The Alexandria City Council has agreed to lease the Alexandria Dukes baseball team a city-owned field at Cora Kelly Elementary School, but has left in doubt the team's future in the city beyond the current season.

At its meeting last week, the council unanimously agreed to renew its lease with the Class A minor league team, which uses the renovated field in the Arlandria section of the city, as its home base. Estimated rent to the city, based on a formula involving attendance, is expected to be $1,000.

But the council -- which is now wrestling with the 1980-81 budget -- turned down pleas from team officials that the council participate in the construction of a new field in the Cameron Run area of the city.

Team President A. Eugene Thomas, a local builder, proposed that he and four unnamed associates buy a $500,000 tax-free bond from the city at 8 percent, which the city would repurchase in 10 years. Under such an arrangement, the $40,000 interest the purchasers would receive annually would not be taxed, Thomas later explained.

"Forget it," said Mayor Robert L. Calhoun, adding that the council would have a hard time explaining to citizens why it sanctioned a baseball park for a private club when it was trimming some municipal services.

In another action, the council defeated 6 to 0 with one abstention, a request by a developer and a local politician to convert 17 aging apartments to condominiums. The vote, during which council member Carlyle C. Ring Jr. (R) abstained, means that developer Charles T. Akre Jr. and his business partner Del. David G. Speck (R-Alex.) will not be able to convert the units which they are purchasing in a building at Russell Road and King Street.

The conversion project had been opposed by a local civic association, which said it feared it could set a precedent for the conversion of other buildings in the neighborhood.

The council voted to study land use planning in the area.