Like irrigation, government payments diminish the risks associated with farming, although increased costs have raised those risks. It is difficult to make accurate predictions of future trends for land use, population, and agricultural economic return, but analysis of the historical data suggests trends that are likely to continue into the future.
The data used in this article encourage separate analyses of population, agricultural productivity, agricultural income, and environmental outcomes, yet these topics are thoroughly, if imperfectly, intertwined. Historically, population growth has spurred agricultural development, production, and income, and it still does so at national and global levels.
However, in the 21st century at the local level, population growth rarely leads to increases in agricultural input or output, and population decline also has little impact on agriculture. Conversely, agriculture has become so mechanized and efficient, and salaries for agricultural work so low, that growth or stability in agricultural productivity and income can preserve population stability but does not lead to growth.
Metro and suburban dwellers also object to livestock-oriented agricultural activities—often the most profitable of agricultural enterprises—near their homes. On the other hand, changes in the nonmetro population appear to be driven partly by changes in agriculture, which is why populations in the irrigated nonmetro counties have remained larger than those in the dryland nonmetro counties.
There is more farm and nonfarm work where irrigation prevails, and that has helped sustain populations. The connections go beyond the straightforward and economically driven ways that population and agriculture influence each other.
Land-use practices, many of them directly tied to farming, contribute to environmental change. The growth of population in the metro counties has been largely exogenous to the agricultural economy in recent years, but it does have an impact on agriculture. Metro and suburban development takes land from agriculture and water from irrigation. On the other hand, if forecasts of world population growth are correct Tilman et al. Notwithstanding these links between population and agriculture, most of the changes in farming are not caused by changes in population.
Largely external forces have changed farming, including dramatic shifts in weather in the s and prices in the s and, more generally, changes in technology and in the external market forces that affect prices for the inputs farmers use and the products they sell. There is no simple synthesis that links population, agriculture, and environment in the US Great Plains, but the story told here shows the many ways in which these factors have come together and shaped one another since the 19th century.
Even if we initially separate out each factor, any conclusions we draw about prospective outcomes make sense only when they are combined.
Population trends are in some ways the most independent factor in regional change, because the population has been growing rapidly for a long time throughout the United States, mostly in metro regions. The Great Plains region is no exception. Metro population growth in the Great Plains could continue and may accelerate in the future.
On the other hand, the population of the dryland nonmetro counties has stabilized during the last 30 years, while that of the irrigated nonmetro counties has increased slightly, and the proportion of the population over ages 55 and 65 in both dryland and irrigated nonmetro counties has grown rapidly.
While this stability is reassuring, virtually all other US populations are growing. These demographic patterns will bring substantial social change to the plains.
A static, aging population will be even more different from the dominant metro United States in the future than it is now.
All of these trends are likely to continue. Data on agricultural income also show trends that have the potential to persist, and that pose significant challenges for the future. The dominant trend of the last 30 years has been an increase in income from animal production for the non-metro counties. In the metro counties, on the other hand, income from animal production fell sharply and then stabilized in relation to crop production in the past 20 years.
This trend is likely to continue, because growing metro populations have concerns about the air and water pollution produced by intensive animal production Mosier et al.
Income in both metro and nonmetro counties is also at risk, as the ratio of net to gross income has fallen and government payments have increased. The recent increase in the cost of petroleum and natural gas will push the cost of inputs still higher, and the potential that government payments may be reduced will lower incomes.
Plans to develop biofuels from crop residue, and to use corn to produce ethanol and oil seed to produce biodiesel Barrionuevo , have the potential to contribute to a shift in crop selection in the future and will lead to a new period of uncertainty. The irrigated agricultural counties have the greatest short-term potential to respond to a higher demand for corn.
The dryland nonmetro counties also have the potential to gain from the use of plant residues to produce ethanol. At the same time, demand for corn for biofuels will raise prices, which has the potential to affect livestock production.
Higher prices for animal feed, and for fuel to transport the feed to livestock and the livestock to processing plants, can lead to lowered incomes in the livestock sector.
Expanded biofuel production could also lead to adverse environmental impacts such as increased soil erosion and reduced soil carbon. Potential water shortages are another major threat to the future of the Great Plains. Aquifers are declining Kromm and White , Lehe , Wilhite , metro growth is taking water from agriculture, and climate change poses a substantial risk, although its impacts may not all be negative Reilly et al.
