田间条件下不同钝化材料对玉米吸收镉的影响研究

选取4种钝化材料（赤泥、海泡石、钙镁磷肥和磷矿粉）开展田间试验,研究它们对玉米吸收镉与土壤有效态镉的影响。结果表明,除海泡石外,施用其他3种钝化材料均能促进玉米生长,增加玉米叶、茎与籽粒的重量。4种钝化材料都能降低玉米对镉的吸收,其中：高量赤泥（用量1.5%）能明显降低玉米茎、叶片及籽粒中镉的含量,较对照分别降低60.6%、33.6%与49.3%;高量钙镁磷肥（用量900kg·hm-2）明显降低玉米籽粒中镉含量,较对照降低57.4%。4种钝化剂明显降低土壤EDTA提取态镉、DGT提取态镉的含量。其中,高量海泡石处理的EDTA提取态镉含量最低,高量赤泥次之;高量赤泥处理的DGT提取态镉含量最低。本试验结果表明,1.5%用量的赤泥是最佳的功能钝化材料。

Effects of Different Amendments on Cadmium Uptake by Maize Under Field Conditions

Field experiments were conducted to investigate the effects of four amendments （red mud, sepiolite, calcium magnesium phosphate and phosphate rock） on cadmium uptake by maize and the cadmium availability in soil. The results showed that with the except of sepiolite, three amendments could improve maize growth, increase the dry weight of leaves, stems and grains. All four amendments reduced cadmium uptake by maize. Compared to the control treatment, high application rate of red mud （the dosage was 22.5 t·hm-2）reduced cadmium concentration in stems, leaves and grains of the maize by 60.6%, 33.6% and 49.3% respectively. Especially, high application rate of calcium magnesium phosphate （the dosage was 0.9 t·hm-2） decreased cadmium concentration in grains by 57.4%. Four amendments significantly decreased the EDTA and DGT extracted Cd concentration in soil. The EDTA extracted Cd concentration was lowest in the treatment of high application rate sepiolite. The DGT Cd concentration was lowest in the treatment of high application rate of red mud. It demonstrated that red mud（the dosagewas 22.5 t·hm-2） was the best functional amendments.