A D.C. Superior Court jury has acquitted a Kansas farmer of charges that he assaulted a police officer with his tractor last February during a farmers protest here.

The jury deliberated for an hour last Thursday before finding Patrick Ryan, of Gem, Kans., innocent of a charge that he drove his tractor into D.C. police officer William Clark on Feb. 25.

Assistant U.S. Attorney John R. Fisher contended in the three-day trial before Judge Leonard Braman that Ryan intentionally allowed his tractor to "lurch forward" and strike Clark while Clark and several other officers were trying to arrest Ryan. Clark was not injured, according to testimony.

E. William Thompson, Ryan's attorney, told the jury in his closing argument that the government had presented "trumpted-up charges" against his client. He said that police "acted like Keystone Koppers" in their efforts to drag Ryan from the cab of his tractor and arrest him.

Braman cited Thompson for contempt of court twice during the proceedings. The first citation occurred when Thompson broke an agreement with the judge not to question his client about the reasons for coming to Washington, and again when Thompson said that the government's indictment of Ryan should have reflected that Ryan was assulted by police.