The Court of International Trade is considering an appeal against the U.S. International Trade Commission’s decision to place duties on phosphorous fertilizers from Morocco and Russia.

The National Corn Growers Association says that has put fertilizer companies under scrutiny this week. “We’ve been sounding the alarm for a long time and telling officials these tariffs are hurting farmers,” says NCGA President Chris Edgington. “We finally have seen results as a judge with the Court of International Trade began asking tough questions about the assertions made by fertilizer companies.”

The appeal comes after the Department of Commerce and the International Trade Commission ruled last year in favor of a petition by U.S.-based Mosaic to impose duties on phosphorous fertilizers imported from Russia and Morocco.

Mosaic claimed the imports were unfairly subsidized and undercutting prices in the U.S. Decisions from the ITC and the Court of International Trade are expected later this summer.