Biochar is aromatic carbon rich-C used to improve soil fertility. This product is proposed as an alternative to face the climate change due to its ability to sequester atmospheric carbon. Its physical-chemical characteristics are influenced by the type of biomass and the conditions in which pyrolysis is developed. It has been demonstrated that this material can have high contents of N, P, K, Mg, Mn, Na, Ca, Cu, Zn, Co, Si, Mo, Cr, Ni, and other trace elements. Soil biochar application can induce morphophysiological and metabolic changes in plants and improve their interactions established with soil microorganisms, including mycorrhizal fungi, plant growth promoting bacteria and antagonistic fungi such as Trichoderma. Biochar can be enriched or combined with compost, fertilizers and beneficial microorganisms promoting growth and defense of plants against different pests. The interactive effect of biochar with earthworms is soil-specific, because it depends on the quality of the soil in which they come into contact. In addition, biochar is capable of suppressing different soil pests and inducing systemic resistance against foliar pathogens in some plants. The aim of this work was to analyze and summarize aspects related to biochar and plant nutrition, plant growth promotion, biochar and other soil organisms favoring the growth and development of plants, relationship of this product with the decrease/suppression of pests and the defense of plants, as well as some considerations about this product application.