The U.S. Justice Department recently launched an antitrust investigation into whether leading commercial fertilizer producers colluded to raise prices.

The companies whose conduct is under scrutiny include phosphate and potash suppliers Nutrien Ltd. and Mosaic Co., as well as CF Industries Holdings Inc., Koch Inc. and Norway’s Yara International ASA, which collectively control most nitrogen-based fertilizer sold in the U.S. and dominate potash and phosphate markets.

The scrutiny comes after the U.S. fertilizer industry underwent dramatic consolidation over four decades. The number of nitrogen fertilizer producers declined from 46 to 13 between 1984 and 2008, a reduction of 72%, according to USDA data. Today, four firms control 75% of the nitrogen fertilizer market domestically, while two firms control nearly 100% of the U.S. potash market


It takes a long time to grow an old friend.