The National Resources Inventory (NRI) is a statistical survey of natural resource conditions and trends on non-Federal land in the United States. Non-Federal land includes privately owned lands, tribal and trust lands, and lands controlled by state and local governments.
The NRI provides nationally consistent statistical data on the development of non-Federal rural lands for the period 1982–2007. To assess conservation issues this information on development must be analyzed in conjunction with other NRI data elements.
The net change of rural land into developed land has averaged 1.6 million acres per year over the last 25 years, resulting in reduced agricultural land, rangeland, and forest land. Loss of prime farmland, which may consist of agriculture land or forest land, is of particular concern due to its potential effect on crop production and wildlife.
Development of Non-Federal Rural Land — Nationally
Between 1982 and 2007, 41 million acres were newly developed for urban or transportation uses. By 2007, the total developed area in the contiguous United States was 111 million acres—an increase of 56% from 71 million acres in 1982. (Table 12 and Table 13)
Almost three-fourths of the developed land is classified as large urban and built-up areas of 10 acres or more. Land in this category increased by 82% from 1982 to 2007—from 45 million acres to 82 million acres. (Table 12)
Rural transportation land (roads, railroads, and associated rights of way) increased from 21 million acres in 1982 to 22 million acres in 2007—a 4% increase. (Table 12)
Small built-up areas of less than 10 acres, the smallest category of developed land, increased 55% from 1982 to 2007. (Table 12)
Over the same period 1 million acres also reverted back to rural land. (Table 6)
The rate of development was slightly over 1.3 million acres per year during the period 1982–1992, spiked at over 2 million acres annually during the period 1992–2002, and declined to 1.5 million acres annually from 2002 to 2007.
Of the newly developed land during the 1982–2007 period, 41% was non-Federal forest land, 27% was cropland, 17% was pastureland, and 13% was rangeland. (Table 13)
The share of newly developed land from forest land and pastureland remained steady over the period 1982–2007. The share that came from cropland declined from 29% during 1982–1987 to 21% during 1997–2002 and to 22% during 2002–2007. The share that came from rangeland declined from 13% during 1982–1987 to 10% during 1992–1997, then jumped to 15% during the period 1997–2002. (Table 13)
Development of Non-Federal Rural Land — Regionally
Between 1982 and 2007, more land was developed in the Southeast Farm Production Region than in any other. New development over this period amounted to 8% of the non-Federal rural land in that region. (Table 31)
Less new development occurred in the Northern Plains than in any other region during the 1982–2007 period: about 806,200 acres, less than 1% of the non-Federal land. (Table 31)
In every region but the Southern Plains and Mountain States, the peak years for development occurred from 1992 to 1997. In those two regions, development peaked during the period 1997–2002. (Table 31)
Following is the regional breakdown of new development (1982–2007) expressed as a percentage of all non-Federal land that had not been developed as of 1982:
New Development between 1982 and 2007 by Farm Production Region,
in Millions of Acres, with Margins of Error
Farm Production Region
New Development, 1982-2007
Undeveloped Non-Federal Land in 1982
New Development as a Percentage of Undeveloped Non-Federal Land in 1982
Development of Prime Farmland
Prime farmland is land that has the best combination of physical and chemical characteristics for producing food, feed, forage, fiber, and oilseed crops, and is also available for these uses (the land could be cropland, pastureland, rangeland, forest land, other rural land, or CRP land, but not urban built-up land or water). It has the soil quality, growing season, and moisture supply needed to economically produce sustained high yields of crops when treated and managed, including water management, according to acceptable farming methods. In general, prime farmlands have an adequate and dependable water supply from precipitation or irrigation, a favorable temperature and growing season, acceptable acidity or alkalinity, acceptable salt and sodium content, and few or no rocks. They are permeable to water and air. Prime farmlands are not excessively erodible or saturated with water for a long period of time, and they either do not flood frequently or are protected from flooding.
There were 326 million acres of prime farmland in the 48 contiguous states in 2007. Of this, 202 million acres (62%) were cropland; 50 million acres (15%), forest land; 37 million acres (12%), pastureland; and 20 million acres (6%), rangeland. (Table 15)
About 14 million acres of prime farmland were lost to development during the 1982–2007 period— over 500,000 acres annually. (Table 17)
Development of prime farmland accounted for approximately 33% of all development of rural land during the 1982–2007 period. This loss amounts to about 4% of all prime farmland. (Table 13, Table 15, and Table 17)
All Farm Production Regions experienced net losses in prime farmland during the 1982–2007 period—the greatest loss being over 2 million acres in the Corn Belt. Six other regions lost over 1 million acres: Appalachian, Southern Plains, Southeast, Northeast, Delta States, and Lake States. (Table 33 and Table 34)
On a percentage basis the greatest losses occurred in the Mountain and Northeast Farm Production Regions, each of which lost more than 10% of their prime farmland between 1982 and 2007. (Table 33)