Change in Prime Farmland Acreage, 1982-1997

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Description

This dot map shows gains and losses of Prime Farmland over the period of 1982-1997 aggregated by and placed randomly within 8-digit hydrologic units. One dot represents 2,000 acres. Red dots denote losses in Prime Farmland totaling 10.7 million acres; green dots denote gains in Prime Farmland totaling 0.7 million acres.

Cautions for this Product:
This map may not be used for site-specific information. The data have been aggregated such that dots are placed by 8-digit hydrologic units within each state. Data are not collected on Federal land. Data are not available for Alaska or the Pacific Basin. Data for Puerto Rico and the U.S. Virgin Islands are aggregated by 6- digit hydrologic unit.

Sources

Source: National Resources Inventory, 1997
Distributor: USDA-NRCS-RIAD
Reliability:
NRI sample data are generally reliable at the 95% confidence interval for state and certain broad substate area analyses. Generally, analyses that aggregate data points by smaller geographic areas and/or more specific criteria result in fewer data points for each aggregation and therefore less reliable estimates. NRI maps reflect national patterns rather than site- specific information.

Layers

Aggregate Layer: Cross of State with 8 Digit Hydrologic Units and Federal Land Other Layers Displayed: States, Rivers

Definitions

Non-Federal land:
Includes all land and water areas where the ownership is by private, municipal, county or parish, state, Indian tribal, individual trust, the Tennessee Valley Authority, or areas under temporary control of a Federal, state, county or municipal agency or government for foreclosure or nonpayment of taxes.

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. It has the soil quality, growing season, and moisture supply needed to produce economically sustained high yields of crops when treated and managed according to acceptable farming methods, including water management. 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.[SSM, USDA Handbook No. 18, October 1993]

Product Information

Product ID: 5271
Production Date: 5/7/01
Product Type: Map

For additional information contact the Resources Inventory and Assessment Division. Please include the Product ID you are inquiring about. nri@wdc.usda.gov or 1400 Independence Avenue SW - P.O. Box 2890 - Washington D.C. 20013. If you use our analysis products, please be aware of our disclaimer.