References

¹ U.S. Department of Agriculture. 2009. Summary Report: 2007 National Resources Inventory. Natural Resources Conservation Service, Washington, DC and Center for Survey Statistics and Methodology, Iowa State University, Ames, Iowa. 123 pages. http://www.nrcs.usda.gov/technical/NRI/2007/2007_NRI_Summary.pdf

² Iowa State University, National Soil Erosion Research Lab, National Laboratory for Agriculture and the Environment and the University of Iowa. Iowa Daily Erosion Project. http://wepp.mesonet.agron.iastate.edu/

³ The Public Land Survey System. Nationalatlas.gov. http://www.nationalatlas.gov/articles/boundaries/a_plss.html

⁴ Iowa Geological Survey, Geographic Information Systems Section. Land Cover for the State of Iowa in the Year 2002. http://www.igsb.uiowa.edu/webapps/nrgislibx/

⁵ Conservation Technology Information Center. National Crop Residue Management Survey. http://www.ctic.purdue.edu/CRM/

⁶ Takle, E. S., and S. C. Pryor, 2008: Where is climate science in the Midwest going? Chapter 24. In S. C. Pryor, ed., Understanding Climate Change: Climate Variability, Predictability and Change in the Midwestern United States. Indiana University Press. 312 pp.

⁷ Gordon, L.M., S.J. Bennett, C.V. Alonso, and R.L. Binger. 2008. Modeling long-term soil losses on agricultural fields due to ephemeral gully erosion. Journal of Soil and Water Conservation 63(4):173-181.

⁸ U.S. Department of Agriculture, Natural Resources Conservation Service. 1997. America’s Private Land: A Geography of Hope. United States Department of Agriculture–Natural Resources Conservation Service, Washington, DC, p. 39. http://www.nrcs.usda.gov/news/pub/GHopeHit.html

⁹ Iowa Environmental Mesonet, Iowa State University Department of Agronomy. http://mesonet.agron.iastate.edu/

¹⁰ USDA Natural Resources Conservation Service. 1998. Erosion and Sediment Delivery. Iowa Natural Resources Conservation Service Electronic Field Office Technical Guide. http://efotg.sc.egov.usda.gov//references/public/IA/Erosion_and_sediment_delivery.pdf

¹¹ Gordon, L.M., S.J. Bennett, C.V. Alonso, and R.L. Binger. 2008. Modeling long-term soil losses on agricultural fields due to ephemeral gully erosion. Journal of Soil and Water Conservation 63(4):173-181.

¹² U.S. Environmental Protection Agency. Watershed Assessment, Tracking & Environmental Results. National Probable Sources Contribution to Impairments. http://iaspub.epa.gov/waters10/attains_nation_cy.control – prob_source

¹³ Heffernan, A., T. Galluzzo and W. Hoyer. 2010. Solution to Pollution: It Starts on the Farm. The Iowa Policy Project, Iowa City, Iowa. September 2010. http://www.iowapolicyproject.org/2010docs/100927-nutrients.pdf

¹⁴ U.S. Department of Agriculture, National Agricultural Statistics Service. 2006. Agricultural Chemical Usage 2005 Field Crops Summary. AgCH 1(06)

¹⁵ Estimate derived from livestock numbers for Iowa in the 2007 Census of Agriculture and manure production factors used by the Iowa Department of Natural Resources.

¹⁶ Science-based Trials of Rowcrops Integrated with Prairie (STRIPs) Project. Iowa State University. http://www.nrem.iastate.edu/research/STRIPs/news/docs/field day handout neal smith 09.pdf

¹⁷ Heartland Regional Water Coordination Initiative. Agricultural Phosphorus Management and Water Quality Protection in the Midwest. University of Nebraska http://www.ianrpubs.unl.edu/epublic/live/rp187/build/rp187.pdf

¹⁸ Heartland Regional Water Coordination Initiative. 2006. Agricultural Nitrogen Management for Water Quality Protection in the Midwest. University of Nebraska. http://www.ksre.ksu.edu/waterquality/nitrogen pub.pdf

¹⁹ Iowa Department of Natural Resources, Beach Monitoring: http://www.igsb.uiowa.edu/wqm/activities/beach/FAQ.htm

²⁰ Tomer. M.D., C.G. Wilson, T.B. Moorman, K.J. Cole, D. Heer and T.M. Isenhart. 2010. Source-Pathway Separation of Multiple Contaminants during a Rainfall-Runoff Event in an Artificially Drained Agricultural Watershed. Journal of Environmental Quality 39:882-895.

