复合改良剂对铅污染土壤中小白菜品质的影响

摘要

该研究采用盆栽试验,以小白菜为试验材料,种植在人工配置的不同浓度(800、1200、1600和2 000 mg/kg)的铅污染土壤中,研究不同浓度复合改良剂(0、600、900和1 200 mg/kg)对土壤有机质、pH、小白菜可食部位铅含量和营养品质的影响.结果表明,施用900 mg/kg复合改良剂可使Pb污染土壤的有机质含量提高24.19％～60.00％,但对土壤pH值无显著影响.施用复合改良剂可明显提高小白菜安全性和营养品质,4个铅处理中小白菜可食部位铅含量降低19.11％～35.72％,Vc含量增加13.27％～69.30％,可溶性糖含量提高54.17％ ～87.50％,干物质量提高28.36％～33.39％,粗纤维含量降低20.83％～31.03％.因此,复合改良剂能够用于重金属铅污染土壤的原位修复,推荐其适宜用量为900 mg/kg.%In the present study,a pot experiment was carried out to investigate the effects of a composite soil amendment at different levels (0,600,900 and 1 200 mg/kg) on the soil organic matter content,pH,Pb uptake and nutritional quality of pak choi (Brassica rapa L.Chinensis Group) grown in the soils contaminated by four levels (800,1 200,1 600 and 2 000 mg/kg) of Pb.The results showed that 900 mg/kg soil amendment increased the soil organic matter content by 24.19％-60.00％,but had no significant influence on soil pH.Comparing with control (without amendment application),the security and nutritional quality of pak choi were obviously improved by applying the soil amendment.In detail,900 mg/kg soil amendment improved the content of Vc of pak choi growing in 800,1 200,1 600 and 2 000 mg/kg Pb-contaminated soils by 13.27％-69.30％,the content of soluble sugar by 54.17％-87.50％,the dry matter weight by 28.36％-33.39％,and decreased the content of Pb by 19.11％-35.72％ and the content of crude fiber by 20.83％-31.03％,respectively.These data indicated that the composite amendment can be used for the in situ repair of Pb-contaminated soils,and the recommended dosage is 900 mg/kg.