The director of the agency that is to distribute humanitarian aid to the Nicaraguan Contras said Friday some are so desperate for food they are eating tree roots.

Alan Woods of the Agency for International Development told a Senate Foreign relations subcommittee that he is planning to start sending a total of about $450,000 a month to Contras based in Nicaragua so they can buy food.Woods said a stalemate in negotiations between the Contras and the Sandinista government on allowing shipments of food to guerrillas inside Nicaragua has forced him to plan to send cordobas, the Nicaraguan monetary unit, to the fighters.

"We have reports of people eating tree roots as they struggle through the jungle to get to where the food is" at camps along the Honduran border, Woods said.

"These people desperately need food."

Woods said the cash would amount to about $1 per day per fighter. He said conditions in the area do not allow a conventional accounting, but that the agency will soon know if the money is not being delivered by couriers overseen by Nicaraguan Contra commanders.

"Soldiers, deprived of $1 a day for food, will make it known quickly if they are not getting food," Woods said. "That is the best we can do."

The agency has the responsibility for distributing $17.7 million in humanitarian aid to the guerrillas that have fought without significant success since 1981 to topple the Soviet-armed and Cuban-trained Nicaraguan government.

Congress in February cut off military aid to the Contras, who President Reagan says were fighting communist subversion. The guerrillas negotiated a tentative truce with the Marxist-led government in the border town of Sapoa, Nicaragua, March 23. The humanitarian aid is intended to keep the Contras together while they seek a permanent political settlement.

Woods said many fighters are walking out of Nicaragua because the talks between the government and the Contras have failed to set up an arrangement for the agency to supply food, clothing, and medicine to camps.

The administration has accused the Sandinistas of intentionally obstructing the talks with the goal of forcing the Contras to flee to camps in Honduras where American-supplied food is available.

Sen. Christopher Dodd, D-Conn., chairman of the subcommittee on the Western Hemisphere, said the system will lack proper accounting and that the agency should seek a role for an independent organization, such as the International Red Cross, to deliver the supplies.

The Contras previously rejected a role for the International Red Cross, saying it would be bad for troop morale to receive supplies from an agency that typically aids refugees and victims of disasters.

Woods said the Contras and the Sandinistas cannot agree on a neutral group to deliver the assistance.

"Let me emphasize that we have taken this particular step as a last resort," he said. "Until the Nicaraguan government agrees to allow routine delivery of food, as called for in the Sapoa agreement and expected by Congress, we must use other means of getting aid to the resistance inside Nicaragua."