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Review the indicators
at a glance
Biological Components
Four indicators describe the biological condition of farmlands.
Continuing from the three soil indicators noted above, the first
biological indicator measures the condition of microscopic animals
in cropland soils. The second indicator focuses on the wildlife
that live in the farmland landscape, a third reports on native and
non-native plants in those parts of the farmland landscape that
are not used for production, and a fourth measures stream habitat
quality—the sediments in the streambed, the stability of stream
banks, and similar physical attributes. The latter three indicators
require additional development.
- What is the condition of the microscopic animal communities
in cropland soils? The condition of nematodes (roundworms)
in the soil is a good indicator of overall soil condition. Data
are not adequate for national reporting on this indicator.
- What is the condition of wildlife in areas that are heavily
dominated by farmlands? Additional work is necessary to develop
an indicator that describes the condition of species that prosper
in the farmland landscape and of those that depend on the kind
of habitat that existed before conversion to agriculture.
- In areas that are heavily dominated by croplands, is most
of the remaining noncropland vegetation native or non-native?
Non-native vegetation often provides less suitable wildlife habitat.
This indicator requires further development.
- What is the quality of the habitat in streams in farmland
regions? Stream habitat quality often reflects the effects
of activities, including farming practices, in the watershed.
This indicator requires further development.
Human Use
Four indicators measure the human use of farmlands. Three focus
on aspects of production: the first tracks changes in the yield
per acre for five major crops; the second tallies total agricultural
output and changes in the inputs, such as fertilizer and labor,
used to produce farm goods; and the third focuses on the dollar
value of farm sales, which depends on both the amount of goods produced
and the prices farmers receive. The fourth indicator focuses on
another human use of farmlands, recreation.
- How has the per-acre yield of major crops changed over time?
Since 1950, per-acre yields of corn, wheat, and cotton have more
than doubled, with corn yield increasing almost fourfold. Of major
crops, soybean yields went up the least, but still nearly doubled.
- How have farm output and the inputs (pesticides, fertilizers,
labor, land, etc.) needed to produce that output changed over
time? U.S. agricultural output has been increasing steadily
since 1950, while the major inputs required to produce a unit
of output—with the exception of pesticides—have decreased.
Pesticide use has leveled off since 1980.
- What is the value of the nation’s production of crops
and livestock? The gross value of agricultural output
(adjusted for inflation) was about $235 billion in 2004, or about 28% more than in 1950. Over the past half-century,
however, there have been major fluctuations, from a low of
about $160 billion in 1957, to a high of $290 billion in 1973.
Livestock sales have consistently accounted for about half
of all agricultural value.
- How much recreation takes place on farmlands? A considerable
amount of recreation takes place on farmlands—hunting and
fishing, for example—and some farmers depend on income from
such activities. Data are not adequate to report nationally on
this indicator.
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