Feeding the Corn Belt: Intensification of Corn Cultivation in the U.S. Corn Belt, Resource Inputs, Impacts, and Implications Senior Thesis Presented to The Faculty of the School of Arts and Sciences Brandeis University Undergraduate Program in Environmental Studies, Advisor Dr. Dwight Peavey In partial fulfillment of the requirements for the Degree of Bachelor of Arts By: Hannah Moshay May 1st, 2018 1 Abstract The United States is currently the world’s largest producer, consumer, and exporter of corn. The concentrated cultivation of corn within the U.S. Corn Belt produces a third of the world’s corn. This intensive cultivation, has resulted from a number of resource inputs, namely land conversion, irrigation, and agrochemicals. The current corn management practices have been detrimental to the air, land, and water, and in turn resulted in increased nitrous oxide emissions, soil acidification, loss of carbon sequestration, and eutrophication. This thesis has two principle aims. Firstly, to compile and asses the historic and current practices of land use, water use, fertilizer use, and pesticide use within the U.S. Corn Belt. Secondly, to project global corn production to the year 2050 based on growing demand for livestock and ethanol, as well as the land, water, fertilizer, and pesticide input this will require. The following two facets of this thesis will be used to frame the argument that our current corn-dependent food systems and energy systems are fundamentally unsustainable, and have resulted in a “hungry-production system”. 2 Table of Contents Cover Page……………………………………………………………………………………pg. 1 Abstract………………………………………………………………………………………..pg. 2 Table of Contents………………………………………………………………………….....pg. 3 Tables and Figures…………………………………………………………………...………pg. 4-6 Introduction……………………………………………………………………………..……..pg. 7-10 Corn in U.S. Agriculture……………………………………………………………....……...pg. 10-23 The Corn Belt…………………………………………………………………………….…....pg. 23-26 Ecoregions and Hydrology of the Corn Belt……………………………………………….pg. 26-37 Land Use………………………………………………………………………………………pg. 37-53 Water Use……………………………………………………………………………………..pg. 53-64 Fertilizer Use………………………………………………………………………………….pg. 64-87 Pesticide Use……………………………………………………………………....…………pg. 87-122 Environmental Impact Summary……………………………………………………………pg. 123 Climate Change………………………………………………………………………………pg. 124-132 Demand……………………………………………………………………………………….pg. 133-143 Calculation……………………………………………………………………………………pg. 143-149 Conclusion……………………………………………………………………………………pg. 149-152 Acknowledgements…………………………………………………………………………pg. 152-153 Sources………………………………………………………………………………………pg. 154-163 3 Tables Table 1. U.S. Farm Sales Class Distribution………………………………………………..pg. 11 ​ ​ Table 2. U.S. Farm Sales Class and Farmland Operated………………………………...pg. 12 ​ ​ Table 3. Grain and Oilseed Operation Acreage…………...……………………………….pg. 13 ​ ​ Table 4. U.S. Planted Acreage of Field Crops…………………………….……………….pg. 13-14 ​ ​ Table 5. U.S. Production Total of Field Crops……………………………………………...pg. 14 ​ ​ Table 6. U.S. National Yield Average of Field Crops…………………………...………....pg. 15 ​ ​ Table 7. U.S. Commodity Prices of Field Crops…………………………...…………...