The commissioner of agriculture, for the purpose of fostering and developing agriculture within the state of Tennessee, is authorized to pay state aid from the grants made by the general assembly for such purposes to nonprofit agricultural shows held for the purpose of advancing agriculture. Fairs that receive state aid shall use their profits for future fair improvements, increasing their premium lists, and furthering the growth, expansion, and usefulness of fairs in every way possible, and to provide for a possible deficit at some future fair. Whenever a fair converts its profits into the treasury of a county, or pays dividends to stockholders, it forfeits its privilege of sharing in state aid.