不同原料生物炭与无机钝化剂配施对小白菜地上部镉积累和土壤镉钝化的影响

Effects of application of biochar from different raw materials combined with inorganic amendments on cadmium accumulation in pakchoi shoots and soil cadmium inactivation

生物炭是量大价廉的土壤重金属钝化材料。为探明不同原料生物炭与石灰沸石复配对土壤镉钝化与作物可食部镉含量的影响,用7种量大易得的农业废弃物制备生物炭,并采用南方典型镉中度污染温室菜地土壤进行小白菜盆栽试验。结果显示,7种生物炭的微观结构和基本理化性质存在显著(P<0.05)差异,但与无机钝化剂复配后有助于提高土壤pH值、有机质含量、电导率、阳离子交换量、碱解氮含量、速效钾含量和有效磷含量,降低土壤有效态Cd含量,且均较不施用钝化剂的空白对照显著提高了小白菜的地上部干重,促进了小白菜生长,显著降低了小白菜的地上部镉含量和镉转运系数。与单施无机钝化剂相比,配施生物炭在改善土壤理化性质、促进作物生长、降低可食部镉含量等方面效果更好。

Biochar is a cost-effective material for soil heavy metal inactivation.To investigate the effects of application 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 nitrogen 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 passivators,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.