In 2021, Sioux County led all Iowa counties in total corn silage production with 777,000 tons, according to the USDA’s National Agricultural Statistics Service. Winneshiek (505,000), Lyon (492,000), Marshall (315,000), and Fayette (278,000) rounded out the top five highest-producing counties.
Marshall County had the highest yield with an average of 25 tons per acre harvested. Lyon County had the second highest yield at 24.5 tons per acre. Tied for third, at 23 tons per acre, were Fayette, Bremer, and Winnebago.
There were eight counties with a yield of at least 20 tons per acre.
Yields are derived from production divided by area harvested. Only published estimates were considered in rankings of counties.