Total Surface Area, by Land Cover/Use
In thousands of acres, with margins of error
Land Cover/Use |
1982 |
1987 |
1992 |
1997 |
2002 |
2007 |
2012 |
2017 |
Federal land |
312.2
-- |
309.5
-- |
334.0
-- |
334.1
-- |
341.9
-- |
347.4
-- |
369.9
-- |
370.3
-- |
Water areas |
393.0
-- |
397.6
-- |
401.8
-- |
401.9
-- |
412.9
-- |
420.6
-- |
424.9
-- |
426.9
-- |
Non-Federal Land |
Developed |
2,849.3
± 116.9 |
3,052.9
± 122.0 |
3,320.5
± 133.1 |
3,688.9
± 147.0 |
3,910.7
± 140.4 |
4,084.0
± 144.4 |
4,164.2
± 147.6 |
4,224.5
± 146.5 |
Rural |
22,890.3
± 119.3 |
22,684.8
± 125.1 |
22,388.5
± 136.3 |
22,019.9
± 150.4 |
21,779.3
± 144.1 |
21,592.8
± 148.7 |
21,485.8
± 152.0 |
21,423.1
± 151.1 |
Total |
25,739.6
± 12.4 |
25,737.7
± 12.2 |
25,709.0
± 12.5 |
25,708.8
± 13.2 |
25,690.0
± 13.8 |
25,676.8
± 15.0 |
25,650.0
± 15.2 |
25,647.6
± 15.7 |
Total surface area |
26,444.8
-- |
26,444.8
-- |
26,444.8
-- |
26,444.8
-- |
26,444.8
-- |
26,444.8
-- |
26,444.8
-- |
26,444.8
-- |
|
|
Non-Federal Rural Land, by Land Cover/Use
In thousands of acres, with margins of error
Land Cover/Use |
1982 |
1987 |
1992 |
1997 |
2002 |
2007 |
2012 |
2017 |
Cropland |
12,383.7
± 173.2 |
12,271.7
± 183.0 |
11,866.6
± 167.0 |
11,605.8
± 206.0 |
11,314.3
± 208.3 |
11,121.4
± 225.5 |
11,119.3
± 229.4 |
11,231.1
± 224.4 |
CRP Land |
--
|
55.1
-- |
314.1
-- |
323.3
-- |
194.1
-- |
180.0
-- |
137.4
-- |
67.2
-- |
Pastureland |
2,774.3
± 132.7 |
2,471.1
± 124.9 |
2,329.8
± 126.4 |
2,060.3
± 145.9 |
2,244.1
± 147.2 |
2,249.9
± 160.0 |
2,185.7
± 160.6 |
2,045.8
± 156.6 |
Rangeland |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
Forest Land |
6,727.2
± 180.8 |
6,950.9
± 204.8 |
6,974.4
± 222.2 |
7,078.2
± 206.2 |
7,167.7
± 211.9 |
7,130.8
± 202.0 |
7,135.3
± 203.7 |
7,145.3
± 202.6 |
Other Rural Land |
1,005.1
± 66.7 |
936.0
± 70.1 |
903.6
± 59.9 |
952.3
± 61.2 |
859.1
± 79.1 |
910.7
± 87.9 |
908.1
± 96.0 |
933.7
± 96.3 |
Total Non-Federal Rural Land |
22,890.3
± 119.3 |
22,684.8
± 125.1 |
22,388.5
± 136.3 |
22,019.9
± 150.4 |
21,779.3
± 144.1 |
21,592.8
± 148.7 |
21,485.8
± 152.0 |
21,423.1
± 151.1 |
|
|
Prime Farmland, by Land Cover/Use
In thousands of acres, with margins of error
Land Cover/Use |
1982 |
1987 |
1992 |
1997 |
2002 |
2007 |
2012 |
2017 |
Cropland |
9,669.9
± 144.8 |
9,597.2
± 144.9 |
9,299.9
± 140.4 |
9,097.5
± 165.9 |
8,885.5
± 219.6 |
8,768.9
± 220.6 |
8,769.8
± 221.8 |
8,798.9
± 225.0 |
CRP Land |
--
|
39.7
± 10.0 |
241.1
± 32.5 |
256.0
± 26.4 |
155.9
± 34.6 |
130.7
± 23.7 |
95.1
± 32.1 |
42.6
± 8.1 |
Pastureland |
758.5
± 89.8 |
648.8
± 88.4 |
621.7
± 77.0 |
574.7
± 68.5 |
733.0
± 73.2 |
733.7
± 74.3 |
713.9
± 83.6 |
676.1
± 72.5 |
Rangeland |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
0.0
-- |
Forest Land |
1,255.3
± 83.5 |
1,304.7
± 84.6 |
1,291.5
± 86.3 |
1,292.4
± 85.6 |
1,323.0
± 127.5 |
1,313.7
± 123.5 |
1,297.4
± 123.4 |
1,300.4
± 127.1 |
Other Rural Land |
308.8
± 50.4 |
275.3
± 42.2 |
261.1
± 41.5 |
279.6
± 47.6 |
259.2
± 46.9 |
291.9
± 58.5 |
292.1
± 59.7 |
309.9
± 56.3 |
Total Prime Farmland |
11,992.5
± 191.2 |
11,865.7
± 190.1 |
11,715.3
± 198.0 |
11,500.2
± 199.9 |
11,356.6
± 281.2 |
11,238.9
± 281.4 |
11,168.3
± 281.5 |
11,127.9
± 280.7 |
|
|
Notes:
• CRP was not implemented until 1985.
