U.S. corn stockpiles have hit an eight-year low, dropping 7.9 percent on March 1 from 2011 numbers, according to U.S. Department of Agriculture data.

Inventories fell to 6.009 billion bushels, down from 2011's 6.523 billion bushels and the lowest for that time period since 2004. "It’s going to be a tight supply situation until farmers begin harvesting this year’s crops,” said Marty Foreman, an economist for Doane Advisory Services Co. “We still need to grow a good crop this year to rebuild inventories.” Corn futures for May delivery fell 2.6 percent to $6.04 per bushel on March 29 on the Chicago Board of Trade, after reaching a two-month low of $6.03. “The biggest price factor for corn over the next month to six weeks will be planting progress and how much rain falls in parts of the Midwest where soil moisture has been depleted,” said Foreman.

Wheat supplies have also fallen, by 16 percent to 1.201 billion bushels from 1.424 billion bushels in 2011. May futures dropped 2.9 percent on March 29 to $6.125 per bushel.