Furthermore, minimum lot size restrictions in Indiana primarily address the public health concerns of on-site waste disposal systems, not farmland preservation. Fortunately, unconventional zoning methods do exist to preserve prime agricultural land. Open space zoning and exclusive agricultural zoning are two of the most promising. The conventional approach to development results in an entire development parcel being covered with houselots and subdivision streets. Open space zoning, on the other hand, relies on the principal of cluster development, whereby new homes are clustered onto part of the development parcel.
Clustering allows the remainder to be preserved as productive farmland or unbuilt open space.
Since only the density and not the number of houses is changed, open space zoning can permanently protect a substantial portion of every development tract's agricultural productivity without decreasing the development potential for both landowner and developer. Exclusive agricultural zoning is less frequently used than nonexclusive zoning such as open space zoning, because it prohibits nonagricultural use of the land within the district. The main advantage is that it ensures there will be no conflict between residential and agricultural uses. A more landowner friendly form of exclusive agricultural zoning is the voluntary creation of agricultural districts. The benefits which farmers obtain by voluntarily joining an agricultural district may include differential assessment, protection against nuisance ordinances, and limits on public investments for nonfarm improvements.