Documentation

Much of the information here is excerpted or adapted from the USDA, Economic Research Service report, Major Uses of Land in the United States, 2017 (EIB-275) September, 2024.

Data Sources

The USDA, Economic Research Service's (ERS) Major Land Use (MLU) series is the longest running, most comprehensive accounting of all major uses of public and private land in the United States. The series was started in 1945. Data from USDA, Forest Service, USDA, National Agricultural Statistics Service, USDA, Natural Resources Conservation Service, and USDA, Farm Service Agency, the U.S. Department of Commerce, Bureau of the Census (Census Bureau), U.S. Department of the Interior, Bureau of Land Management, U.S. Geological Survey, and other sources were compiled by State to estimate the uses of several broad classes and subclasses of land. Standardized procedures were used to develop the estimates and are outlined below.

Scope/Coverage of the Data

The MLU series provides national as well as State land-use estimates for all 50 States. Estimates of land in all uses are published at roughly 5-year intervals, coincident with the Census of Agriculture going back to 1945. Additionally, cropland used for crops is updated annually and provided in table 3 of the data product.

Methods and Definitions

Definitions, sources of data, and estimation techniques have varied little over time in the Major Land Uses series. The following definitions and explanations of the data are for the most recent year, but generally apply to all previous years as well.

Cropland—Total cropland is the sum of five components, including (1) cropland harvested (net of double cropping), (2) crop failure, (3) cultivated summer fallow, (4) cropland pasture, and (5) idle cropland.

Cropland used for crops—The sum of three of the cropland components, including (1) cropland harvested (net of double cropping), (2) crop failure, and (3) cultivated summer fallow. Represents the land used as an input for crop production. Sources for this data are U.S. Department of Agriculture (USDA), National Agricultural Statistics Service’s (NASS) Census of Agriculture and Crop Production annual summary.

Cropland harvested—Includes all row crops and closely sown crops; hay and silage crops; tree fruits, small fruits, berries, and tree nuts; vegetables and melons; and miscellaneous other minor crops. Also includes land used to produce Christmas trees. Cropland that was harvested more than once in a single year (i.e., double cropped) is only counted once. Represents the land area on which crops are grown.

Crop failure—The difference between the area planted, with the intention of harvesting and the area harvested. Thus, the acreage planted to cover crops and soil-improvement crops (not intended for harvest) is excluded from crop failure and is considered idle. Consists mainly of the acreage on which crops failed because of weather, insects, and diseases, and includes some land not harvested due to lack of labor, low market prices, or other factors.

Cultivated summer fallow—Cropland in subhumid areas of the West region that are cultivated for one or more seasons to control weeds and accumulate moisture before small grains are planted. This practice is optional in some areas but is a requirement for crop production in the drier cropland areas in the West. Other types of fallow (such as cropland planted to soil-improvement crops but not harvested and cropland left idle all year) are not included in cultivated summer fallow but are included as idle cropland. Occasionally referred to in this report simply as summer fallow, fallow, or fallowed.

Cropland pasture—Grazed land on which no crops were harvested this year but is considered to be in long-term crop rotation and/or could have been cropped without additional improvement. Cropland pastured before or after crops were harvested is included as cropland harvested and not cropland pasture. While the MLU's definition of cropland pasture has not changed, methodological changes in the 2007 and 2012 USDA, Censuses of Agriculture have led to a large portion of what had previously been classified as cropland pasture being reclassified as permanent grassland pasture and range. See the updates/revisions section and appendix D of the report, Major Uses of Land in the United States, 2017 (EIB-275) for more details.

Idle cropland—Includes land in cover and soil-improvement crops, as well as cropland on which no crops were planted. Also includes land enrolled in USDA, Farm Service Agency’s Conservation Reserve Program (CRP), Wetlands Reserve Program (WRP), and Agricultural Conservation Easement Program Wetland Reserve Easements (ACEP-WRE), with CRP land used for emergency haying and grazing in that year excluded.

Grassland pasture and range—All open land used primarily for pasture and grazing (including shrub and brushland types of pasture, grazing land with sagebrush, and scattered mesquite) and all tame and native grasses, legumes, and other forage used for pasture or grazing. Consists of private grazing land (not including cropland or forestland) and Federal grazing lands leased to the public. Also includes lands managed by the U.S. Department of the Interior, Bureau of Land Management, and nonforested lands managed by the U.S. Department of Agriculture, U.S. Forest Service. The primary source for this land-use category is USDA, Natural Resources Conservation Service’s National Resources Inventory (NRI). As the NRI only contains non-Federal land, other sources are used to obtain Federal land used for this category. For Federal grassland pasture and range data, sources such as U.S. Department of the Interior, Bureau of Land Management and the USDA, Forest Service are used.

Forest-use land—Land that serves commercial forest uses, as opposed to land that has forest cover but is used for other purposes. Thus, this land does not include forestland in parks, wildlife areas, or other special uses, which are included in the special uses category. This land is the sum of grazed forest and ungrazed forest-use land. The primary source for this data is the USDA, Forest Service’s Forest Resources of the United State report.

