三种肥料对镉污染土壤中小白菜吸收镉的影响

为了评价施用不同肥料对小白菜富集污染土壤镉的效果,通过盆栽试验研究普通复合肥、有机肥和缓释氮肥3种肥料及其不同用量对小白菜在镉污染土壤中吸收镉的影响。结果表明,与对照相比,施用肥料增强了小白菜对镉的吸收。施用普通复合肥的处理富集镉的效果最高,其次是施用缓释氮肥和有机肥的处理。根部镉含量分别提高了23.80%~26.53%、19.93%~21.48%和10.17%~15.88%。小白菜地上部Cd含量分别提高了11.79%~25.47%(普通复合肥)、9.49%~13.82%(缓释氮肥),而施有机肥降低了小白菜地上部Cd含量。在所有种植(包括施肥和未施肥的)的小白菜中,根部镉含量明显高于地上部分,是地上部分镉含量的2.28~2.74倍。同时,肥料施用增加了小白菜对镉的富集系数,根部的富集系数是茎叶的2倍左右。施用普通复合肥和缓释氮肥增加了土壤有效态镉含量,分别增加了12.16%~39.64%和1.35%~18.92%;施用有机肥降低了土壤有效态镉含量,分别降低了16.22%和7.66%。研究结果对小白菜修复镉污染的土壤具有重要的理论意义和借鉴价值。

Effects of three fertilizers on Cd uptake by pakchoi in Cd contaminated soil

The effects of three fertilizers on the absorption of cadmium ( Cd) in pakchoi were investigated by pot experiment. The results showed that, the concentration of Cd in pakchoi with the application of fertilizers was higher than those without the application of fertilizers. The concentration of Cd in treatments of compound fertilizers was the highese, followed by treatments of controlled-release nitrogen fertilizers and then organic fertilizers. Compared with control, the concentrations of Cd were in-creased by 23. 80% ~26. 53%, 19. 93% ~21. 48%, 10. 17% ~15. 88% for roots of rape, and 11. 79% ~25. 47% and 9. 49% ~13. 82% for aboveground parts, respectively. The cadmium contents in roots were 2. 28 ~2. 74 times more than those in aboveground parts. The application of fertilizer increased the bio-concentration factor ( BCF) , and the BCF in roots was twice of those in stems and leaves. The results indicated that the contents of bio-available Cd in soil with compound fertiliz-ers and controlled-release nitrogen fertilizers increased by 12. 16% ~39. 64% and 1. 35% ~18. 92% respectively, compared with that in the control soil. However, those in soil with organic fertilizers were reduced by 16. 22% and 7. 66%. The conclu-sion is important to pakchoi for soil remediation.