U.S. corn inventories on March 1 jumped more than forecast to the highest level since 1987, adding to prospects for ample supplies that have eroded prices the past 12 months, a government report showed.

Farms and warehouses held 7.745 billion bushels of corn to start this month, up 10.5 percent from 7.008 billion a year earlier, the U.S. Department of Agriculture said Tuesday in a report after surveying grain companies and farmers. The average estimate of 30 analysts in a Bloomberg survey was 7.609 billion.

Bigger global grain and oilseed supplies have helped drive world food costs to the lowest since 2010, with the Bloomberg Grains Subindex dropping more than 25 percent in the past year. A glut of corn, used in everything from animal feeds to alternative fuels, may signal lower costs for meat producers including Tyson Foods Inc. and for makers of sweeteners and ethanol such as Archer-Daniels-Midland Co.

Corn futures have tumbled about 20 percent in the past year on the Chicago Board of Trade, closing Monday at $3.945 a bushel after farmers produced two consecutive years of record crops. The United Nation’s food index declined in February to the lowest since July 2010 amid bumper global harvests of wheat, corn and soybeans.

Corn supplies held by farmers on March 1 were 57 percent of the total, up from 55 percent a year ago, USDA data show. Total disappearance in the three months ended March 1 rose to 3.47 billion bushels from 3.44 billion a year earlier.

U.S. soybean inventories on March 1 were pegged at 1.334 billion bushels, up from 994 million a year earlier and below the 1.348 billion bushels expected by analysts.

U.S. inventories of all classes of wheat on March 1 rose to 1.124 billion bushels from 1.057 billion a year earlier, the department said. Analysts expected 1.141 billion, on average.