Agricultural zoning is generally used by communities that are concerned about maintaining the economic viability of their agricultural industry. Agricultural zoning typically limits the density of development and restricts non-farm uses of the land. In many agricultural zoning ordinances, the density is controlled by setting a large minimum lot size for a residential structure. Densities may vary depending upon the type of agricultural operation. Agricultural zoning can protect farming communities from becoming fragmented by residential development. In many states, agricultural zoning is necessary for federal voluntary incentive programs, subsidy programs and programs that provide for additional tax abatements.