Pigeon Towers: A Low-tech Alternative to Synthetic Fertilizers

Pigeon Towers: A Low-tech Alternative to Synthetic Fertilizers

Many societies, ancient and contemporary, have innovated ways of supplying their fields with fixed nitrogen and phosphorus—two crucial ingredients for crop productivity. One is crop rotation, which alternates nitrogen-fixing and nitrogen-exhausting crops. Farmers around the world make use of chickens, ducks, and geese to add