Inca Empire built on corn ... and poop

Photo by Alex Chepstow-Lusty

Llama excrement was used as a fertilizer for the maize that helped build the Inca Empire, including Machu Picchu shown here.

By John Roach

The seeds of the Inca Empire were planted about 2,700 years ago when a warm spell combined with piles of llama excrement allowed maize agriculture to take root high up in the South American Andes, according to a new study.

"They were constructing fields and weeding them. And probably trading took off, made possible by llama caravans transporting goods, such as maize, coca leaves, salt and a ceremonial product called cinnabar," Alex Chepstow-Lusty of the French Institute of Andean Studies in Lima told me Sunday in an email.

The finding is inferred by a record of pollen and mites in a core of mud taken from a small lake located at about 11,000 feet up in the Andes surrounded by agricultural terraces and next to an ancient trading route that connected tropical forest and mountain communities.

The Laguna Marcacocha core extends back over 4,200 years. The pollen tells Chepstow-Lusty about what plants were growing around the lake when. Mites eat plant detritus such as that found in excrement. "The more excrement, the more mites living in the soils close to the lake," he explained. Full article posted here