National Geographic Creative/Alamy Stock Photo Bird poop brings 3.8 million metric tons of nitrogen out of the sea each year By Sid PerkinsJan. 23, 2018 , 11:00 AM Long before the rise of modern agriculture, humans relied on three things to bring nitrogen to barren soils: lightning strikes, nitrogen-fixing bacteria, and natural fertilizers. Among those, theContinue reading “Bird poop brings 3.8 million metric tons of nitrogen out of the sea each year”