²¹ Iowa Department of Natural Resources, Watershed Monitoring and Assessment. Water Quality Index. http://www.igsb.uiowa.edu/wqm/wqi/wqi.asp

²² State-EPA Nutrient Innovations Task Group. 2009. An Urgent Call to Action. http://water.epa.gov/scitech/swguidance/waterquality/standards/criteria/aqlife/pollutants/nutrient/
upload/2009_08_27_criteria_nutrient_nitgreport.pdf

²³ State-EPA Nutrient Innovations Task Group. 2009. An Urgent Call to Action. http://water.epa.gov/scitech/swguidance/waterquality/standards/criteria/aqlife/pollutants/nutrient/
upload/2009_08_27_criteria_nutrient_nitgreport.pdf

²⁴ U.S. Environmental Protection Agency. Watershed Assessment, Tracking & Environmental Results. National Probable Sources Contribution to Impairments. http://iaspub.epa.gov/waters10/attains_nation_cy.control – prob_source

²⁵ U.S. Environmental Protection Agency. Watershed Assessment, Tracking & Environmental Results. National Probable Sources Contribution to Impairments. http://iaspub.epa.gov/waters10/attains_nation_cy.control – prob_source

²⁶ U.S. Environmental Protection Agency. Watershed Assessment, Tracking & Environmental Results. National Probable Sources Contribution to Impairments. http://iaspub.epa.gov/waters10/attains_nation_cy.control – prob_source

²⁷ U.S. Environmental Protection Agency. Watershed Assessment, Tracking & Environmental Results. National Probable Sources Contribution to Impairments. http://iaspub.epa.gov/waters10/attains_nation_cy.control – prob_source

²⁸ Committee on Environment and Natural Resources. 2010. Scientific Assessment of Hypoxia in U.S. Coastal Waters. Interagency Working Group on Harmful Algal Blooms, Hypoxia, and Human Health of the Joint Subcommittee on Ocean Science and Technology, Washington, DC. http://www.whitehouse.gov/sites/default/files/microsites/ostp/hypoxia-report.pdf

²⁹ Mississippi River/Gulf of Mexico Watershed Nutrient Task Force. 2008. Gulf Hypoxia Action Plan. http://water.epa.gov/type/watersheds/named/msbasin/actionplan.cfm

³⁰ Rabelais, N. and R.E. Turner. 2010. 2010 Dead Zone—One of the Largest Ever. http://www.gulfhypoxia.net/Research/Shelfwide Cruises/2010/PressRelease2010.pdf

³¹ Johnson, L.C. 1987. Soil loss tolerance: Fact or myth? Journal of Soil and Water Conservation 42(3):155-160.

³² Logan, T. 1982. Improved criteria for developing soil loss tolerance levels for cropland. In Determinants of Soil Loss Tolerance. Special Publication No. 45. American Society of Agronomy, Madison, Wisconsin.

³³ Helmers, M.J., T.M. Isenhart, M.G. Dosskey, S.M. Dabney, and J.S. Strock. 2008. Buffers and Vegetative Filter Strips. Chapter 4 in Upper Mississippi River Sub-basin Hypoxia Nutrient Committee Final Report: Gulf Hypoxia and Local Water Quality Concerns Workshop. American Society of Agricultural and Biological Engineers, St. Joseph, Michigan.

³⁴ Science-based Trials of Rowcrops Integrated with Prairie (STRIPs) Project. Iowa State University. http://www.nrem.iastate.edu/research/STRIPs/news/docs/field day handout neal smith 09.pdf

³⁵ Baldwin, J. 2008. ‘Worst natural disaster in state history.’ Iowa.com http://iowa.com/ilive/flood-of-2008/

³⁶ Sekely, A.C., D.J. Mulla, and D.W. Bauer. 2002. Streambank slumping and its contribution to the phosphorus and suspended sediment loads of the Blue Earth River, Minnesota. Journal of Soil and Water Conservation 57(5):243-250.

³⁷ Schilling, K.E. and C.F. Wolter. 2000. Application of GPS and GIS to map channel features in Walnut Creek, Iowa. Journal of the American Water Resources Association: 36(6):1423-1434.

