Earth Watch: Lost in the Maize, The Silent Toll of America’s Number One Crop

It's grilling season, and there's one crop that dominates the menu, even when we're not serving it on the cob. Burgers and brats, salad dressing and barbecue sauce, sodas, and alcoholic beverages, they all have this in common: corn.1 2


Earth Watch: Lost in the Maize, The Silent Toll of America’s Number One Crop


Corn makes up 95 percent of the total feed grain used in dairy, beef, poultry, and pork production and it's an ingredient in countless processed foods, in the form of high-fructose corn syrup, corn starch, corn oil, and even citric acid (there are approximately 90 food additives that are derived from corn; so if you eat something that comes in a bag or box, chances are, you’re eating something that was made from corn). With more than 90 million acres planted, it’s the number one crop grown in the U.S., and more than 90 percent of it relies on GMO herbicide-tolerant and/or insect-resistant seeds.3 4 It is also a crop that relies heavily on chemical fertilizers.

The status quo

After World War II, U.S. factories had an excess of ammonium nitrate used to make explosives, and as it happens, it was also good at adding nitrogen—required by plants to grow—to the soil. So chemical fertilizer was introduced to agriculture, and at the front of the line were high-yield cultivars of corn. Marrying the two meant yields exploded, and the Corn Belt has never looked back. 5 6 Now, the region must look forward, to a future where one of its most valuable resources, the soil, is increasingly degraded.

The long-term loss of soil fertility in conventional industrial farming systems can be hard to measure, obscured by the constant chemical input of nutrients. Researchers from the University of Colorado addressed this question in a recent study and determined that 30 percent of the fertilizer currently applied to farmland is just to compensate for long-term losses in soil fertility due to erosion and loss of soil organic matter, a result of industrial farming methods that rely on chemical inputs, like synthetic fertilizers, and monocropping. The price tag for the fertilizer required to compensate for lost soil fertility is about half a billion dollars per year, and that's not including the environmental costs that synthetic fertilizer incurs.7 8 

Count the cost

Consider a sampling of the externalized costs of synthetic fertilizer to the environment and human health:

  • Nitrogen fertilizer is a significant source of nitrous oxide (N2O) emissions, a greenhouse gas with almost 300 times the warming potential of carbon dioxide and the primary (human caused) destroyer of stratospheric ozone. 9 10 11 According to a 2015 study in Minnesota, N2O emissions in the Corn Belt may be underestimated by 40 percent because it does not account for emissions from streams that contain fertilizer runoff. 12
  • Agricultural nutrient runoff (nitrogen and phosphorous) in the Mississippi River is a primary contributor to the annually occurring hypoxic dead zone in the Gulf of Mexico. The loss to seafood and tourism industries is roughly $82 million each year. 13 14
  • According to a study published in Nature Sustainability, corn production is a major source of deadly air pollution, in the form of fine particulate matter, resulting in 4,300 premature deaths each year. Ammonia from fertilizer application was the largest contributor and was calculated to be responsible for seventy percent of attributable deaths.15 16

Regenerative organic agriculture tells a different story

There are approaches to farming that restore soil fertility, improve water holding capacity, decrease emissions, and sequester carbon.8 Crop diversity, nitrogen-fixing cover crops, and compost are all essential components of organic farming—and counterparts to industrial agriculture’s most destructive practices.17 18 Managed, rotational grazing of livestock plays a pivotal role in restoring degraded lands and increasing carbon sequestration through factors including recycling plant materials, naturally fertilizing the soil, depositing organic matter, and reducing nutrient losses from the soil.19 20 21

Pasture-based dairy, 100% grass-fed, and 100 percent organic produce—these are food choices that represent increased value to farmers, the environment, animal welfare, and human health. So as you shop for your next summer feast, what’s your grocery bill going to reflect? Will it be the values you believe in today or the hidden price the next generation will pay tomorrow?


  1. “The Oxford Companion to Beer Definition of Corn.” Craft Beer & Brewing,
  2. “Factbox: Corn Plant and Products Made from Corn.” Reuters, Thomson Reuters, 29 Sept. 2010,….
  3. “Feedgrains Sector at a Glance.” USDA ERS - Feedgrains Sector at a Glance,….
  4. “Recent Trends in GE Adoption.” USDA ERS - Recent Trends in GE Adoption,….
  5. “What's Eating America.”, Smithsonian Institution, 1 July 2006,
  6. Philpott, Tom. “A Brief History of Our Deadly Addiction to Nitrogen Fertilizer.” Mother Jones, 19 Apr. 2013,
  7. Jang, W. S., et al. “The Hidden Costs of Land Degradation in US Maize Agriculture.” AGU Journals, John Wiley & Sons, Ltd, 12 Feb. 2021,
  8. Strickler, Jordan. “Soil Loss Costs U.S. Corn Farmers Half a Billion Dollars Each Year.” Forbes, Forbes Magazine, 27 Jan. 2021,….
  9. “Overview of Greenhouse Gases.” EPA, Environmental Protection Agency, 14 Apr. 2021,
  10. “Understanding Global Warming Potentials.” EPA, Environmental Protection Agency, 9 Sept. 2020,
  11. “Nitrous Oxide Now Top Ozone-Depleting Emission.” ScienceDaily, ScienceDaily, 28 Aug. 2009,
  12. Turner, Peter A., et al. “Indirect Nitrous Oxide Emissions from Streams within the US Corn Belt Scale with Stream Order.” PNAS, National Academy of Sciences, 11 Aug. 2015,
  13. “Gulf of Mexico Dead Zone.” The Nature Conservancy,….
  14. “What Is the Gulf of Mexico Dead Zone?” Restore the Mississippi River Delta, 3 Oct. 2019,
  15. Lambert, Jonathan. “Growing Corn Is A Major Contributor To Air Pollution, Study Finds.” NPR, NPR, 1 Apr. 2019,….
  16. Hill, Jason, et al. “Air-Quality-Related Health Damages of Maize.” Https://, May 2019,
  17. Scialabba, Nadia El-Hage, and Maria Müller-Lindenlauf. “Organic Agriculture and Climate Change: Renewable Agriculture and Food Systems.” Cambridge Core, Cambridge University Press, 30 Mar. 2010,….
  18. “Organic vs Conventional.” Rodale Institute, 3 Dec. 2018,
  19. “Pasture Project : Grazing Benefits.” The Pasture Project,
  20. Nargi, Lela. “Can Cows Help Mitigate Climate Change? Yes, They Can!” Https://,
  21. “Integrated Crop / Livestock Systems.” Community Alliance with Family Farmers, 12 Nov. 2020,….