Grazed forest-use land—Non-Federal forestland that has grass or other forage growth, plus forested land that is leased out for grazing by the USDA, U.S. Forest Service. Non-Federal forestland is sourced from USDA, Natural Resources Conservation Service’s National Resources Inventory (NRI).

Ungrazed forest-use land—Forest-use land that is not used for grazing. Calculated as the remaining forest-use land after account for grazed forest-use land.

Special uses—Includes land in rural transportation, rural parks and wildlife areas, national defense and industrial areas, and farmsteads.

Rural transportation—Area covered by rural highways, roads, railways, and airports (excluding military bases).

Rural parks and wildlife—Areas in national and State park systems; designated areas owned by the USDA, U.S. Forest Service, and the U.S. Department of the Interior, Bureau of Land Management; and areas administered by the U.S. Department of the Interior, U.S. Fish and Wildlife Service and State wildlife agencies.

National defense and industrial—Areas administered by the U.S. Department of Defense and the U.S. Department of Energy.

Farmsteads—Housing and roads on farms.

Urban areas—Urban areas in the MLU series follow the U.S. Department of Commerce, Bureau of the Census’s (Census Bureau) urban-area definition. The Census Bureau compiles urban areas every 10 years, coincident with the Census Bureau’s Census of Population. Census urban areas include densely populated areas with at least 50,000 people (or urbanized areas) and densely populated areas with 2,500–50,000 people (or urban clusters). Densely populated areas include census blocks with a population density of at least 1,000 people per square mile, surrounding blocks with a density of at least 500 people per square mile, and "less densely settled blocks that form enclaves or indentations or are used to disconnect discontinuous areas with qualifying densities" (U.S. Department of Commerce, Bureaus of the Census, 2010). In the 2000 Census, urban clusters replaced previous designations that were based on the boundaries of census-designated places. The 2000 Census’s urban-area definition includes residential areas and concentrations of nonresidential urban areas, such as commercial, industrial, and institutional land; office areas; urban streets and roads; major airports; urban parks and recreational areas; and other land within urban-defined areas. The definition allows for exceptions and special cases. Portions of extended cities that are essentially rural in character are excluded. For the MLU series, intercensus years are extrapolated based on the prior two censuses.

Miscellaneous other land—Includes miscellaneous other uses such as land in cemeteries, golf courses, mining areas, quarry sites, marshes, swamps, sand dunes, bare rocks, deserts, tundra, and other unclassified land, as well as some—but not all—industrial, commercial, and residential sites in rural areas. Land in this category is equal to the remaining land in each State after all other land-use categories have been reconciled.

Strengths and Limitations

In addition to its breadth and scope, the MLU’s strength is that it accounts for each and every acre of U.S. land. This is done in a mutually exclusive way such that each acre is classified as one of our major land-use categories. In order to make the sum of all categories equal the total land area for each State, a reconciliation process takes places where the numbers reported in our source data are occasionally adjusted to avoid double counting (i.e. land getting classified as two different land-use categories across different sources). This means that our estimates for a specific land-use type may not always perfectly match other official estimates. In cases where individuals are interested in one specific land use, rather than the use of all land, we recommend using the underlying official source. The only exception to this is the cropland used for crops variable, for which the MLU is the definitive source, and these estimates are not modified from their original reported values.

While these estimates can be used to identify long-term trends in land uses at the State level, there are also challenges that can make year-to-year comparisons unreliable for a particular component of MLU categories across specific years. In general, more confidence should be put in the broader land-use trends over decades rather than specific 5-year fluctuations. The primary reason for this challenge is methodological changes made by the data collectors and/or providers. Notable examples of methodological changes include in the USDA, National Agricultural Statistics Service's (NASS) 2007 and 2012 Census of Agriculture method for collecting cropland pasture acreage data; changes in the U.S. Department of Commerce, Bureau of the Census’s definition of urban areas in 2000; and the U.S. Forest Service’s changes in 2012 to the in-situ height requirement (13.1 to 16.4 feet) for what constitutes a tree as described in the Resources Planning Act (RPA) Assessment. These are described in detail below.

Change in Urban Definition

Urban estimates before and after 2000 are not directly comparable due to a change in the definition of urban areas in the 2000 Census of Population and Housing. The decrease in MLU "urban" acreage estimates between 1997 and 2002 should be viewed as a consequence of this definitional change, rather than reflecting a decline in acreage. See the report, Major Uses of Land in the United States, 2017 (EIB-275) for more details.

