丝瓜与伴矿景天间作对土壤Cd形态及丝瓜Cd吸收的影响

采用盆栽实验将丝瓜和超积累植物伴矿景天间作于重金属污染土壤中,并向土壤添加钙镁磷肥或向丝瓜根际添加固镉菌剂,研究间作对土壤Cd的形态及丝瓜重金属积累性的影响。结果表明,丝瓜与伴矿景天间作一定程度上减少了丝瓜的结果数量,同时存在增大丝瓜果实中Cd含量的风险;通过施加固镉菌剂或钙镁磷肥增加了丝瓜的结果数,且丝瓜果实中Cd含量均未超过国家标准的限定值。同时,景天和丝瓜对土壤Cd具有移除能力,丝瓜主要表现在茎叶对Cd的吸收,其中重污染土壤中的景天和丝瓜对土壤Cd的移除能力大于低污染土壤种植的景天和丝瓜。总体来看,丝瓜与超积累植物伴矿景天间作可用于低污染土壤进行边修复边生产。但是,由于存在较高食品安全风险,在间作的同时可采取施固镉菌剂或钙镁磷肥等措施来降低果实部分Cd含量。

Investigating the intercropping effects of Sedum plumbizincicola and Luffa cylindrical on soil cadmium fractions and cadmium uptake by Luffa cylindrical

Natural occurring processes particularly human activities contribute to release heavy metals in the environment. Cadmium(Cd) is a widespread heavy metal now, released into the environment through various activities. Cadmium uptake by crops is a serious concern because of its potential toxicity to humans. A pot experiment was conducted to investigate the effects of Luffa cylindrica intercropped with zinc/cadmium hyperaccumulator Sedum plumbizincicola, calcium magnesium phosphate was added, and immobilized cadmium bacteria were inoculated, the soil Cd fractions and Luffa cylindrica''s heavy metal accumulation in polluted soil were studied. The results showed that the fruit number was reduced and Cd concentration was increased in the treatment of Luffa cylindrica and Sedum plumbizincicola intercropping, while the fruit number was increased by inoculation with cadmium stabilizing bacteria or addition of calcium magnesium phosphate, more over the Cd concentrations in fruit of Luffa cylindrica didn''t exceed the national standard. Furthermore, Sedum plumbizincicola and Luffa were found to have strong extraction ability of Cd. In heavily polluted soil, Luffa had higher ability of Cd removal than in the lightly polluted soil. Therefore, Luffa cylindrica and hyperaccumulator Sedum plumbizincicola intercropping assisted by immobilized cadmium bacteria or calcium magnesium can be used for remediation and production in lightly contaminated soil to reduce Cd contents in edible part of crops.