生物质炭添加对生菜Cd积累的影响

为探究添加生物质炭对Cd胁迫下生菜Cd吸收累积的影响，以生菜为试验材料，通过盆栽试验，在添加外源镉含量为3 mg/kg的土壤中分别添加0%、1%、2%、3%的生物质炭，待生菜收获后，测得土壤pH、有机碳、生菜产量、生菜体内Cd富集和转运情况及Cd在土壤中的赋存形态的数据。结果表明：添加生物质炭可以显著提高土壤有机碳含量(P≤0.05)，其中生物质炭添加量为3%，相比CK组土壤有机碳增加了35.14%～40.87%；添加生物质炭可以显著降低生菜Cd含量，尤其是3%量的生物质炭添加后，生菜叶Cd含量由0.79 mg/kg降低至0.44 mg/kg。生物质炭可以显著降低生菜中Cd的富集、转运系数，并使残渣态Cd含量增多，酸可提取态、可还原态、可氧化态Cd含量显著降低。因此，生物质炭的施用对Cd污染土壤和生菜体内Cd的积累有显著的阻控作用，特别是生物质炭添加量为3%时效果最优。

Effects of Biochar Addition on Cd Enrichment in Lettuce

To investigate the effect of biochar addition on the absorption and accumulation of Cd in lettuce under Cd stress, lettuce was used as the experimental material. By pot experiment, 0%, 1%, 2%, and 3% of biochar were added to the soil with exogenous Cd content of 3 mg/kg, respectively. After the lettuce was harvested, the data of soil pH, soil organic carbon, lettuce yield, Cd enrichment and translocation in lettuce, and the occurrence form of Cd in soil were measured. The results showed that the addition of biochar could significantly increase the content of soil organic carbon (P≤0.05). When the biochar addition amount was 3%, the soil organic carbon increased by 35.14%-40.87% compared with that of the CK group. The addition of biochar significantly reduced the Cd content of lettuce. Especially the addition of 3% of biochar, which could reduce the Cd content of lettuce leaves from 0.79 mg/kg to 0.44 mg/kg. Biochar can significantly reduce the enrichment factor and translocation factor of Cd in lettuce, increase the content of residual Cd, and significantly reduce the content of acid-extractable, reducible and oxidizable Cd. Therefore, the addition of biochar has a significant inhibitory effect on soil Cd contamination and Cd accumulation in lettuce, and 3% of biochar addition has the best effect.