Annual county-level pesticide use was estimated for 423 herbicides, insecticides, and fungicides applied to agricultural crops grown in the conterminous United States during 2008–12. For all States except California, pesticide-use data were compiled from proprietary surveys of farm operations located within U.S. Department of Agriculture Crop Reporting Districts (CRDs). Surveyed pesticide-use data were used in conjunction with county annual harvested-crop acres reported by the U.S. Department of Agriculture 2007 and 2012 Censuses of Agriculture and the 2008–11 County Agricultural Production Survey to calculate use rates per harvested-crop acre, or an “estimated pesticide use” (EPest) rate, for each crop by year. County-use estimates were then calculated by multiplying EPest rates by harvested-crop acres for each pesticide crop combination. Use estimates for California were obtained from annual Department of Pesticide Regulation-Pesticide Use Reports.

Proprietary surveyed pesticide-use data were not available for all CRDs and years. When pesticide-survey data were unavailable for a CRD in a particular year, EPest extrapolated rates were calculated from adjoining or nearby CRDs to ensure that pesticide use was estimated for all counties where harvested-crop acres were reported. Two estimation methods were used—EPest-low and EPest high—and differed in how they treated situations when a CRD was surveyed and pesticide use was not reported for a particular pesticide-by-crop combination. California pesticide-use estimates were not extrapolated; therefore, EPest-low and EPest-high are the same for counties in California.

This data series is a continuation of the 1992–2009 pesticide-use estimates reported by Stone (2013). It is an update of estimates for 2008–9 (Stone, 2013), as well as an update of the 2010–11 preliminary estimates reported by Baker and Stone (2013). EPest values from these compilations (1992–2012) are suitable for making national, regional, and watershed assessments of annual pesticide use. County-level estimates are provided to make it easier to compile watershed assessments; however, users should be aware there is a greater degree of uncertainty in individual county-level estimates when compared to CRD or State-level estimates. This report provides EPest-low and EPest-high annual agricultural pesticide use for counties of the conterminous United States for 423 compounds during 2008–12 in tab-delimited files organized by compound, year, State Federal Information Processing Standard (FIPS) code, county FIPS code, and amount in kilograms (kg).

EPest-high county pesticide-use estimates were divided into tables 1 through 7 by pesticide name:

Table 1: 2, 4-D through Chlorantraniliprole
Table 2: Chlorethoxyfos through Diflufenzopyr 
Table 3: Dimethenamid through Gibberellic acid 
Table 4: Glufosinate through Metiram 
Table 5: Metolachlor through Propazine 
Table 6: Propiconazole through Triasulfuron 
Table 7: Tribenuron methyl through Zoxamide

EPest-low county pesticide-use estimates were divided into tables 8 through 14 by pesticide name:

Table 8: 2, 4-D through Chlorantraniliprole 
Table 9: Chlorethoxyfos through Diflufenzopyr 
Table 10: Dimethenamid through Gibberellic acid 
Table 11: Glufosinate through Metiram 
Table 12: Metolachlor through Propazine 
Table 13: Propiconazole through Triasulfuron 
Table 14: Tribenuron methyl through Zoxamide