稻季磷锌处理对水稻和伴矿景天吸收镉的影响

Effect of Phosphate and Zinc Amendment at Paddy Season on Cadmium Absorption in Rice and Sedum plumbizincicola

  • 摘要: 超积累植物与农作物轮作或间套作是实现重金属污染土壤边生产边修复的重要方式。通过水稻和伴矿景天(Sedum plumbizincicola)轮作的盆栽试验来研究Cd污染酸性红壤上稻季增施P和Zn对水稻和后茬伴矿景天吸收Cd的影响。结果表明,稻季高P处理(400 mg·kg-1)土壤CaCl2提取态Cd含量较对照(100 mg·kg-1)有所降低,水稻秸秆Cd含量无明显影响,但秸秆向籽粒的转运系数显著降低;稻季Zn处理降低了土壤CaCl2提取态Cd含量,糙米Cd含量由0.21 mg·kg-1(对照)降低至0.15 mg·kg-1;稻季增施P和Zn对后茬伴矿景天生长及地上部Cd含量未产生明显影响;Zn处理促进了稻米和伴矿景天对Zn的吸收。稻季适当增施P和Zn降低了水稻Cd积累风险,而对后茬伴矿景天Cd吸收修复无影响,可作为Cd污染土壤水稻与伴矿景天轮作边生产边修复的调控手段。

     

    Abstract: Rotation or intercropping of hyperaccumulator and crop is an important way to realize the production while remediation on heavy metal polluted soils. The influence of phosphate (P) and zinc (Zn) amendments at rice growth season on cadmium (Cd) uptake in rice and succeeding Sedum plumbizincicola was studied in a pot experiment using Cd contaminated acid red soil through the rotations of rice and S. plumbizincicola. The results show that at the high P (400 mg·kg-1) treatment soil CaCl2 extractable Cd decreased compared with the control (100 mg·kg-1), and the Cd concentration in rice straw was not effected obviously, but the Cd transfer coefficient from straw to grain was significantly decreased in the rice season. The soil CaCl2 extractable Cd concentration reduced under Zn treatment, and the Cd concentration in brown rice was reduced from 0.21 mg·kg-1 (control) to 0.15 mg·kg-1. The P and Zn treatment at rice season had no obvious influence on the shoot biomass and Cd concentration of S. plumbizincicola at next season. Zn treatment at rice season increased Zn accumulation in rice and S. plumbizincicola. The P and Zn treatment at rice season could reduce the risk of Cd accumulation in rice and had no obvious effect on Cd removal by succeeding S. plumbizincicola. So adding Zn and P can be regarded as an adjustable way to treat Cd polluted soil with production while remediation.

     

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