The Reagan administration yesterday announced a five-year, $200 million plan to improve food production in Morocco, saying at the same time that a military facilities agreement with that country should be completed next week.

The State Department announcement came shortly after King Hassan II left Washington after three days of discussions with President Reagan and other senior U.S. officials. Hassan is expected to return home next week.

The new aid plan, described as "a cooperative venture in dry-land agricultural development," requires Moroccan contributions in addition to the $200 million that the United States "hopes to be able to provide" over the next five years.

Officials said the program is likely to center on production of hard wheat in central Morocco.

The proposed program would represent a large increase over the currently requested development aid plan of $13.5 million for Morocco.

The military agreement, which would permit U.S. use of at least one Moroccan air base in emergency situations, has been under discussion since Secretary of State Alexander M. Haig Jr. visited Marrakech in February.

After an on-again, off-again series of signals during Hassan's visit, the U.S. statement yesterday said "we expect agreement on a text" of a detailed facilities agreement before the king leaves.

The statement described the planned agreement as one providing U.S. access to Moroccan military facilities "in special contingencies of concern to both countries."

This skirted the issue of whether the access is primarily for U.S. or Moroccan benefit, as well as the ticklish issue of Moroccan advance approval.

In White House briefings for reporters, U.S. officials said advance approval will be obtained before American military forces use the Moroccan facilities. They refused comment on reports that Morocco, an Islamic country with close ties to the Arab world, had insisted that its facilities could not be used in any military action against Arab states.

Discussions were held during Hassan's stay on shipments of U.S. arms, including M60 tanks and Maverick missiles, according to Pentagon officials. No conclusions about the military supply were announced.

Some U.S. military construction is anticipated at the Moroccan base, still unnamed, that is the subject of the emergency use agreement. This construction, officials suggested, is likely to include improvement of runways and storage facilities.