Having It Both Ways? Land Use Change in a U.S. Midwestern Agricultural Ecoregion

^*The authors wish to thank Ryan Reker and three anonymous reviewers for their constructive comments on our article that helped make it better. Mr. Auch would like to thank the U.S. Geological Survey's National Land Change Assessment project and Climate and Land Use Change Research and Development program for support of this research.

This article is not subject to U.S. copyright law.

Abstract

Urbanization has been directly linked to decreases in area of agricultural lands and, as such, has been considered a threat to food security. Although the area of land used to produce food has diminished, often overlooked have been changes in agricultural output. The Eastern Corn Belt Plains (ECBP) is an important agricultural region in the U.S. Midwest. It has both gained a significant amount of urban land, primarily from the conversion of agricultural land between 1973 and 2000, and at the same time continued to produce ever-increasing quantities of agricultural products. By 2002, more corn, soybeans, and hogs were produced on a smaller agricultural land base than in 1974. In the last quarter of the twentieth century, ECBP ecoregion society appeared to have “had it both ways”: more urbanization along with increased agricultural output.

城市化被直接连结至农业土地面积的减少, 并因此被认为是对粮食安全的威胁。儘管用来生产粮食的土地面积已然减少, 但粮食产出的变化却经常被忽略。东部玉米种植带 (ECBP) 是美国中西部重要的农业区域。该区域在 1973 年至 2000 年间, 主要透过农地变更, 使得城市土地面积显着成长, 但却也同时不断创造农产品产量的增加。与 1974 年相较之下, 2002 年之际, 有更多的玉米、大豆和食用猪产自于较小型的农业基地。二十世纪的最后二十五年, ECBP 的生态区域社会似乎能够 “两者兼得”: 更多的城市化, 同时伴随着农业产出的增加。

La urbanización ha sido directamente vinculada a la reducción del área de las tierras agrícolas, y en tal condición se la considera como amenaza para la seguridad alimentaria. Aunque el área de tierra utilizada para producir alimentos ha disminuido, lo que con frecuencia se pasa por alto son los cambios ocurridos en la productividad agrícola. Las Planicies del Cinturón Oriental del Maíz son una región agrícola importante del Medio Oeste de los EE.UU. Esta región se ha ganado un espacio significativo de terreno urbana, primariamente con la conversión de tierra agrícola entre 1973 y 2000, a la vez que continuaba produciendo volúmenes cada vez más grandes de productos agrícolas. Para el 2002, más soya, maíz y cerdos fueron producidos sobre una base de tierra agrícola más pequeña que la de 1974. Parece que durante el último cuarto del siglo XX, en la eco-región plana del Cinturón Oriental del Maíz concurrieron las dos cosas: más urbanización simultáneamente con una mayor productividad agrícola.

Key Words::

• Eastern Corn Belt Plains
• increased agricultural output
• urbanization.

关键词::

• 东部玉米种植带
• 增加的农业产出
• 城市化。

Palabras clave::

• Planicies del Cinturón Oriental del Maíz
• aumento de productividad agrícola
• urbanización

Notes

^* The authors wish to thank Ryan Reker and three anonymous reviewers for their constructive comments on our article that helped make it better. Mr. Auch would like to thank the U.S. Geological Survey's National Land Change Assessment project and Climate and Land Use Change Research and Development program for support of this research.

This article is not subject to U.S. copyright law.

¹Data years are as follows: U.S. Census Bureau: Population, housing, and employment data: 1970, 1980, 1990, 2000. U.S. Department of Agriculture: All data were either downloaded or keyed in from http://www.agcensus.usda.gov/. Census dates obtained: 1974, 1978, 1982, 1987, 1992, 1997, 2002. U.S. Geological Survey Land Cover Trends Project: Land use/land cover change data: Nominally 1973, 1980, 1986, 1992, 2000.

²USGS Land Cover Trends project change estimates are given with an uncertainty range using an 85 percent confidence interval.

³USGS Land Cover Trends project definition of “agricultural” LULC is “Land in either a vegetated or an unvegetated state used for the production of food and fiber. This includes cultivated and uncultivated croplands, hay lands, pasture, orchards, vineyards, and confined livestock operations. Note that forest plantations are considered forests regardless of the use of the wood products” (Auch, Drummond et al. 2012, 357).

⁴USGS Land Cover Trends project definition of “developed” LULC is “Areas of intensive use with much of the land covered with structures or anthropogenic impervious surfaces (e.g., high-density residential, commercial, industrial, roads, etc.) or less intensive uses where the land cover matrix includes both vegetation and structures (e.g., low-density residential, recreational facilities, cemeteries, parking lots, utility corridors, etc.), including any land functionally related to urban or built-up environments (e.g., parks, golf courses, etc.)” (Auch, Drummond et al. 2012, 357).

⁵A comparison between sample-based Land Cover Trends ecoregion land cover and “wall-to-wall” land cover for the entire ecoregion was not done because of the following: (1) there are no 1973, 1980, or 1986 “wall-to-wall” land covers available for the ecoregion, and (2) the land cover classifications and methodologies used to produce the land cover data between Land Cover Trends and USGS 1992 and 2001 National Land Cover data sets do not make these directly comparable.

⁶Bushels and tons to tonne conversions are available at http://www.spectrumcommodities.com/pdf/convfactY2K.pdf. Corn = bushels × 0.025400 Wheat and soybeans = bushels × 0.027216Oats = bushels × 0.014515 1 tonne = 1 ton × 0.90718474 1 tonne = 2,204.62 lbs.

⁷There is no known comprehensive county-scale data set of inorganic fertilizer used in the United States, although the USDA (2012b) has multiple data sets devoted to national and state-level analysis (where county-level estimates can be derived). In general, application of nitrogen fertilizer is focused on corn. To calculate an estimated amount of nitrogen applied to corn in the ECBP, we used Census of Agriculture data (from 1974 to 2002) of county-level amounts of corn planted, multiplied those values by state-level values of the percentage of land area treated, and then multiplied that value by state-level values of application rates. These results represent the best estimates possible using available and appropriate USDA data.

Additional information

Notes on contributors

Roger F. Auch

ROGER F. AUCH is a research geographer with the U.S. Geological Survey at the Earth Resources and Observation Science Center (EROS), Sioux Falls, SD 57198. E-mail: [email protected]. Topics of his research are national and regional U.S. land use and land cover change and their associated driving forces.

Chris Laingen

CHRIS LAINGEN is an Assistant Professor in the Geography Program at Eastern Illinois University, 600 Lincoln Avenue, Charleston, IL 61920. E-mail: [email protected]. His primary research interests are regional, rural, and agricultural geography with a specific focus on Corn Belt agriculture and rural land use change.