The Aztecs built an agricultural system in the 14th century that produced seven harvests a year without synthetic fertiliser, irrigation pipes, or chemical inputs, fed a city of 200,000 people for two centuries, was destroyed by Spanish conquest in 1521, and is now being painstakingly rebuilt by farmers and scientists in the only part of it that survived.

The Valley of Mexico sits at an altitude of approximately 2,240 metres in a basin that, in the early fourteenth century, was largely covered by an interconnected system of shallow freshwater lakes. The Aztecs arrived in the basin as outsiders. Every fertile shoreline was already claimed by older settled peoples. What the Aztecs had available [...] The post The Aztecs built an agricultural system in the 14th century that produced seven harvests a year without synthetic fertiliser, irrigation pipe