Agriculture has always depended on soil, water, air, and other
natural resources and has always had a profound impact on the environment.
Despite the increased focus on environmental issues during the
last half of the 20th century, it wasn’t always easy to find
basic facts about resource use in agriculture and environmental
impacts associated with agricultural production. Nearly 10 years
ago, ERS addressed that problem with the release of Agricultural
Resources and Environmental Indicators, known as AREI.
The third and latest edition of the report, available as an online
document only, continues to expand on the information contained
in the original and is updated as new data become available. Coverage
includes land, water, and a variety of other resources, practices,
and policies.
Land resources—Grassland pasture and range,
followed by forest, each account for over 25 percent of U.S. land
use, while cropland comes in third with 20 percent. While urbanized
land has quadrupled since 1945, it still makes up less than 3.5
percent of the U.S. land base and is not an overall threat to food
production. Besides food, rural land provides many other amenities
(such as open space, scenic views, wildlife habitat, and recreation)
that are driving farmland preservation efforts. While land quality
can be degraded by soil erosion, conservation efforts have substantially
reduced the problem on agricultural lands.
Water resources—Irrigation of crops is
the dominant use of fresh water in the U.S., but agriculture’s
share is dropping as urban and environmental demands for water
increase. While only about 15 percent of U.S. harvested cropland
is irrigated, this portion provides about 40 percent of the total
value of crops produced. Water runoff from agricultural lands often
carries sediment and nutrients and other chemicals into water bodies
and groundwater. Various Federal and State programs are directed
toward water conservation and quality preservation.
Biological resources— Some biological resources
affect agriculture (such as cultivated plants and pollinators),
some provide scientific input (such as genetic resources for plant
breeding and biotechnology), and some are natural goods and services
(such as wildlife, fish, and scenic beauty). While often difficult
to value, these resources make an increasingly recognized contribution
to society, and are the focus of national and international efforts
to preserve and enhance that contribution.
AREI also has chapters on soil, nutrient, and pest management;
agricultural productivity and research; domestic conservation
and environmental polices; and U.S. agriculture and global resources.