³⁸ Wilson, C.G., D.D. Bosch, J.L. Steiner, P.J. Starks, M.D. Tomer, and G.V. Wilson. 2008. Quantifying relative contributions from sediment sources in Conservation Effects Assessment Project watersheds. Journal of Soil and Water Conservation 63(6):523-532.

³⁹ Lowrance, R., T.M. Isenhart, W.J. Gburek, F.D. Shields, Jr., P.J. Wigington, and S.M. Dabney. 2006. Landscape Management Practices. Chapter 7 in M. Schnepf and C. Cox (eds) Environmental Benefits of Cropland Conservation: The Status of Our Knowledge. Soil and Water Conservation Society, Ankeny, Iowa. 269-317.

⁴⁰ Reeder R. and D. Westermann. 2006. Soil Management Practices. Chapter 1 in M. Schnepf and C. Cox (eds) Environmental Benefits of Cropland Conservation: The Status of Our Knowledge. Soil and Water Conservation Society, Ankeny, Iowa. 1-89.

⁴¹ Tomer. M.D., C.G. Wilson, T.B. Moorman, K.J. Cole, D. Heer and T.M. Isenhart. 2010. Source-Pathway Separation of Multiple Contaminants during a Rainfall-Runoff Event in an Artificially Drained Agricultural Watershed. Journal of Environmental Quality 39:882-895.

⁴² Helmers, M.J., T.M. Isenhart, M.G. Dosskey, S.M. Dabney, and J.S. Strock. 2008. Buffers and Vegetative Filter Strips. Chapter 4 in Upper Mississippi River Sub-basin Hypoxia Nutrient Committee Final Report: Gulf Hypoxia and Local Water Quality Concerns Workshop. American Society of Agricultural and Biological Engineers, St. Joseph, Michigan.

⁴³ Randall, G.W. and M.J. Goss. 2008. Nitrate Losses to Surface Water Through Subsurface, Tile Drainage. Chapter 6 in J.L. Hatfield and R.F Follett (Eds) Nitrogen in the Environment: Sources, Problems, and Management, pps 145-174. Elsevier, Inc. http://www.sciencedirect.com/science/book/9780123743473

⁴⁴ Claassen, R., V. Breneman, S. Bucholtz, A. Cattaneo, R. Johansson, and M. Morehart. 2004. Environmental Compliance in U.S. Agricultural Policy: Past Performance and Future Potential. Agricultural Economic Report No. 832. U.S. Department of Agriculture, Economic Research Service, June 2004. http://www.ers.usda.gov/Publications/AER832/

⁴⁵ Environmental Working Group. Farm Subsidy Database. https://farm.ewg.org/index.php?key=nosign

⁴⁶ Derived from data on ethanol production from the Renewable Fuels Association (RFA).

⁴⁷ Duffy, M. 2010. Farmland ownership: What are the implications for conservation, the next generation? Summer 2010 Leopold Letter. Leopold Center for Sustainable Agriculture, Iowa State University. http://leopold.iastate.edu/pubs/nwl/2010/2010-2-leoletter

⁴⁸ Iowa Farm and Rural Life Poll. 2010. Rented Land In Iowa: Social and Environmental Dimensions. Iowa State University Extension, PMR 1006, January 2010. http://www.soc.iastate.edu/extension/farmpoll/PMR1006.pdf

⁴⁹ DeGennaro, D. 2010. Farm Income Data Debunks Subsidy Myths. Environmental Working Group. https://www.ewg.org/agmag/2010/05/farm-income-data-debunks-subsidy-myths/

⁵⁰ DeGennaro, D. 2010. Farm Income Data Debunks Subsidy Myths. Environmental Working Group. https://www.ewg.org/agmag/2010/05/farm-income-data-debunks-subsidy-myths/

⁵¹ Environmental Working Group. Farm Subsidy Database. https://farm.ewg.org/index.php?key=nosign

⁵² Environmental Working Group. Farm Subsidy Database. https://farm.ewg.org/index.php?key=nosign

⁵³ Cox, C. and N. Bruzelius. 2010. The Other National Debt. Environmental Working Group. https://www.ewg.org/agmag/2010/03/the-other-national-debt/

⁵⁴ Derived from data presented in U.S. Department of Agriculture, Natural Resources Conservation Service annual budget documents.