1997 National Resources Inventory - Highlights

Background

The National Resources Inventory (NRI) is a statistically based survey that has been designed and implemented using scientific principles to assess conditions and trends of soil, water, and related resources on non-Federal lands in the United States.

The NRI is conducted by the U.S. Department of Agriculture's Natural Resources Conservation Service in cooperation with the Iowa State University Statistical Laboratory.

The NRI is a compilation of natural resource information on non-Federal land in the United States - nearly 75 percent of the Nation's total land area. The 1997 NRI captures data on land cover and use, soil erosion, prime farmland soils, wetlands, habitat diversity, selected conservation practices, and related resource attributes at more than 800,000 scientifically selected sample sites. The 1997 NRI covers all 50 States, Puerto Rico, the U.S. Virgin Islands, and some Pacific Basin locations.

Land Use

Federal land totaled about 402 million acres in 1997. Non-Federal land amounted to just under 1.5 billion acres, most of it rangeland (27 percent), forestland (27 percent), followed by cropland (25 percent), pastureland (8 percent), and developed land (about 7 percent). Land use is not static, however. It is surprisingly dynamic, with annual shifts in and out of different uses.

In agriculture there are constant shifts in the use of land among cropland, pasture, range, and forested land to meet production needs, implement rotations of land in and out of cultivation, and adjust to needs for maintenance and sustainability of soil resources.

Since 1982, cropland including land enrolled in the Conservation Reserve Program (CRP) declined 13 million acres, pastureland declined just under 14 million acres; rangeland declined 12 million acres; and forestland increased by 800,000 acres. The largest increase in acreage by land use was for development, almost 30 million acres, from 5 percent of the land area in 1982 to more than 7 percent in 1997.

Urbanization and Development

Agricultural land conversion used to be thought of as happening only around major metropolitan areas such as Los Angeles, Atlanta, Chicago, and the Eastern corridor from Washington, D.C., to New York. However, more small- and mid-sized cities are experiencing rapid development and the consequent concerns associated with community growth.

Developed land totaled only about 7 percent of the non-Federal land area in 1997; however, from 1992-97 more land was developed (nearly 16 million acres) than during 1982-92 (more than 13 million acres). Growth and prosperity in non-agricultural sectors of the economy have been dominant forces in the expansion of developed areas.

Although not considered a threat to food production nationally, urbanization and development leads to the fragmentation of agricultural land and the loss of prime farmland in growing areas. From 1992-97, the national rate of development more than doubled to 3 million acres per year.

Irrigation

The number of irrigated acres continued to decline in the West and South Central States, while increasing in the Midwest, Northern Plains, East, and Southeast.  States with the largest decreases in irrigation since 1982 were Texas, California, New Mexico, Nevada, and Idaho. Largest increases since 1982 were in Arkansas, Nebraska, Mississippi, Missouri, Michigan, and North Carolina. Regional decreases were greatest in the Southern Plains, Pacific, and Mountain States while the greatest increases were in the Delta, Northern Plains, Corn Belt, Appalachian, Northeastern, and Great Lake States.

The biggest shifts in redistribution of irrigated acres occurred between 1987 and 1992; it continued, but slowed, into the 1992-97 period in every region except the Lake States (driven by decreases in Minnesota) and the Southeast (driven by decreases in Florida and Georgia). Competition for water, the economics of production agriculture, and risk management to ensure crop production to compensate for shortages of rainfall have driven regional shifts in demand for irrigation.

In the future, continued severe and prolonged droughts may lead to concerns about surface and groundwater withdrawals in irrigation growth areas. This may lead to water supply issues in areas where they have not been major concerns in the past.

Erosion

Since 1982, erosion on cropland and CRP land has been reduced by 38 percent.  Stewardship by agricultural producers and private landowners on the Nation's working lands hit an all-time high with successful implementation of the 1985 and 1990 Farm Bills.

Since 1995 though, erosion has leveled off at about 1.9 billion tons per year; 112 million acres (30 percent of cropland) has been determined to be excessively eroding at rates of 1.3 billion tons per year. Excessive erosion continues to be a serious problem in many parts of the country.

More than 60 million acres of fragile highly erodible cropland was determined to have excessive erosion, and nearly 52 million acres of non-highly erodible cropland was determined to have erosion that exceeded the tolerable soil loss rate.

Excessive erosion of 1.3 billion tons per year leads to concerns about sediments, nutrients, and pesticides impacting water quality as well as air quality in wind erosion areas of the West, Midwest, Northern Plains, and Southern Plains.

Excessive erosion also indicates lost opportunities to improve soil quality, sequester carbon dioxide, and reach goals to reduce greenhouse gases in the atmosphere.

Grazing Lands

Maintaining and improving the amount and condition of grazing lands is important for sequestering greenhouse gases, protecting water quality and quantity, providing vegetation for livestock and wildlife, as well as enhancing wildlife habitat and the landscape.

The Nation's grazing lands total 583 million acres and include pastureland, rangeland, and grazed forestland. Together, pasture and rangeland amount to nearly 523 million acres, or 35 percent, of non-Federal land.

Since 1982, total pastureland and rangeland has declined by nearly 26 million acres. From 1992-97, because of changes in land use, the combined decline in pastureland and rangeland acreage was nearly 10 million acres-28 million acres were converted from pastureland and rangeland to other uses, while 18 million acres were converted to pastureland and rangeland. Development accounted for nearly 17 percent of decreases in pastureland and rangeland. Shifts in usage from pastureland and rangeland to development and cultivation caused dramatic changes in the conditions and hydrology of cropland.

Most of the decreases and increases in pastureland and rangeland acreage involved conversion from or conversion to cultivated cropland. Twenty-two percent of decreases in pastureland and rangeland resulted in increases in the amounts of cultivated cropland. The 40 percent increase in pastureland and rangeland came from cultivated cropland.

Wetlands

Wetlands are a vital natural resource that provide flood protection and enhance water quality, wildlife habitat, and air quality. One of USDA's goals is to work with landowners to protect, restore, and enhance wetlands.

Preliminary analysis of the 1997 NRI indicates that from 1992-97 the average wetland loss on agricultural land (cropland, pastureland, and CRP land) was about 54,000 acres per year. About two-thirds of the total losses are due to activities designed to enable or enhance agricultural production, the rest to nonagricultural activities. There was an average annual gain of 30,000 acres during the same period, the result of programs designed to restore or enhance wetlands-such as the Wetlands Reserve Program, as well as State, local, and private initiatives.

As a comparison the 1992 NRI showed an annual loss of 31,000 acres of wetlands on agricultural land from 1982-92 and an annual gain of 4,000 acres.

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