Big Ag is addicted to nitrogen fertilizers. It’s a massive problem for the global climate, yet it may yield to a microscopic solution: microbes rewired to “fix” nitrogen from the air and turn it into a natural type of fertilizer that corn, wheat, and other cereal crops can use.
Until the Green Revolution changed agriculture in the mid-20th century, farmers fed cereal crops either by spreading nitrogen-rich manure on their fields or by planting a legume crop (such as beans or peas) whose root systems contain microbes that naturally nab atmospheric nitrogen, and then plowing that crop under to fertilize the cereal crop they actually wanted to grow. But these inefficient methods couldn’t begin to support the 7 billion people alive today. The Green Revolution ushered in a new era of chemical fertilizers, enabling farmers to feed the booming global population—but also creating a dangerous addiction.