This district is intended to provide an area primarily for agricultural uses or the extraction of the various products such as oil, minerals, rock and gravel from the earth. The rural nature and low density of population in this district requires only that the buildings and extraction facilities related to the uses of this district have a reasonable setback from streets and highways. It is the purpose of this district to protect such uses from unplanned urbanization so long as the land therein is devoted primarily to agriculture or extraction of minerals. (Prior code § 16-9)