添加生物炭对土壤镉形态和小白菜镉吸收的影响

Effect of Biochar Addition on Cadmium Speciation in Soil and Cadmium Uptake in Chinese Cabbage

为了深入研究生物炭对土壤镉(Cd)形态及对小白菜吸收镉的影响,研究采取盆栽试验,将小白菜种植于镉污染土壤中,通过添加不同质量分数的生物炭进行培养试验。试验共设CK(不添加生物炭)、T1(添加2%的生物炭)及T3(添加4%的生物炭)三个处理,每个处理进行三次重复。试验结果表明:添加生物炭可以显著提高供试土壤的pH,T1、T2处理可分别将土壤pH提高0.58、0.80个单位;随着生物炭添加量的增加,土壤中弱酸提取态镉与可还原态镉的含量降低,而可氧化态镉与残渣态镉的含量增加,且T2处理与T1处理相比效果更显著;添加生物炭可以显著减少小白菜吸收镉的量,T1和T2处理可以分别使小白菜对镉的吸收降低41.67%和75.00%。总的来说,添加生物炭可以降低土壤中有效态镉的含量并显著降低小白菜对镉的吸收量,是一种降低土壤镉危害、提高小白菜的食品安全性的有效方法。

In order to investigate the effect of biochar on cadmium(Cd) forms in soil and cadmium absorption in Chinese cabbage,the Chinese cabbage was planted in cadmium contaminated soil by pot experiment,and the culture experiment was conducted by addition of biochar with different mass fractions.The amount of biochar addition was set as CK(without biochar),T1(2% biochar) and T3(4% biochar),and each treatment was repeated three times.The results showed that the addition of biochar could significantly increase the pH of the tested soil.T1 treatment could increase the pH of the soil 0.58 units,T2 treatment could increase the pH of the soil 0.80 units.With the increase of biochar addition,the contents of weak acid extracted cadmium and reducible cadmium in soil decreased,while the contents of oxidized cadmium and residual cadmium increased,and the treatment effect of the more addition was more significant.The addition of biochar coud significantly reduce the amount of cadmium absorbed by Chinese cabbage.Compared with CK,the absorption of cadmium by Chinese cabbage under T1 and T2 treatment could reduce by 41.67% and 75.00%,respectively.In conclusion,the addition of biochar can reduce the content of available cadmium in soil and significantly reduce the uptake of cadmium by Chinese cabbage,which is an effective method to reduce the damage of soil cadmium and improve the food safety of Chinese cabbage.