生物炭对土壤有效镉含量和甘蔗镉吸收的影响

Effects of Biochar on Available Cadmium Content in Soil and Cadmium Uptake in Sugarcane

为探求Cd污染的土壤添加生物炭对Cd从土壤-甘蔗迁移的影响,本研究以云蔗05-51为材料,采用盆栽试验,土壤生物炭含量分别设为0%、2.5%、5.0%,并加入不同量的Cd(NO_(3))_(2)·4H_(2)O到土壤,土样有效Cd含量设4个水平(0、100、250、500 mg/kg),共12个处理。在甘蔗幼苗期,对甘蔗株高、地上部分和根系的生物量进行测量,对甘蔗地上部分、根系的Cd含量和积累量进行测定,同时对土壤有效Cd含量进行测定。结果表明,在甘蔗幼苗期,土壤中0~500 mg/kg有效Cd对甘蔗株高、生物量积累抑制作用不明显。有效Cd浓度为250 mg/kg的处理,土壤有效Cd含量变化趋势为:5.0%生物炭<2.5%生物炭<0%生物炭。有效Cd浓度500 mg/kg处理85天后,甘蔗地上部分Cd含量趋势为:0%生物炭>2.5%生物炭>5.0%生物炭,各处理间差异显著(P<0.05)。有效Cd浓度为500 mg/kg、生物炭0%的处理,甘蔗根系Cd含量达最高值为131.86 mg/kg,甘蔗根系Cd积累量6.43 mg为最大值。土壤有效Cd浓度为100、500 mg/kg的处理,地上部分Cd积累量趋势为:5.0%生物炭<2.5%生物炭<0%生物炭。总的来说,土壤有效Cd浓度在0~500 mg/kg范围,云蔗05-51在苗期地上部分和根系的生物量积累不受抑制。云蔗05-51地上部分Cd积累量明显低于根系。添加生物炭后土壤有效Cd含量呈降低的趋势,甘蔗地上部分和根系Cd含量和积累量有一定程度的降低。

To investigate the effect of biochar addition on Cd migration from soil to sugarcane in Cd contaminated soil,Yunzhe05-51 was used as the material,and pot experiment was conducted with 12 treatments.Soil biochar content was designed to be 0%,2.5%and 5.0%,respectively,and different amounts of Cd(NO_(3))_(2)·4H_(2)O were added to the soil,available Cd content of soil samples was set at four levels(0,100,250 and 500 mg/kg).In the seedling stage of sugarcane,the plant height,biomass of overground part and root of sugarcane were measured,the content and accumulation of Cd in overground part and root of sugarcane were measured,and the content of available Cd in soil was measured.The result showed that during sugarcane seedling stage,available Cd with 0~500 mg/kg content had no obvious inhibition effect on plant height and biomass accumulation.When the available Cd concentration was 250 mg/kg,the variation trend of available Cd content of soil was 5.0%biochar<2.5%biochar<0%biochar.After 85 days of treatment with available Cd concentration of 500 mg/kg,the trend of Cd content in overground part of sugarcane was 0%biochar>2.5%biochar>5.0%biochar,and the difference between different treatments was significant(P<0.05).When the available Cd concentration was 500 mg/kg and 0%biochar,the highest value of Cd content of sugarcane root was 131.86 mg/kg,and the maximum value of Cd accumulation of sugarcane root was 6.43 mg.When soil Cd concentration was 100 and 500 mg/kg,the trend of Cd accumulation in overground part of sugarcane was 5.0%biochar<2.5%biochar<0%biochar.The available Cd concentration of soil ranged from 0 to 500 mg/kg,and the biomass accumulation of overground part and root of Yunzhe05-51 was not inhibited at seedling stage.Cd accumulation in the overground part of Yunzhe05-51 was significantly lower than that in root.The content of available Cd in soil decreased after biochar addition,and the content and accumulation of Cd in overground part and root of sugarcane were decreased.