Supporters of a proposal to liberalize marijuana laws in the District of Columbia have called off their drive to put the controversial question on the Nov. 4 ballot, after failing to collect the required number of signatures.

George L. Farnham, chairman of the Committee for the D.C. Marijuana Initiative said yesterday that his group had collected only 10,000 of the necessary 12,451 signatures as of Monday. Since the group had hoped to present at least 16,000 signatures to the Board of Elections and Ethics by the July 7 deadline, Farnham said, the committee decided not to press its campaign into the Fourth of July weekend.

"We felt we could have gotten more [signatures] at the concert on the Mall on the Fourth but we thought we might have a problem with having signatures from out-of-towners. So we decided to cut our losses and reorganize ourselves for the next electio in September 1981," said Farnham.

The measure would have abolished all criminal penalties for the possession of small amounts of marijuana, and would have allowed adult users to grow small quantities in their homes. Possession of the drug now is a misdemeanor in the District, punishable by up to one year in jail or a $1,000 fine or both.

Farham estimates that the committee spent about $20,000 on the campaign and is now $5,000 in debt. Farnham said he was the largest single contributor, donating $2,000 of his own money.

The Rev. Andrew Fowler, pastor of Capital View Baptist Church and executive secretary of the Committee of 100, a ministers group that opposed the measure, said he was not surprised to hear of the marijuana supporters' setback. He said his committee now will focus on the new drive to legalize gambling in the District, whose supporetrs also are seeking signatures.