If, as a result of any conservation work projects on state, county, or municipally owned land, the state derives a direct profit from the sale of any such land or the products thereof, the proceeds must be divided equally between this state and the federal government until the federal government has been repaid the amount of its investment in such work, computed at the rate of one dollar per man per day, with a maximum limitation of three dollars per acre [.40 hectare] of land purchased.