胡萝卜对锌元素的反应

Carrot Response to Excessive Rates of Zn Application.

微区试验结果表明,土壤有效锌含量随锌肥施用量的增加而提高。各处理的土壤有效锌均在环境容量以下,不足以对作物产生毒害作用。胡萝卜鲜重产量以亩施20kgZnSO_4·7H_2O的处理为最高。其它处理并无显著差异。收获时茎叶含锌量占总吸收位的49～60％。对照处理的块根含锌量仅为7.63μg/g(以烘干重计),而亩施400kgZnSO_4·7H_2O的处理则为54.18μg/g,说明胡萝卜可以作为富锌作物,但其绝对富锌量尚嫌不足。

The experiment with carrot was conducted in screenhouse with 5 treatments of 0, 4, 20, 100 and 400 kg ZnSO4.7H_2O/mu. The result indicated that the soil available Zinc (Zn) content was increased as Zn application rates elevated. The soil Zn contents under all treatments were all below the criterion of soil environmental capacity and would not cause toxicity on carrot growth. The highest fresh yield of carrot was obtained in treatment with 20 kg Zn fertilizer per mu. There were no significant differences recorded among other treatments. The Zn concentration in the stem and leaves constituted 49-60％ of the total Zn uptake. The Zn concentration of carrot root in CK treatment was only 7.63 ug/g (dry matter basis), while that in treatment of 400 kg per mu was 54.18 ug/g. The conclusion of the experiment im plies that carrot is a vegetable which posses potential to enhance Zn uptake but its absolute Zn accumulation is rather limited. The authors believe that as far as carrot is concerned, Zn as a heavy metal micronutrient is only with very minimum phytotoxicity.