It is a word of quechua origin (wanu), which means manure. Natural fertilizer formed by the accumulation of excrement of birds, especially of the area, which is a nocturnal bird that lives in caves and bats. Fiemo, fertilizer, manure. Guano is a natural fertilizer with high content of nitrogen, phosphorus and potassium, this is called colloquially the Triple 15 natural or Natural NPK.