….pg. 16 ​ ​ Table 8. Laingen’s Parameters………………………………………...…………………….pg. 24 ​ ​ Table 9. Laingen’s County Classification…………………………….…………………..…pg. 24-25 ​ ​ Table 10. State Acreage Granted Under the Swamp Lands Act...…………………...….pg. 38 ​ ​ ​ ​ Table 11. Total Subsurface Drainage Acreage and Percent Cropland with Subsurface Drainage ​ by State…………………………………………………………………………...…………....pg. 42 ​ Table 12. Historic Tallgrass, Mixed-grass, and Shortgrass Prairie Acreage……...…….pg. 45 ​ ​ Table 13. Cadmium Content of Phosphate Rocks…………………………...…………....pg. 83 ​ ​ Table 14. Claimed and Found Contents of NK Fertilizer Mix……………………………..pg. 84 ​ ​ Table 15. Claimed and Found Contents of Iron Amendment……………………………..pg. 84 ​ ​ Table 16. Claimed and Found Contents of Zinc and Zinc Sulfate………………………..pg. 85 ​ ​ Table 17. Glyphosate Resistant Weeds in the Corn Belt………………….…..………….pg. 101 ​ ​ Table 18. Atrazine Ecological Exposure Monitoring Program……………….…………...pg. 109 ​ ​ Table 19. Water Systems with Annual Averages above 3 ppb Atrazine………….……..pg. 117 ​ ​ Table 20. Water Systems with Highest Peak Atrazine Concentrations in Raw Water....pg. 118 ​ ​ Table 21. Water Systems with Highest Peak Atrazine Concentrations in Finished Water..pg. 119 ​ ​ Table 22. Bt-Crops, Cry Proteins and Target Pests………………………………………..pg. 122 ​ ​ Table 23. Summary of Intensive Agriculture Activities………………………………….....pg. 123 ​ ​ Table 24. Summary of Environmental Impacts of Intensive Agriculture Activities……...pg. 123 ​ ​ Table 25. Feed Conversion Ratio…………………………………………………………....pg. 135 ​ ​ Table 26. Projected Corn Production (bushels)..............................................................pg. 144 ​ ​ ​ ​ Table 27. Projected Corn Harvested Acreage (acres)..............................................pg. 144-145 ​ ​ Table 28. Corn Yield Projections (bu/ac)........................................................................pg. 145 ​ ​ Table 29. Corn Production, Acreage, and Yield Production for 2050…………….…..….pg. 145 ​ ​ Table 30. 2050 Water Requirements………………………………………………..……....pg. 146 ​ ​ Table 31. 2050 Fertilizer Use……………………………………………………..………….pg. 147 ​ ​ Table 32. 2050 Pesticides Use Prediction…………………………………..………..........pg. 148 ​ ​ Figures Figure 1. U.S. Corn Acreage 1866-2015……………………………………...……………pg. 21 ​ ​ 4 Figure 2. U.S. Total Corn Production 1866-2016……………………..……………….....pg. 22 ​ ​ Figure 3. U.S. Average Corn Yield 1866-2016……………………………………….......pg. 23 ​ ​ Figure 4. Map of the Corn Belt…………………………………………………………..….pg. 25 ​ ​ Figure 5. Corn Belt Ecoregions………………………………………………………….….pg. 27 ​ ​ Figure 6. United States River Basins……………………………………………..………..pg. 30 ​ ​ Figure 7. Upper Mississippi River Basin and Ohio Tennessee River Basin..………….pg. 31 ​ ​ Figure 8. Missouri River Basin……………………………………………..……………….pg. 32 ​ ​ Figure 9. United States Principal Aquifers…………………………..…………………….pg. 33 ​ ​ Figure 10. High Plains Aquifer…………………………………..………………………….pg. 36 ​ ​ Figure 11. Subsurface Drainage System……………………………………………..…...pg. 41 ​ ​ Figure 12. Subsurface Tile Drainage System Cover by County……………..………….pg. 42 ​ ​ Figure 13. Historic Boundaries of Tallgrass, Mixed-Grass, and Shortgrass Prairie…...pg. 44 ​ ​ Figure 14. U.S. Wind Speed Map…………………………………………………...