In Inca times all tribes were on about the same technological level in their agriculture. Work was communal, and the most
important implement was the taclla, a simple digging stick consisting of a pole with a thick fire-hardened point.
Arable land was not unlimited. Rain generally falls in the Andes between December and May, but there are often years of
drought. Water had to be brought to arable lands by canals, many of which showed superb engineering techniques. Terracing
of the land to prevent erosion was begun by the pre-Inca tribes and elaborated under the Incas.
Andean agriculture was sedentary; the slash-and-burn techniques practiced by the Mexican Indians and the Mayas, in which
virgin forest land was constantly being cleared and planted, were not normally employed by the Andean peoples. The Middle
American cultures had no natural fertilizer except decayed fish and human feces, whereas in Peru the coastal farmer had guano
and the Andean farmer had taqui, the offal of the llama.