选择生物质炭、钙镁磷肥、有机肥三种改良剂,在云南三七主产区进行田间试验,比较不同改良剂对降低五加科人参属三七(Panax Notoginseng)Cd含量的效果。结果表明,生物质炭和钙镁磷肥处理均显著降低了三七主根、剪口、茎、叶的Cd含量,降低幅度分别为25.4%~43.6%、40.2%~40.9%、34.3%~51.2%和33.0%~33.5%,且生物质炭、钙镁磷肥处理下三七主根干重较对照分别显著提高48.7%和50.4%;生物质炭和钙镁磷肥处理土壤有效Cd含量分别减少56.1%和58.1%,表明生物质炭和钙镁磷肥能有效降低土壤Cd生物有效性、抑制三七Cd吸收。这与生物质炭和钙镁磷肥处理通过降低土壤酸性、提高土壤CEC及有机质含量有关。有机肥处理三七植株生物量和三七各部位Cd含量与对照相比均无显著差异。此外,生物质炭和钙镁磷肥处理显著降低了三七主根、剪口、茎、叶Cd的富集系数(Accumulation coefficient,AF),对三七Cd转移系数(Transfer coefficient,TF)影响则不显著,而有机肥处理对三七Cd的AF与TF均无影响;各处理三七须根Cd的AF在2.84~4.64之间,显著高于其他部位,而三七主根、剪口、茎、叶等部位Cd的AF和TF均小于1,表明三七须根对土壤Cd富集能力较强而转移能力较差,Cd易集中于三七地下部,Cd污染土壤中施用生物质炭与钙镁磷肥能有效降低Cd在三七体内的富集。
A field trial was conducted to investigate the effects of biochar, calcium magnesium phosphate and manure on Cd uptake and accumulation by Panax Notoginseng in Yunnan Province. The results showed that biochar and calcium magnesium phosphate significantly increased the taproot biomass by 48.7% and 50.4% compared with control. Biochar and calcium magnesium phosphate significantly decreased Cd concentration in taproot, rhizome, leaf and stem by 25.4%~43.6%, 40.2%~40.9%, 34.3%~51.2% and 33.0%~33.5%. It may be attributed to the decreased acidy of soil, the increased soil organic matter and CEC, which resulted in decreased soil exchangeable Cd, with the application of biochar and calcium magnesium phosphate. The changes of biomass and Cd accumulation of Panax Notoginseng in manure treatment are not significantly compared to CK. The accumulation coefficients(AF)of Cd in Panax Notoginseng were decreased by addition of biochar and calcium magnesium phosphate, respectively, but the Cd transfer coefficient(TF) of each part of Panax Notoginseng were not significant in biochar and calcium magnesium phosphate treatments. The AF of fibril root is about 2.84 ~4.64 in all treatments, but the AF and TF of any parts of Panax Notoginseng are less than 1.0 except fibril root. It means that the fibril root can accumulate Cd from contaminated soil easily, but it's difficult to transport the accumulated Cd from fibril root to other parts. The application of biochar and calcium magnesium phosphate could be an environmentally friendly and efficient way to remediate Cd contaminated acidic soils and improve the safety of Panax Notoginseng.