ABSTRACT
Biochar is a carbonaceous by-product obtained by pyrolysis of organic biomass. This recalcitrant material is used as an organic amendment for promoting soil quality, and as a sorbent substrate for the remediation of contaminated soils. However, the impact of biochar on soil organisms (micro-, meso- and macrofauna) and biochemical processes of soil functioning demands further research and methods for its ecotoxicological assessment. In particular, soil enzymes, which are essential biomolecules in soil nutrient cycling, have received little attention as molecular targets of biochar toxicity. The purpose of this chapter is, therefore, to examine the current knowledge on the impact of biochar on soil enzyme activities. The first section of the chapter will describe the impact of pesticides, mainly organophosphorus pesticides, on soil enzyme activities. The second section will provide an overview of soil enzyme responses to biochar application. The third section, presented as a case study, will illustrate how certain soil enzyme activities can be used as indicators of the impact of biochar on the availability and toxicity of pesticides.