• Cropland includes cultivated and non-cultivated cropland.
• When the estimate is 0.0, margins of error are not applicable and shown as a dashed line (--).
About the Data
Estimates presented here are based upon the latest information from the
National Resources Inventory (NRI).
The NRI is a longitudinal sample
survey based upon scientific statistical
principles and procedures. It is conducted by the U.S. Department of Agriculture’s Natural
Resources Conservation Service (NRCS),
in cooperation with Iowa State University’s Center for Survey Statistics and Methodology.
These results are based upon the 2017 NRI, which provides nationally consistent
data for the 35-year period 1982–2017.
Current estimates cover the contiguous 48 States, Hawaii, and the Caribbean Area.
Release of NRI results is guided by NRCS policy and is in accordance with OMB
and USDA Quality of Information Guidelines developed in 2001.
NRCS is releasing NRI estimates only when they meet statistical standards and are scientifically
credible in accordance with these policies;
also, measures of statistical uncertainty are provided for all 2017 NRI estimates released to
the public.
The findings on land use come from the NRI data category "Land Cover/Use,"
which comprises mutually exclusive categories such as cropland, rangeland, forest land,
other rural land, developed land, and water areas.
The NRI uses this classification
to account for every acre of non-Federal land within
the Nation. Every parcel of land is described by one and only one of these categories.
The NRI approach
to conducting inventories facilitates examining trends
in rural and developed land uses over time because—
- the same sample sites have been studied since 1982;
- the same data have been collected since 1982 [definitions and protocols
have remained the same];
- the inventory accounts for 100 percent of the surface area;
- quality assurance and statistical procedures are designed/developed to
ensure that trend data are scientifically legitimate and unambiguous; and
- it is easy to track lands as they go from one land-use category to another.
Irrespective of the scale of analysis, margins of error must be considered.
Margins of error (at the 95
percent confidence level) are presented for all NRI estimates.
Note that estimates of change between two points in time will be less precise (relatively)
than estimates for a single
inventory year because the changes will be occurring on a smaller fraction of the landscape.
Glossary
- Land cover/use. A term that includes categories of land cover and categories of
land use. Land cover is the vegetation or other kind of material that covers the land surface. Land
use is the purpose of human activity on the land; it is usually, but not always, related to land cover.
The NRI uses the term land cover/use to identify categories that account for all the surface area of the
United States.
- Cropland. A land cover/use category that includes areas used for the production
of adapted crops for harvest. Two subcategories of cropland are recognized: cultivated and non-cultivated.
Cultivated cropland comprises land in row crops or close-grown crops and also other cultivated cropland,
for example, hayland or pastureland that is in a rotation with row or close-grown crops. Non-cultivated
cropland includes permanent hayland and horticultural cropland.
- Conservation Reserve Program (CRP) land. For NRI, only acres that have been enrolled
in CRP general sign-up are included in the CRP land cover/use category. It does not include acres enrolled under CRP
continuous sign-up.
- Developed land. A combination of land cover/use categories, large urban and
built-up areas, small built-up areas, and rural transportation land.
