For general property tax purposes, the value of land, not less than 5 acres in area, which is actively devoted to agricultural or horticultural use and which has been so devoted for at least the 2 successive years immediately preceding the tax year in issue, shall, on application of the owner, and approval thereof as hereinafter provided, be that value which such land has for agricultural or horticultural use.
N.J.S. § 54:4-23.2