Parton, W.J., Myron Gutmann, and D. Ojima. 2007. "Long-term trends in population, farm income, and crop production in the great plains." Bioscience, 57(9): 737-747.
Despite concern about the social, economic, and ecological viability of the agricultural Great Plains, a century-long examination reveals that threats to society, economy, and environment are counterbalanced by surprising stability and the potential for short- and medium-term sustainability. Populations in metropolitan counties have grown, whereas rural populations may now be stable; both metropolitan and rural populations are aging. Technological advances in the past five decades enhanced production in the Great Plains despite periodic adverse economic and environmental conditions, and increases in crop yields, animal feeding, and government payments have sustained agriculture and income. Nonmetropolitan counties with irrigated farming have been more successful than those without irrigation. However, overuse of groundwater and rising energy costs for irrigation affect economic margins and the ability to sustain environmental integrity. Long-term projections of agricultural productivity must balance recent stability with the risks posed by reduced irrigation, higher energy prices, disruptive demographic changes, and further loss of environmental integrity.