According to the United States Department of Agriculture (USDA), the national impact of Hurricane Katrina on Gulf Coast crops was minimal, with most of the damage borne by minor producers of major crops (corn, soybeans, and cotton). The main impact of the storm on agriculture is likely to involve ocean shipping and exports. In 2004, 22% of U.S. wheat exports, 71% of corn exports, and 65% of soybean exports passed through Gulf ports. Shipping did not occur until later in the fall, when ports would again be operational.