- Urban and built-up areas. A land cover/use category consisting of residential,
industrial, commercial, and institutional land; construction sites; public administrative sites;
railroad yards; cemeteries; airports; golf courses; sanitary landfills; sewage treatment plants; water
control structures and spillways; other land used for such purposes; small parks (less than 10 acres)
within urban and built-up areas; and highways, railroads, and other transportation facilities if they
are surrounded by urban areas. Also included are tracts of less than 10 acres that do not meet the
above definition but are completely surrounded by urban and built-up land. Two size categories are
recognized in the NRI: areas of 0.25 acre to 10 acres, and areas of at least 10 acres.
- Large urban and built-up areas. A land cover/use category composed of developed
tracts of at least 10 acres—meeting the definition of urban and built-up areas.
- Small built-up areas. A land cover/use category consisting of developed land
units of 0.25 to 10 acres, which meet the definition of urban and built-up areas.
- Rural transportation land. A land cover/use category which consists of all
highways, roads, railroads and associated right-of-ways outside urban and built-up areas; also includes
private roads to farmsteads or ranch headquarters, logging roads, and other private roads (field lanes
are not included).
- Forest land. A land cover/use category that is at least 10 percent stocked by
single-stemmed woody species of any size that will be at least 4 meters (13 feet) tall at maturity.
Also included is land bearing evidence of natural regeneration of tree cover (cut over forest or
abandoned farmland) and not currently developed for nonforest use. Ten percent stocked, when viewed
from a vertical direction, equates to an areal canopy cover of leaves and branches of 25 percent or
greater. The minimum area for classification as forest land is 1 acre, and the area must be at least
100 feet wide.
- Pastureland. A land cover/use category of land managed primarily for the
production of introduced forage plants for livestock grazing. Pastureland cover may consist of a
single species in a pure stand, a grass mixture, or a grass-legume mixture. Management usually
consists of cultural treatments: fertilization, weed control, reseeding or renovation, and control of
grazing. For the NRI, includes land that has a vegetative cover of grasses, legumes, and/or forbs,
regardless of whether or not it is being grazed by livestock.
- Rangeland. A land cover/use category on which the climax or potential plant cover
is composed principally of native grasses, grasslike plants, forbs or shrubs suitable for grazing and
browsing, and introduced forage species that are managed like rangeland. This would include areas where
introduced hardy and persistent grasses, such as crested wheatgrass, are planted and such practices as
deferred grazing, burning, chaining, and rotational grazing are used, with little or no chemicals or
fertilizer being applied. Grasslands, savannas, many wetlands, some deserts, and tundra are considered to
be rangeland. Certain communities of low forbs and shrubs, such as mesquite, chaparral, mountain shrub, and
pinyon-juniper, are also included as rangeland.
- Other rural land. A land cover/use category that includes farmsteads and other
farm structures, field windbreaks, barren land, and marshland.
- Water areas. A land cover/use category comprising water bodies and streams that
are permanent open water.
- Federal land. A land ownership category designating land that is owned by the Federal
Government. It does not include, for example, trust lands administered by the Bureau of Indian Affairs or
Tennessee Valley Authority (TVA) land. No data are collected for any year that land is in this ownership.
- Prime farmland. 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.
- Margins of Error. Margins of error are reported for each NRI estimate. The margin
of error is used to construct the 95 percent confidence interval for the estimate. The lower bound of
the interval is obtained by subtracting the margin of error from the estimate; the upper bound is
obtained by adding the margin of error to the estimate. Confidence intervals can be created for various
levels of significance which is a measure of how certain we are that the interval contains the true
value we are estimating. A 95 percent confidence interval means that in repeated samples from the same
population, 95 percent of the time the true underlying population parameter will be contained within the
lower and upper bounds of the interval.
For more definitions see the full
2017 NRI Glossary
More Information
For more information about the NRI, visit
http://www.nrcs.usda.gov/technical/NRI/
Send comments and questions to the NRI Help Desk
The data in this report can be
downloaded here
Return to the
RCA Interactive Data Viewer
Citation for this website:
U.S. Department of Agriculture. 2017.
2017 National Resources Inventory.
Natural Resources Conservation Service, Washington, DC. 31 October 2020 *
<http://www.nrcs.usda.gov/Internet/NRCS_RCA/reports/nri_oh.html>
*[use date the website was accessed]
|