The Martha’s Vineyard Land Bank has joined forces with the Island Affordable Housing Trust to buy 22.5 acres off State Road in West Tisbury for the combined purpose of conservation and affordable housing.

The property, which is near the intersection of Old County Road on the south side of State Road, was formerly owned by the late Eleanor Bennett. The seller is Molly Belle Bennett, Mrs. Bennett’s daughter and the executor of her estate.

The total sale price is $2.2 million. The land bank paid $1.86 million for 14.5 acres which it will own outright, and also will place a conservation restriction on four additional acres that will be owned by the affordable housing trust. The trust paid $350,000 for eight acres and plans to build a maximum of eight units of affordable housing on four of the eight acres.

The Bennett family will retain a three-acre lot.

The land bank first approached the Bennett family about a possible purchase in 1987. Eleanor Bennett died in 2005.

The property lies across the road from the John Presbury Norton Farm, also owned by the land bank. Land bank executive director James Lengyel said yesterday that the principal benefit of the land is to keep that stretch of State Road free from development, as well as protecting an ancient way. Old Holmes Hole Road runs along the entire eastern boundary of the land.

“The land bank wanted to preserve as much as possible of that ancient way corridor,” Mr. Lengyel said. He said the property is also marked by excellent agricultural soils.

To date the land bank has collaborated on 12 different affordable housing ventures on the Vineyard, beginning with Sepiessa Point in West Tisbury in 1991.

“The land bank continues to find properties where affordable housing and conservation work harmoniously. Sometimes the land accommodates the two uses and sometimes it doesn’t. In this case it did,” Mr. Lengyel said.