The importance of agriculture led the indigenous people to look for fertilizers for their crops. The information we possess about fertilizer comes from the coast and shows the use made of renewable natural resources

The main fertilizers used are named by the chronicler and were used especially for maize production which confirms Murra's suggestion regarding the priority of this crop.

A first fertilizer consisted of burying small fish like sardines or anchovies together with the kernels. A representation of this system was painted on the walls of one of the sanctuaries of Pachacamac where a maize plant was figured germinating from some little fish. The second fertilizer used was the dung of marine birds which nested by the thousands on the offshore islands. The resource called guano was formed by the dejections of the birds and it was the custom of the coastal people to extract guano from the islands. The third renewable resource came from the humus from fallen leaves of the carob and guarango trees used to improve soils.