(Repeats to clarify gasoline in headline. No changes to text)
* Mississippi River crests at near-record 48 ft in Memphis
* Floods wash out 3 mln acres cropland, hits rice hard
* Gasoline prices jump on fears refiners in path
By Karl Plume and John Branston
CHICAGO/MEMPHIS, Tenn., May 10 (Reuters) - Rising floodwaters on the Mississippi River have displaced thousands of residents and flooded 3 million acres of farmland as it surges past Memphis to the U.S. Gulf Coast, where it threatens to disrupt 10 oil refineries in Louisiana.
Gasoline prices RBc1 jumped by more than 2 percent in New York on Tuesday as traders speculated that the massive flooding from heavy spring rains and snow melt could disrupt refineries on southern stretches of the Mississippi in the next two weeks.
The refineries threatened by the flooding account for 14 percent of U.S. refined gasoline capacity. Pump prices in the United States already have topped $4 a gallon in many states, stretching consumer budgets.
The floods threatened to postpone or cancel planting of rice on 300,000 acres in Arkansas, amounting to 10 percent of the total rice acreage in the United States, the world's third-largest exporter of the grain.
While only about 1 percent of agricultural land planted with major crops in the United States has been affected, the loss comes on top of dwindling U.S. grain stockpiles, weather woes in other agricultural exporting nations and rising demand, all of which have sent grain prices up steeply.
The United States' largest river system, a transportation artery that cuts 2,320 miles (3,734 km) through America's heartland to the Gulf of Mexico, crested at 47.87 feet (14.6 meters) in Memphis on Tuesday, the National Weather Service said.
The historic downtown of the country and blues music capital was spared from major damage as the wall of water headed southward toward the Gulf of Mexico.
The U.S. government prepared to open a second spillway in Louisiana to divert waters and ease flows at New Orleans and Baton Rouge. The action will interrupt crude oil shipments to one small refinery.
"They don't call it the Mighty Mississippi for nothing," said Steve Shular, spokesman for the Shelby County Office of Preparedness in Tennessee.
Barge traffic is moving along the river although some restrictions have been applied to some sections based on size, speed and motor power of barges, the U.S. Coast Guard said Tuesday. The Mississippi is a major shipping route to the port of New Orleans.