Harford County's revenue would grow by an estimated $4 million a year as a result of a 1 percent county real estate transfer tax the County Council will consider.
During its final week, the General Assembly gave the county the authority to enact the tax.
The measure must be signed by the governor and adopted by the County Council before taking effect.
Half of the revenue would be used to purchase farmland development rights, and the other half to finance the acquisition and construction of school sites, County Executive Eileen M. Rehrmann said.
A change in the county charter is needed to use the money for agricultural land preservation, and such changes require a public referendum. The County Council is expected to place the amendment on the ballot for a vote in November.