蚯蚓和有效微生物群对果园土壤镉吸附—解吸及苹果镉含量的影响

The Effects of Earthworms and Effective Microorganisms on the Adsorption-Desorption of Cadmium in Orchard Soils and Cadmium Accumulation in Apple

以果园棕壤土和3年生盆栽苹果(Malus domestica Borkh.)为试验材料,研究引入蚯蚓和有效微生物群(EM)后,土壤对镉离子(Cd2+)的吸附-解吸行为及苹果根系和果实镉含量的变化。结果表明,随着土壤Cd2+含量增加,土壤对Cd2+的吸附率降低,解吸率提高;Langmuir方程显示,经过蚯蚓和EM处理的土壤对Cd2+的吸附强度和对Cd2+的最大缓冲容量(MBC)下降;在土壤Cd2+含量较高时,蚯蚓和EM降低了土壤对Cd2+的吸附率,提高了解吸率,EM效果更明显。苹果根系和果实镉含量随着土壤施Cd2+而增加,蚯蚓和EM明显促进根系对镉的吸收及镉在果实中的积累,在土壤镉含量较高时,蚯蚓和EM的作用更显著。

The Cd^2＋ adsorption - desorption in soil and the content Of Cd^2＋ in roots and fruits were studled by treatment with the earthworm and effective microorganisms （EM）, using the orchard brown soils and potted three-year-old apple trees （Malus domestica Borkh. ） as materials. The results showed that the adsorption ratio of the Cd^2＋ in the soils reduced and the desorption ratio of Cd^2＋ enhanced as the soil Cd^2＋. concentration increasing. According to the Langmuir equation, the adsorption strength and the maximum buffering capacity （MBC） of the soil to Cd^2＋ decreased after the soil was treated with the earthworm and EM. The earthworm and EM reduced the adsorption ratio of the soil for Cd^2＋ and increased Cd^2＋ desorption ratio in the soil of higher Cd^2＋ concentration. And the EM had more obvious effect compared with earthworm. In the root and fruit, Cd content increased with Cd^2＋ concentration increasing in the soil. The earthworm and EM significantly promoted the uptake of Cd^2＋ in the root and the accumulation of Cd^2＋ in the fruit, and the effect was more remarkable when the Cd^2＋ concentration was higher in the soil.