The Army has abandoned a commitment to turn over 135 acres of unused land at Fort Belvoir for use as a park in southern Fairfax County, county supervisors said Monday.

Local leaders said the transfer of the land would help fix a 600-acre deficit of park space in Fairfax, a need made more critical by the roughly 19,000 jobs slated to move to Belvoir by 2011 under orders of the Base Realignment and Closure Commission.