Gail P. Thelin and Wesley W. Stone 2010 Version 1.1, November 13 2009 tabular digital data Sacramento, CA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?sir2010-5034 Gail P. Thelin and Wesley W. Stone 2010 SIR 2010--5034 document U.S. Geological Survey Scientific Investigations Report USGS SIR 2010-5034 Sacramento, California U.S. Geological Survey http://pubs.usgs.gov/sir/2010/5034/ This data set contains annual county-level estimates of total atrazine use on 16 agricultural crops and four agricultural land uses between 1992 and 2007. For each year, atrazine use was estimated for all counties in the conterminous U.S. (except California) by combining (1) proprietary data from the DMRKynetec (DMRK) AgroTrak database on the mass of atrazine applied annually to agricultural crops, (2) county harvested crop acreage, from the 1992, 1997, 2002, and 2007 U.S. Department of Agriculture (USDA) Censuses of Agriculture, and (3) annual harvested crop acreage from the National Agriculture Statistics Service (NASS) for non-Census years between 1992 and 2007. Annual DMRK estimates of pesticide use on individual crops were derived from surveys of major field crops and selected specialty crops in multicounty areas referred to as Crop Reporting Districts (CRD). The CRD-level atrazine-use estimates were disaggregated to obtain county-level application rates by dividing the mass (pounds) of pesticides applied to a crop by the acreage of that crop in the CRD, to yield a rate per harvested acre. When atrazine-use estimates were not available for a CRD, crop, or year, an estimated CRD-level rate was developed following a hierarchy of decision rules that checked first for the availability of a crop application rate from surveyed atrazine application rate(s) for adjacent CRDs for a specific year, and second, the rates from surveyed CRDs within for USDA Farm Production Regions for a specific year or multiple years. The estimation method applied linear interpolation to estimate crop acreage for years when harvested acres for a crop and county were not reported in either the Census of Agriculture or the NASS database, but were reported by these data sources for other years for that crop and county. Data on atrazine use for the counties in California were obtained from farmers' reports of pesticide use collected and published by the California Department of Pesticide Regulation-Pesticide Use Reporting (DPR-PUR) because these data are more complete than DMRK survey data. National and state annual atrazine-use totals derived by this method were compared with other published pesticide-use estimates and were highly correlated. The method developed is designed to be applicable to other pesticides for which there are similar data; however, for some pesticides that are applied to specialty crops, fewer surveys are usually available to estimate application rates and there are a greater number of years with unreported crop acreage, potentially resulting in greater uncertainty in use estimates. These data are appropriate for making annual assessments of atrazine use for the Nation, states or multi-county areas. 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 publication date Complete None planned -127.977 -65.118 48.283 23.0933 none inlandWaters agricultural pesticide use atrazine herbicides crop management corn herbicides none Conterminous U.S. counties of the conterminous U.S. none 1992-2007 none These data are appropriate for estimating atrazine use at national and regional scales, and for multi-county areas. County estimates are available for counties that have crop acreage reported by the USDA Census of Agriculture or NASS Agricultural Statistics database. County atrazine use may be under estimated for some counties that did not publish crop acreage because of USDA nondisclosure rules. In some cases, the county atrazine use estimate may have been calculated using a derived application rate from a neighboring Crop Reporting District (CRD) or from a rate developed from the rates of CRDs within one of the 10 USDA Farm Production Regions for a specific year or multiple years. U.S. Geological Survey Gail P. Thelen mailing address

Placer Hall, 6000 J Street

Sacramento CA 95819-6129 Sacramento 916-278-3095 gpthelin@usgs.gov http://water.usgs.gov/GIS/browse/atrazine.jpg Map of atrazine data set created by a county relate JPG Gail P. Thelin and Wesley W. Stone Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.1850 Please refer to SIR 2010-5034 which describes comparisons that were made with NASS Chemical Use data for selected states, crops, and years. current at time of release USDA 2009 tabular digital data The Census of Agriculture Volume 1, Chapter 2: County Level Data Washington, D.C. U.S. Department of Agriculture See USGS SIR 2010-5034, Table 2. for a list of crops used. http://www.agcensus.usda.gov/ online 2007 2002 1997 1992 current at time of release USDA Census of Agriculture Census of Agriculture county harvested crop acreage was used to calculate crop application rates and estimate atrazine use for 1992, 1997, 2002, and 2007. USDA 2009 tabular digital data Washington, D.C. USDA See USGS SIR 2010-5034, Table 2 for a list of crops used. http://www.nass.usda.gov/Data_and_Statistics/Quick_Stats/index.asp online 1993 1994 1995 1996 1998 1999 2000 2001 2003 2004 2005 2006 current at time of release USDA National Agricultural Statistics Service NASS county harvested crop acreage was used to calculate crop application rates and estimate atrazine use for the years 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2003, 2004, 2005, and 2006. California Department of Pesticide Regulation (DPR) 2009 tabular digital data Sacramento, CA California Department of Pesticide Regulation http://www.cdpr.ca.gov/docs/pur/purmain.htm online 1992 2007 current at time of release DPR-PUR California DPR 1992-2007 annual use reports were used to estimate atrazine for California counties. refer to SIR 2010-5034 2010 county FIPS code FIPS: 5-digit unique code representing a state (first two digits) and county (last three digits) County: alpha name corresponding to the county FIPS code CMPND: compound name. YR: year of the estimate. Valid dates are from 1992 to 2007. LBS: estimated pounds of the compound applied to agricultural crops grown within the county for a specific year none U.S. Geological Survey Ask USGS - Water Webserver Team mailing address

445 National Center

Reston Virginia 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+sir2010-5034 Downloadable Data Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data, software, or related materials. The use of firm, trade, or brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. The names mentioned in this document may be trademarks or registered trademarks of their respective trademark owners. These are comma-delimited text files. Winzip 4.048 http://water.usgs.gov/GIS/dsdl/atrazine_1992_2007.zip None. This dataset is provided by USGS as a public service. 20100811 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

445 National Center

Reston VA 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://water.usgs.gov/user_feedback_form.html 6 FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998