Just precisely what does all of that nitrogen fertilizer do to the soil? “Fertilizer is good for the father and bad for the sons.” –Dutch saying

For all of its ecological baggage, synthetic nitrogen does one good deed for the environment: it helps build carbon in soil. At least, that’s what scientists have assumed for decades.

If that were true, it would count as a major environmental benefit of synthetic N use. At a time of climate chaos and ever-growing global greenhouse gas emissions, anything that helps vast swaths of farmland sponge up carbon would be a stabilizing force. Moreover, carbon-rich soils store nutrients and have the potential to remain fertile over time–a boon for future generations.