's about 8,700 less than in 2007, when the previous census was done. Data released earlier this year showed the state also lost about 620,000 acres of farmland.
The Department of Agriculture, Trade and Consumer Protection said Friday that much of the loss could be explained by sales of woodland that farmers weren't tilling and decided to no longer keep. Florence and Vilas counties, on the border with Michigan's Upper Peninsula, saw the largest decreases in farm acreage.
"While no one likes to see the decrease in the number of farms and land in farms, it represents the evolving agricultural industry," DATCP Secretary Ben Brancel said in a statement. "There are several trends we'll look for as we analyze these numbers such as neighbors and multiple families combining farms to develop efficiencies or acreage in production through a rental or lease agreement rather than sole ownership. Land may have been repurposed from agricultural production to recreational use."
The number of dairy farms shrank by 20 percent from about 13,000 in 2007 to roughly 10,400 in 2012, reflecting continued consolidation in the industry. The census considers a farm a dairy farm if its main business is producing milk. About 1,500 other Wisconsin farms also had at least one dairy cow in 2012.
The state added about 20,000 dairy cows even as the number of farms shrank, bringing the population to nearly 1.3 million animals. About 30 percent of the herd is kept on nearly 400 farms with 500 or more cows each.
Yet at the same time, most of the state's dairy farms remained small, with less than 100 cows.
The number of farms that earned most of their income from grain increased 46 percent from 13,500 in 2007 to 19,700 in 2012. DATCP spokesman Jim Dick said the reason for the increase wasn't immediately clear, but one explanation might simply be that farms that once made more money from beef or milk saw the value of their grain soar when corn and soybean prices jumped around the time of the census.
The USDA categorizes farms by their most valuable product.
Wisconsin saw a 4 percent increase in sheep and goat farms amid growing demand for goat cheese. Nationwide, the number of dairy goat farms increased from nearly 27,500 in 2007 to more than 29,500 in 2012. Wisconsin had 994 farms with 44,500 dairy goats, the largest herd in the nation in 2012. The USDA did not provide a state-by-state breakdown in 2007.