The board of managers of the experiment station may, whenever it seems necessary, appoint a county agricultural agent for each of the counties of this state, who shall:
a. Be a man of practical experience;b. Reside, during his term of office, in the county for which he is chosen;c. Devote his time to the supervision and furtherance of farm demonstration work in his county, under the supervision and direction of the director of the extension service;d. Receive the salary fixed by the director of the extension service, which salary, or so much thereof as the director of the extension service may require, shall be paid by the county for which the agent is appointed, from money appropriated for that purpose by the county. The board of managers may change the designation of the office of county agricultural agent to such name as it may determine.