生物炭对土壤镉的固化效果及韭菜生长的影响

Effect of biochar on the solidification of cadmium in soil and the growth of leek

为探究生物炭对土壤中总镉和镉不同形态含量、土壤化学性质及韭菜生长的影响,以添加氯化镉(CK)盆栽为对照,设置3个不同比例生物炭处理,测定韭菜生长期内以及收获后韭菜生物量和土壤中总镉含量、不同形态镉占比、土壤化学性质等指标。结果表明,与CK相比,添加不同比例生物炭改善了土壤的化学性质,土壤pH显著升高2%;韭菜生物量和株高、根长显著增加;降低土壤中交换态镉比例,增大铁锰氧化物结合态镉、有机物结合态镉、残渣态镉比例,从而降低植株中总镉含量2%。其中2%生物炭处理在提高韭菜品质和降低各部位镉含量方面效果最好,与CK相比,在不同收割期使土壤pH显著升高0.53~1.23,叶、茎、根生物量分别显著提高17.3%~32.6%、20.1%~58.6%、15.6%~30.5%,株高和根长分别显著提高4.4%~12.3%、12.6%~26.0%,叶、茎、根中总镉含量下降幅度分别为66.4%~93.6%、71.3%~92.7%、28.7%~59.0%,可在实际生产中推广应用。

To investigate the effects of biochar on the different forms of total cadmium and cadmium in soil,soil chemical properties,and the growth of Chinese chives,we used potted plants with added cadmium chloride(CK)as a control and set up three different ratios of biochar treatment:1%biochar+cadmium chloride(T1),2%biochar+cadmium chloride(T2),and 5%biochar+cadmium chloride(T3).The biomass of Chinese chives during and after harvest,the total cadmium content in the soil,and the proportion of different forms of cadmium,soil chemical properties and other indicators were measured.The results showed that compared with CK,adding different proportions of biochar improved soil chemical properties and significantly increased soil pH;the biomass,plant height,and root length of leeks significantly increased;reduced the proportion of exchangeable cadmium in soil,increased the proportion of iron manganese oxide bound cadmium,organic matter bound cadmium,and residual cadmium,thereby reducing the total cadmium content in plants.Among them,T2 treatment has the best effect on improving the quality of leeks and reducing the cadmium content in various parts,compared with CK,soil pH was significantly increased by 0.53-1.23,the biomass of leaf,stem and root were significantly increased by 17.3%-32.6%,20.1%-58.6%,15.6%-30.5%,plant height and root length were significantly increased by 4.4%-12.3%and 12.6%-26.0%,respectively,the total cadmium content in leaves,stems and roots decreased by 66.4%-93.6%,71.3%-92.7%and 28.7%-59.0%,respectively,which can be promoted and applied in practical production.