Washington ? The Commerce Department imposed a preliminary 3.9 percent tariff on Canadian wheat imports on Tuesday, deciding the measure may be needed to counter Canadian subsidies of its wheat farmers.

A final decision won’t be made until July. But for now, the ruling requires the Canadian Wheat Board and other exporters to post bonds equal to the preliminary duty on all hard red spring wheat and durum wheat shipped to the United States.

The U.S. wheat groups that sought the tariffs imposed welcomed the decision, although some said the Canadian subsidies are being underestimated.

“Some of these subsidies are cleverly hidden in the policies regulating grain transportation and marketing in Canada, which go hand in glove with the monopoly Canadian Wheat Board,” said Larry Lee, a Velva, N.D., wheat farmer who serves as chairman of the North Dakota Wheat Commission.