The farmer who drove his tractor into a pond near the National Mall and threatened to set off explosives surrendered Wednesday after a 48-hour standoff that snarled rush-hour commutes and kept some monuments off limits to tourists.

Dwight Watson, who was protesting farm policies he said were forcing him out of his family's tobacco-farming business, was taken into custody at about midday. No explosives or weapons were found in a preliminary search of both the tractor and the Jeep he had abandoned in the large pond in Constitution Gardens, a federal park east of the Vietnam Veterans Memorial.

U.S. Park Police planned to consult with federal prosecutors on potential charges against the 50-year-old Watson of Whitakers, N.C. Authorities may decide to seek a psychiatric exam.

"He was very calm and very willing to go along with the program and followed the steps that he had outlined and the negotiator had outlined to a tee," said Teresa Chambers, the Park Police chief.

Details of the surrender were settled during telephone conversations Tuesday and early Wednesday.

Watson had a legal permit to demonstrate with his tractor near the Washington Monument from last Sunday to this Saturday. But at about noon Monday, he drove his Jeep and a trailer carrying the tractor into the water.

He told authorities he would detonate explosives if anyone tried to forcibly remove him.

Chambers said a lack of sleep may have contributed to his willingness to give up. Police kept him awake with bright lights and noise Tuesday night.

Authorities stood by their decision to close a portion of the National Mall and shut a major commuter route between downtown Washington and its Virginia suburbs, causing rush-hour gridlock.

Washington residents -- already jittery about the prospect of war, the possibility of retaliatory attacks and memories of jammed streets from the Sept. 11 attack on the Pentagon in Virginia -- wondered throughout the standoff how one farmer could create so much chaos.

Tourists asked police and reporters how to reach the Lincoln Memorial without using a pedestrian walkway blocked by police crime scene tape.

Watson, whose family has run a farm for several generations, said cuts in government subsidies to tobacco farmers have made it difficult for American growers to compete internationally. Last weekend, he decided he could no longer afford to farm.