RESUMO
Biochar is a solid material of biological origin obtained from the biomass carbonization, designed as a mean to reduce greenhouse gases emission and carbon sequestration in soils for a long time. Biochar has a wide spectrum of practical utilization and is applied as a promising soil improver or fertilizer in agriculture, or as a medium for soil or water remediation. Preparations of biochar increase plant growth and yielding when applied into soil and also improve plant growth conditions, mainly bio, physical and chemical properties of soil. Its physical and chemical properties have influence on bacteria, fungi and invertebrates, both in field and laboratory conditions. Such effects on rhizosphere organisms are positive or negative depending on biochar raw material origin, charring conditions, frequency of applications, applications method and doses, but long terms effects are generally positive and are associated mainly with increased soil biota activity. However, a risk assessment of biochar applications is necessary to protect the food production and soil environment. This should be accomplished by biochar production and characterization, land use implementation, economic analysis, including life cycle assessment, and environmental impact assessment.
