The corn market, along with most other commodity and financial markets, was negatively affected by the uncertainty created by the natural disaster in Japan and ongoing conflicts in North Africa and the Middle East.

The Japanese situation is especially important for corn because Japan is the largest importer of U.S. corn, said a University of Illinois economist.

"Japan accounted for 33 percent of U.S. corn exports in 2008-09 and 30 percent in 2009-10, typically importing about as much U.S. corn as the next two largest importers, Mexico and South Korea, combined," said Darrel Good.

The damage from the recent earthquake and tsunami has the potential to reduce Japanese feed demand and import capabilities in the short-run. Most experts believe that long-term disruptions will be minimal and that Japan will continue to import large quantities of U.S. corn.

New export sales of U.S. corn were large in six of the seven weeks ended March 10, averaging 41.6 million bushels per week. Adjusting for Census Bureau export estimates through January, corn export sales now need to average only 21 million bushels per week to be on track for reaching the USDA export projection for the year.

In its daily reporting of large sales, the USDA reported sales of nearly 18 million bushels of corn to South Korea last week. In addition, there was speculation that a sale of 4.5 million bushels of U.S. corn to unknown destinations was actually a sale to China. Similar rumors circulated earlier in the year.

"Corn export prospects got another boost from the first official Argentine forecast of this year's harvest. That forecast was 59 million bushels less than the most recent USDA forecast," Good said.

Although corn export sales have been large in recent weeks, weekly export inspections have mostly been smaller than the rate required to reach the USDA export projection for the year. Adjusting for Census Bureau export estimates, it appears that corn export inspections need to average 42.2 million bushels per week during the last 24 weeks of the marketing year in order to reach 1.95 billion bushels. To date, exports have averaged only 33.3 million bushels per week. For the most recent five-week period, the average was 35.7 million bushels, he added.

According to Good, prospects for domestic feed demand for corn got another boost from USDA's March Cattle on Feed report. That report indicated that March 1 inventories in feedlots with a capacity of 1,000 head or more were 5 percent larger than inventories of a year ago. That continues the pattern of January and February.