The county board, after receiving the reports of the county committee and other comments, and after such public hearing, may adopt as a plan the proposal or any modification of the proposal it deems appropriate, including the inclusion, to the extent feasible, of adjacent viable farmlands, and the exclusion, to the extent feasible, of non-viable farmland and non-farm land. The county board shall act to adopt or reject the proposal, or any modification of it not later than 45 days from the date the county committee’s recommendation on the proposal was submitted to it. The county board shall notify the Department of Agriculture of the adoption or rejection of the proposal and shall provide the Department with a description of the agricultural area within 45 days of taking such action.