Change in Cropland Pasture Methodology

Cropland pasture estimates declined by nearly 79 percent in the 10 years between 2002 and 2012 after exhibiting relative stability for more than 50 years. This decline is largely attributable to methodological changes in the collection of cropland pasture data in USDA, NASS' Census of Agriculture, the data source for the cropland pasture category. In USDA, NASS’ 2002 Census of Agriculture, respondents were asked to report the acreage of "Cropland used only for pasture or grazing (include rotation pasture and grazing land that could have been used for crops without additional improvements)." This was the second item in the land-use section of the census questionnaire, falling under the broad heading of "Cropland" and immediately following the question about harvested cropland. In 2007, the wording of the cropland pasture question in the Census was identical to that used in 2002, but the question was moved from the second (of five) items in the Cropland section to the last (of three) items in the Pasture section. In USDA, NASS’ 2012 Census of Agriculture, additional changes were made. While the cropland pasture question remained in the same place as in 2007, the wording was changed to: "Other pasture and grazing land (including rotational pasture) that could have been used for crops without additional improvements." There is no way to definitively determine the extent of the effects of changes in the placement and wording of the cropland pasture question on estimates of cropland pasture used here. However, it seems likely (given the relatively stable cropland pasture acreage trend from 1949 to 2002) that these changes contributed to the large decrease between 2002 and 2012. However, the wording and placement of this question in 2017 were identical to that of 2012, allowing us to directly compare recent trends in cropland pasture once more. A table comparing the wording, placement, and reported values for the cropland pasture question in the Census of Agriculture between 1997 and 2017 can be found in appendix D of the report, Major Uses of Land in the United States, 2017.

Change in Forestland Definition

From 2007 to 2012 there was a 39-million acre decrease in forest-use land. However, it is impossible to tell how much of this 39-million-acre decrease was the result of true land changes and how much was the result of the underlying data (i.e., the Resources Planning Act (RPA) Assessment) that changed the in situ height requirement of what constitutes a tree from 13.1 to 16.4 feet in 2012 to be consistent with the United Nations Food and Agriculture Organization (FAO) internationally agreed-upon definition

Updates and Revisions

The most recent (2017) inventory of U.S. major land uses saw minor adjustments to methodology and newly discovered errors from previous years were corrected.

Methodological Updates

For the 2017 MLU, we switched from collecting data on State wildlife areas by hand for each State to using the amount of State fish and wildlife acreage reported in the U.S. Geological Survey’s Protected Areas Database (PAD-US). We also used PAD-US to estimate acreage managed by the U.S. Department of Energy.

Corrections

In updating the 2017 MLU, some calculation errors in summing grazed and ungrazed forest acres were discovered in the total forest land data for earlier years in the Northeast region. The errors in general increased total forest land for certain Northeastern States, the region, and the national level but did not affect total land at the State, region, or national level. The following corrections were made:

For 1987, we added 250 thousand acres of forest-use land to Massachusetts (resulting in a 9-percent change), 100 thousand acres of forest-use land to New Jersey (a 6-percent change), and 25 thousand acres of forest-use land to Connecticut (a 1-percent change). Cumulatively, these changes added 375 thousand acres to the Northeast (a 1-percent change) but resulted in less than 1-percent change at the 48-State and national levels. For 1992, we added 100 thousand acres (3.7 percent) to Massachusetts, 5 thousand acres (1.3 percent) to Rhode Island, and 25 thousand acres (1.5 percent) to Connecticut, for a net addition of 130 thousand acres of forest-use land at the Northeastern region (0.2 percent) and 48-State, and national totals (both less than 0.1 percent). We also adjusted forest-use ungrazed land by adding 133 thousand acres (3.2 percent) to Vermont and subtracting 100 thousand acres (5.4 percent) to New Jersey, for a net addition of 33 thousand acres of forest-use ungrazed land to the Northeastern region, 48-State, and national totals (all less than 0.1 percent).

Additional changes to 1992 data include an increase in New Jersey special use land by 10 thousand acres (1.4 percent) with no implications for regional aggregates, and updated urban use land acres by decreasing Massachusetts urban use land by 37 thousand acres (2.6 percent), decreasing Connecticut urban land by 37 thousand acres (4.4 percent), and decreasing New Jersey urban use land by 40 thousand acres (3.1 percent), for a total decrease of urban land by 114 thousand acres for the Northeast region (1.2 percent), and the 48-State total and the national total (both less than 0.1 percent change).

We made similar adjustments for 1997, adding 200 thousand acres of forest-use land to the previous level in Massachusetts (an 8-percent change), adding 125 thousand acres of forest-use land to Connecticut (an 8-percent change) and adding 20 thousand acres to Rhode Island (a 6-percent change). The aggregate 345 thousand acres of forest-use land were added to the Northeast (a 1-percent change) but resulted in less than 1-percent change at the 48-State and national levels.

We also corrected another error we discovered at that time in which the listed total acres for rural transportation in the Northeast region for 2007 was not the correct sum of the individual Northeast States values. To correct this we updated the 2007, Northeast, regional transportation value to be the correct sum of all the Northeast States. The corrected value is 1,729 thousand acres, a change of 123 thousand acres or 7.7 percent.

Additional Resources

For more information on how the Major Land Uses estimates compare to other federal land use and land cover datasets, see Land Use and Land Cover Estimates for the United States. For citations of the previous MLU reports, see Major Land Use Reports Since 1948.

Recommended Citation

U.S. Department of Agriculture, Economic Research Service. (2024). Major land uses data product.