Effects of application of biochar from different raw materials combined with inorganic amendments on cadmium accumulation in pakchoi shoots and soil cadmium inactivation
Biochar is a cost-effective material for soil heavy metal inactivation.To investigate the effects of applica-tion of biochar from different raw materials combined with zeolite-lime on soil cadmium(Cd)inactivation and Cd content in the edible part of crop,biochar was prepared from 7 easily obtained and large amount agricultural wastes,and a pot experiment using the typical greenhouse vegetable soil with moderate Cd pollution in southern China was conducted in this study.It was found that there were significant(P<0.05)differences in the microstructure and basic physicochemical properties among the 7 kinds of biochar.The combination of biochar with inorganic agents could increase soil pH,organic matter content,electrical conductivity,cation exchange capacity,hydrolysable nitro-gen content,available potassium content and available phosphorus content,reduce soil available Cd content,and significantly increase the shoot dry weight of pakchoi compared than the blank control without application of passivat-ors,promote crop growth,and significantly decrease Cd content in shoot and Cd translocation factor.Compared to applying inorganic deactivators alone,application of biochar combined with inorganic amendments had better effects on improving soil physicochemical properties,promoting crop growth,and reducing Cd content in the edible part.