Subject to the provisions of this subtitle, the Administration shall establish a voluntary land acquisition program under which it shall purchase residentially occupied real property subject to a cumulative noise exposure of 70 LDN or greater, as identified by the most recently adopted airport noise zone, if the owner of the real property volunteers to sell the real property to the Administration. Local governments are encouraged, in the exercise of their police powers, to cooperate with Administration efforts to create a land use buffer zone composed of noise compatible commercial, industrial, and other nonresidential uses in areas contiguous to the airport. The Secretary is directed to request full funding for the program as part of the 1989 fiscal year budget and subsequent departmental budget requests.