A Brief History of Our Deadly Addiction to Nitrogen Fertilizer

As investigators and rescuers move through a destroyed fertilizer factory in West, Texas, it makes me think about just what nitrogen fertilizer is, and why we use so much of it.

Nitrogen is one of the nutrient elements plants need to grow. Every apple or ear of corn plucked represents nutrients pulled from soil, and for land to remain productive, those nutrients must be replenished. Nitrogen is extremely plentiful—it makes up nearly 80 percent of the air we breathe. But atmospheric nitrogen (N2) is joined together in an extremely tight bond that makes it unusable by plants. Plant-available nitrogen, known as nitrate, is actually scarce, and for most of agriculture's 10,000-year-old history, the main challenge was figuring out how to cycle usable nitrogen back into the soil. Farmers of yore might not have known the chemistry, but they knew that composting crop waste, animal manure, and even human waste led to better harvests.