Cd和Cu在草甸棕壤-植物系统中行为特性的研究

在沈阳生态站开展了重金属迁移积累行为特性的试验研究，探讨了不同重金属元素在土壤及作物体内迁移积累变化规律。外源重金属元素Cd、Cu施入土壤后，无论是低剂量还足高剂量处理，水田土壤Cd元素已迁移到45cm的深度，而Cu元素迁移到30cm的深度。早田土壤低剂量和高剂量处理Cd迁移到30cm，而Cu元素只有高剂量处理迁移到30cm的深度。土壤Cd、Cu元素向下层迁移的量微乎其微，重金属元素大多滞留在土壤表层。水稻、玉米吸收的Cd大部分积累在作物体的根和茎叶中，而Cu大部分积累在作物体的根系中，Cd、Cu籽实吸收量占植物体总吸收量的1．16％～3％。水稻、玉米地上部吸收Cd的量〉地卜部吸收Cu的量，在作物体中Cd的迁移能力强于Cu的迁移能力。

Behavioral characteristics of Cd and Cu in meadow brown soil-plant system

The migration and accumulation characteristics of various heavy metals in soils and plants were studied at Shenyang Ecological Experimental Station. After introduction of the heavy metals into the paddy soil, the downwards migration was 45 cm and 30 cm depth for Cd and Cu respectively regardless of the doses. In dry land, Cd migrated downwards to 30 cm-depth for both high and low doses whereas Cu migrated to 30 cm-depth only at high dose. Most of the introduced heavy metals were retained in the surface layer of the soil with only negligible amount migrating to sub-surface soil. The Cd absorbed by rice and corn was mainly accumulated in roots and stems. Cu was mainly accumulated in roots. 1.16%-3% of the total uptake by crops was accumulated in seeds. The uptake of Cd in the above ground parts was higher than that of Cu. The migration ability of Cd in the plants was higher than that of cu.