Our Fertilized World: A Mixed Blessing

If we don’t watch out, agriculture could destroy our planet. Here’s how to grow all the food we need with fewer chemicals.

By Dan Charles
National Geographic

N. Nitrogen. Atomic number seven. Unnoticed, untasted, it nevertheless fills our stomachs. It is the engine of agriculture, the key to plenty in our crowded, hungry world.

Without this independent-minded element, disinclined to associate with other gases, the machinery of photosynthesis cannot function—no protein can form, and no plant can grow. Corn, wheat, and rice, the fast-growing crops on which humanity depends for survival, are among the most nitrogen hungry of all plants. They demand more, in fact, than nature alone can provide.

Enter modern chemistry. Giant factories capture inert nitrogen gas from the vast stores in our atmosphere and force it into a chemical union with the hydrogen in natural gas, creating the reactive compounds that plants crave. That nitrogen fertilizer—more than a hundred million tons applied worldwide every year—fuels bountiful harvests. Without it, human civilization in its current form could not exist. Our planet’s soil simply could not grow enough food to provide all seven billion of us our accustomed diet. In fact, almost half of the nitrogen found in our bodies’ muscle and organ tissue started out in a fertilizer factory.

Yet this modern miracle exacts a price. Runaway nitrogen is suffocating wildlife in lakes and estuaries, contaminating groundwater, and even warming the globe’s climate. As a hungry world looks ahead to billions more mouths needing nitrogen-rich protein, how much clean water and air will survive our demand for fertile fields?

(More here.)