……...pg. 47 ​ ​ Figure 15. Prairie dogs………………………………………………………...……………..pg. 48 ​ ​ Figure 16. Changes in CRP Enrollment by County…………………...…………………..pg. 51 ​ ​ Figure 17. Changes in Total CRP Enrollment Area……………...………………………..pg. 52 ​ ​ Figure 18. U.S. Water Withdrawals by Sector……………...……………………………...pg. 54 ​ ​ Figure 19. Irrigated Acreage Share by State………………………………………...…….pg. 56 ​ ​ Figure 20. Irrigated Acreage by Crop, Western and Eastern States…………………….pg. 57 ​ ​ Figure 21. Corn Yield Response to Irrigation……………………………………………....pg. 58 ​ ​ Figure 22. Nebraska and U.S. Irrigated versus Non-Irrigated Corn Yield……………….pg. 59 ​ ​ Figure 23. U.S. Drought 2012………………………………………………………………...pg. 60 ​ ​ Figure 24. Corn Water Use of Growing Season…………………………………………...pg. 61 ​ ​ Figure 25. U.S. Freshwater Withdrawals 2010…………………………………………….pg. 64 ​ ​ Figure 26. Synthetic Fertilizer Use by Four Major Crops 1964-2010…………………....pg. 66 ​ ​ Figure 27. U.S. Soil Nitrogen………………………………………………………………...pg. 67 ​ ​ Figure 28. Corn Nitrogen Use and Uptake…………………………………………...…….pg. 68 ​ ​ Figure 29. Seasonal Nitrogen Use…………………………………………………………..pg. 69 ​ ​ Figure 30. Fish Kill………………………………………………………………………...…..pg. 71 ​ ​ Figure 31. Nitrogen Loading from Corn Belt………………………………………………..pg. 72 ​ ​ Figure 32. Hypoxia in the Gulf of Mexico Dead Zone……………………………………..pg. 73 ​ ​ Figure 33. Nitrogen Inputs by County within Mississippi River Basin………..………....pg. 74 ​ ​ Figure 34. Tile Drainage Concentration by County in Mississippi River Basin…….…...pg. 75 ​ ​ Figure 35. Predicted Nitrogen Loading of Mississippi River Basin by County………….pg. 76 ​ ​ Figure 36. Groundwater Nitrate Contamination Risk……………………………………...pg. 77 ​ ​ Figure 37. Nebraska Groundwater Nitrate Contamination……………………………….pg. 78-79 ​ ​ Figure 38. Cadmium Concentrations in Grains with Manipulations of Soil pH and Soil ​ Cadmium……………………………………………………………………………………….pg. 86-87 ​ Figure 39. U.S. Annual Pesticide Use……………………………………………….……..pg. 88 ​ ​ Figure 40. Pesticide Use By Crop……………………………………………………...…...pg. 89 ​ ​ Figure 41. Corn Acreage Treated with Pesticides…………………………………….......pg. 90 ​ ​ Figure 42. Glyphosate Structure…………………………………………………....……….pg. 91 ​ ​ Figure 43. Glyphosate Use by Crop……………………………………………….………..pg. 92 ​ ​ 5 Figure 44. Estimated Agriculture Use of Glyphosate 1992, Low Use Estimate……....pg. 93 ​ ​ Figure 45. Estimated Agriculture Use of Glyphosate 1992, High Use Estimate……...pg. 94 ​ ​ Figure 46. Herbicide Acreage in Relation to HT Corn Acreage………………………...pg. 95 ​ ​ Figure 47. Estimated Agricultural Use for Glyphosate 2015, Low Use Estimate……..pg. 96 ​ ​ Figure 48. Estimated Agricultural Use for Glyphosate 2015, High Use Estimate….....pg. 97 ​ ​ Figure 49. Collembola………………………………………………………………..……...pg. 100 ​ ​ Figure 50. Oniscidea………………………………………………………………………...pg. 100 ​ ​ Figure 51. Glyphosate Resistant Species by State……………………………………....pg. 101 ​ ​ Figure 52. Glyphosate Resistance in Populations………………………………...……..pg. 103 ​ ​ Figure 53. Atrazine Structure……………………………………………………………….pg. 104 ​ ​ Figure 54. Atrazine Use by Crop…………………………………………………………...pg. 105 ​ ​ Figure 55. Estimated Agricultural