Estimates of nitrogen-fertilizer sales for the conterminous United States in 1985

NITROGEN-FERTILIZER SALES DATA Estimates of nitrogen-fertilizer sales by
county were generated by the U.S. Environmental Protection Agency (1990) and by
Jerald Fletcher (West Virginia University, written commun., 1992) by using the
following procedure: (1) compiling annual State fertilizer-sales data reported
as tonnages to the National Fertilizer and Environmental Research Center of the
TVA; (2) calculating the ratio of expenditures for commercial fertilizers by
county to expenditures for commercial fertilizers by States from the 1987
Census of Agriculture (U.S. Department of Commerce, 1989a); and (3) computing
annual county-level nitrogen-fertilizer sales, in tons, by multiplying
estimates of annual States sales by the ratio of county expenditures to States
expenditures. In some counties no fertilizer sales were reported, but some
fertiliz use was reported in the Census Data. Although fertilizer expenditures
estimates (in $1,000) represent the 1987 growing year, the nitrogen-fertilizer
sales estimates (tons) generally reflect 1985 amounts. Estimates of
nitrogen-fertilizer sales by county were constructed fro a combination of data
reported to State regulatory agencies and from data in the 1987 Census of
Agriculture. Fertilizer-sales data submitted annually to State regulatory
agencies by fertilizer dealers reflect total sales without regard to the land
use for which it was bought, or the State (or county) in which the fertilizer
was actually used. In the Census of Agriculture sampling and statistics were
used to account for non responding farm operations (U.S. Department of
Commerce, 1989b) Thus, the information that describes county-level fertilizer
sales is subject to sampling variability as well as reporting and coverage
errors. Census disclosure rules also prevent the publication of information
that would reveal the operation of individual farms. COUNTY BOUNDARIES The
original files for this map were provided in 15 sections. Boundaries near the
edges of sections have been adjusted in edgematching. Polygons that extend
into the water (an ocean or the Great Lakes) should be considered arbitrary.
Originating_Center: (required) Group: Reference End_Group Group: Summary

The nitrogen-fertilizer sales estimates in this coverage are intended for use
in estimating regional fertilizer sales, and in producing visual displays and
mapping relative rates of fertilizer sales across broad regions of the United
States.

This coverage contains estimates of nitrogen-fertilizer sales for the
conterminous United States in 1985 as reported by the U.S. Environmental
Protection Agency (1990) and by Jerald Fletcher (West Virginia University,
written commun., 1992). Nitrogen-fertilizer sales estimates in this coverage
are reported for each county polygon in tons of actual nutrient sold (inorganic
nitrogen, phosphate, and potash) as distinct from total tons of fertilizer
product.

The data are summarized for fertilizer years (i.e. the 1987 fertilizer year
runs from July 1, 1986 to June 30, 1987).

The polygons representing county boundaries in the conterminous United States,
as well as lakes, estuaries, and other nonland-area features were derived from
the Digital Line Graph (DLG) file representing the 1:2,000,000-scale map in the
National Atlas of the United States (1970).