Pollution of Illinois agricultural lands by nonfarm activities is only a minor threat to the resource. Mining regulations passed by the Illinois General Assembly in 1962 and by Congress in 1977 sought to improve reclamation so as to make surface mining a temporary use of the land by returning it to productive use. Oil production . Oil brought to the surface brings with it copious amounts of water containing dissolved salts. If allowed to spill, high concentrations of these brine wastes can be toxic to some plants at high.
Regulations now require that such water be disposed of in deep underground rock formations.
Air pollution . The impact on crops of the dry deposition of common pollutants via airborne particles and gases is less studied, as is the impact of more exotic toxic compounds deposited via both dry deposition and precipitation. The long-term effects of global warming, if any, on Illinois agriculture cannot now be predicted. The diverse farm landscape dominant in Illinois until the 1960s contained abundant wildlife. Even now some species thrive, as human manipulation of the land enhances wildlife habitat for certain species.