Responses to potential water shortages include improvement of dryland cropping systems Peterson et al. Although these changes are likely to be widely implemented, it is unclear whether improved irrigation efficiency, better crop management practices, and reduction in plant transpiration levels associated with increased atmospheric carbon dioxide levels will allow crop yields to be maintained at current levels.
It is likely that these and other improved agricultural techniques will reduce the negative impacts of agriculture on the environment. These techniques, coupled with programs like the Conservation Reserve Program which encourages farmers to convert cropland to grassland , can increase carbon storage and reduce N 2 O soil fluxes and NO 3 leaching. This research draws on the assumption that there are meaningful observations to be drawn from the experience of the Great Plains over the past century, with special consideration of the past 30 or 40 years.
There are fundamental differences in the viability of agriculture and agricultural society in the three areas we have defined, with metro and dryland nonmetro counties more likely than irrigated nonmetro counties to run into problems.
Irrigated nonmetro areas may prove vulnerable because of the increased cost of pumping water from deeper reaches of the aquifer, the increased water demands due to greater evapotranspiration under a warmer climate, and the increased competition with human consumption in metro areas for water resources. At present, however, the conditions in terms of population and production are not as bad as they might be, and not as bad as some observers suggest.
There is little recent evidence to suggest that the near future will be different from the recent past, but the prospect of high energy costs and reduced government payments to farms may disrupt what has been a quarter-century of stability. We see few indications on the horizon that agricultural production will decline sharply, or that patterns of population change will depart radically from those in place since the s and s. The prospect of new trends in petroleum prices, the reduced availability of water for irrigation, and new departures from recent demographic patterns are all cause for continued monitoring.
We thank Susy Lutz and Laurie Richards for assistance with the research and preparation of the manuscript. Summer Fallow in the Western United States. Barrionuevo A. The energy challenge: Boom in ethanol reshapes economy of heartland. New York Times, 25 June. Agroecosystems, nitrogen-use efficiency, and nitrogen management.
Google Scholar. Cunfer GA. On the Great Plains: Agriculture and Environment. Simulated effects of dryland cropping intensification on soil organic matter and greenhouse gas exchanges using the DAYCENT ecosystem model. Environmental Pollution. Journal of Environmental Quality. Nitrogen fertilizers: Meeting contemporary challenges. Gutmann MP. ICPSR version. German-origin settlement and agricultural land use in the twentieth century Great Plains.
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Hargreaves MWM. Lawrence University Press of Kansas. Hewes L. Lincoln University of Nebraska Press. Nitrogen use in the United States from — and potential future trends. Agricultural dependence and changing population in the Great Plains. Population Change and Rural Society. Dordrecht The Netherlands Springer.
Variability in adjustment preferences to ground-water depletion in the American High Plains. Water Resources Bulletin. Lehe JE. The effects of depletion of the Ogallala aquifer and accompanying impact on economic and agricultural production in the southern high plains region of the United States. In the drier, western parts of the Northern Plains, most crops are grown under dryland conditions e. Furthermore, transfer of water from agricultural to urban use in metropolitan areas e. Cutforth, H.
McGinn, K. McPhee, and P. Adaptation of pulse crops to the changing climate of the Northern Great Plains. Large farms and cattle ranches cover much of the Great Plains. In fact, it is some of the best farmland in the world. Wheat is an important crop, because wheat can grow well even without much rainfall. Large areas of the Great Plains, like this land in Texas, are also used for grazing cattle. Winds that blow across the Great Plains are now being used to turn the blades of electricity generating windmills.
Extreme temperatures — freezing cold winters and boiling hot summers meant crops would freeze in winter and shrivel in the summer. Hailstorms and thunderstorms also destroyed crops. Hot summers could cause Prairie Fires that destroyed crops, livestock and people. Ploughing the land — the Great Plains had never been farmed before, so ploughing the land was backbreaking work.
Disease — It was difficult to keep the earth-built houses clean. This meant lots of pests such as mice, snakes and bed bugs were able to spread disease. Grasshoppers — some years huge plagues of grasshoppers would sweep across the Plains, destroying everything in their path and polluting water sources.
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