2015 National Resources Inventory

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 lands include privately owned lands, tribal and trust lands, and lands controlled by state and local governments.

National Cropland


Cropland Use
In thousands of acres, with margins of error
Cropland Use 1982 1987 1992 1997 2002 2007 2012 2015
Irrigated Cultivated Cropland 49,845.7
± 879.4
± 1,012.1
± 979.1
± 1,035.8
± 1,311.5
± 1,200.5
± 1,212.2
± 1,211.4
Nonirrigated Cultivated Cropland 326,433.8
± 2,107.7
± 1,971.0
± 1,981.0
± 2,238.8
± 2,268.4
± 2,335.3
± 2,311.5
± 2,435.1
Total Cultivated Cropland 376,279.5
± 2,219.1
± 2,108.9
± 2,011.3
± 2,061.8
± 2,117.9
± 2,154.7
± 2,089.8
± 2,213.9
Irrigated Noncultivated Cropland 12,232.2
± 517.3
± 534.0
± 583.8
± 623.2
± 752.0
± 797.4
± 777.4
± 754.0
Nonirrigated Noncultivated Cropland 31,887.6
± 611.2
± 710.6
± 644.3
± 663.7
± 836.3
± 922.0
± 755.8
± 762.9
Total Noncultivated Cropland 44,119.8
± 827.0
± 918.1
± 879.1
± 1,002.4
± 1,131.5
± 1,261.5
± 975.2
± 1,075.3
Total Cropland 420,399.3
± 2,079.8
± 1,989.9
± 1,991.1
± 2,032.0
± 2,011.7
± 2,157.5
± 2,100.3
± 2,318.9
Cultivated and Noncultivated Cropland bar chart, see Cropland Use table for data values
• Cropland includes cultivated and noncultivated cropland.

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 2015 NRI, which provides nationally consistent data for the 30-year period 1982–2015. 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 2015 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.


  • 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 noncultivated. 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. Noncultivated cropland includes permanent hayland and horticultural cropland.
      • Close-grown crops. Crops that are generally drill-seeded or broadcast, such as wheat, oats, rice, barley, and flax.
      • Row crops. A subset of the land cover/use category cropland (subcategory, cultivated) comprising land in row crops, such as corn, soybeans, peanuts, potatoes, sorghum, sugar beets, sunflowers, tobacco, vegetables, and cotton.
      • Hayland. A subcategory of cropland managed for the production of forage crops that are machine harvested. The crop may be grasses, legumes, or a combination of both. Hayland also includes land in set-aside or other short-term agricultural programs.
      • Horticultural cropland. A subcategory of cropland used for growing fruit, nut, berry, vineyard, and other bush fruit and similar crops. Nurseries and other ornamental plantings are included.
  • Irrigated land. Land that shows evidence of being irrigated during the year of the inventory or of having been irrigated during 2 or more of the last 4 years. Water is supplied to crops by ditches, pipes, or other conduits. For the purposes of the NRI, water spreading is not considered irrigation.
    • Water spreading. Diverting or collecting runoff from natural channels, gullies, or streams with a system of dams, dikes, ditches, or other means, and spreading it over a relatively flat area. (See Irrigated land.)
  • 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 2015 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

Citation for this website:
U.S. Department of Agriculture. 2015.
2015 National Resources Inventory.
Natural Resources Conservation Service, Washington, DC. 31 October 2018 *

*[use date the website was accessed]