Total Erosion on Cropland and CRP
Description
This graphic shows the total tons of erosion on
cropland and CRP land for the years 1982, 1987,
1992, 1995, and 1997.
Cautions for this Product:
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.
Definitions
Conservation Reserve Program (CRP):
A Federal program established under the Food
Security Act of 1985 to assist private
landowners to convert highly erodible cropland
to vegetative cover for 10 years. [NMCSP]
Cropland:
A Land cover/use category that includes areas
used for the production of adapted crops for
harvest. Two subcategories of cropland are
recognized: cultivated and noncultivated.
Cultivated cropland comprises land in row crops
or close-grown crops and also other cultivated
cropland, for example, hayland or pastureland
that is in a rotation with row or close-grown
crops. Noncultivated cropland includes permanent
hayland and horticultural cropland. [NRI-97]
Erosion:
The wearing away of the land surface by running
water, waves, or moving ice and wind, or by such
processes as mass wasting and corrosion
(solution and other chemical processes). The
term "geologic
erosion" refers to natural erosion processes
occurring over long (geologic) time spans.
"Accelerated
erosion" generically refers to erosion that
exceeds what is presumed or estimated to be
naturally occurring
levels, and which is a direct result of human
activities (e.g., cultivation and logging).
[NSSH-96]
Universal soil loss equation (USLE):
This equation estimates average annual soil loss
from sheet and rill erosion. Location specific
data for the field in which the NRI point falls
or that portion of the field surrounding the
point that would be considered in conservation
planning are used in the NRI calculations. The
equation is: A = RKLSCP, where A is the
computed soil loss per unit area, R is a
rainfall factor, K is a soil erodibility factor,
L is a slope length factor, S is a slope-
steepness factor, C is a cover and management
factor, and P is a conservation practice
factor. [NAM]
Water Erosion:
The process of detachment, transport and
deposition of soil in which the primary agent is
water. This may include sheet, rill and gully
erosion; however, for the purposes of this
analysis, unless otherwise stated, water erosion
refers only to sheet and rill erosion and
excludes gully erosion.
Wind erosion:
The process of detachment, transport, and
deposition of soil by wind. [NAM]
Wind erosion equation (WEQ):
An erosion model designed to predict long-term
average annual soil losses from a field having
specific characteristics (NAM). E= f(IKCLV)
where E is the estimated average annual soil
loss expressed in tons per acre per year; I is
the soil erodibility; K is the soil ridge
roughness factor; C is the climatic factor; L is
the equivalent unsheltered distance across the
field along the prevailing wind erosion
direction; and V is the equivalent vegetative
cover. [NAM]
Product Information
Product ID:
5848
Production Date:
12/19/00
Product Type:
Chart
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.
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