It was quite a gift: 285 acres of rolling farmland, soybean and tobacco fields, a stream, several houses and a $600,000 endowment to keep it all going. Last week, the Clagett estate outside Upper Marlboro officially was handed over to the Chesapeake Bay Foundation, an Annapolis-based conservation and educational organization.

Charles Clagett, a wealthy Baltimore lawyer who died in 1972, wanted his property to be used for a school. But the trustees found the estate did not have enough money to start a school and keep it going. They decided to give the land to the foundation because one of its main purposes is to teach students about Chesapeake Bay.

The foundation already has a total of 1,400 acres in the Chesapeake Bay area, but Acting Director William C. Baker said "We've never had the opportunity to have a piece of land that is upland. There's a lot of interesting things we can do, curriculum-wise, with it."

Baker said the 10 members of the foundation's fulltime teaching staff are now devising a curriculum using the Clagett property.

"They will work on that over this winter," he said. "We hope initially to have limited programs this spring, and a full-blown education center might develop in a year or so."

The foundation has education centers on Smith and Fox islands on the bay itself, in Baltimore, and on Meredith Creek near Annapolis. This year, about 13,000 students have taken part in study programs lasting from one day to two weeks, Baker said. About half were public school pupils sponsored by the Maryland Department of Education.

Baker said the Clagett property will give students the chance to study the bay from a new angle.

"This is one of the more important parts of the watershed, and having the Clagett farm will enable us to take tests and samplings of the complete spectrum," he said.

Water from the Back Branch River, which runs through the property, flows north under Ritchie Marlboro Road and Brown Station Road to join the Western Branch River. This flows southeast past the Duke of Marlboro Country Club, skirts Upper Marlboro and then heads south to join the Patuxent near Mount Calvert on the Anne Arundel County line. Fifty miles farther south, the river empties into Chesapeake Bay.

Baker said students on two-week programs can follow this progression, taking samples of water along the way to monitor and study the changes it undergoes.

"Also, we hope to develop studies of what sort of sediments are running off the land and how they affect the water, and how the soil stays on the land," he added.

Baker said the foundation hopes to keep the farms intact for the most part; the three tenant farmers now working the Clagett land are expected to remain.

"The only changes we may make are in innovative forms of agriculture," he said. For example, he said, there may be experiments in "minimum-till" and "no-till" farming, in which the land is ploughed as little as possible to keep topsoil from washing away with the rain. Baker said he hopes these experiments will be conducted with the help of the University of Maryland.

William C. Addison Jr., a nephew of Charles Clagett who has farmed land on the Clagett property for nearly seven years, said he was a "little apprehensive" about the foundation's plans, but agreed "it could work out very nicely."

"I've been involved in a lot of the things they are interested in," he said. "I'll kind of have to wait and see."

The Chesapeake Bay Foundation, started in 1965, now has about 10,000 members. It has 25 fulltime staff members working in education, legal protection and conservation.