It is hereby declared to be the policy of the legislature to integrate the conservation of soil and water resources into the production of agricultural commodities to insure the long-term protection of the soil and water resources of the state of Iowa, and to encourage the development of farm management and agricultural practices that are consistent with the capability of the land to sustain agriculture, and thereby to preserve natural resources, control floods, prevent impairment of dams and reservoirs, assist and maintain the navigability of rivers and harbors, preserve wildlife, protect the tax base, protect public lands and promote the health, safety and public welfare of the people of this state.