生物炭复配调理剂对镉污染土壤性状和小白菜镉吸收及其生理特性的影响

Effects of biochar complex conditioner on properties of cadmium contaminated soil and cadmium absorption and physiological characteristics of Brassica chinensis

  • 摘要: 【目的】研究生物炭复配调理剂(由生物炭与泥炭、石灰混合配制而成)修复中轻度镉(Cd)污染农田土壤的可行性,为其在中轻度Cd污染农田土壤上的应用提供科学依据。【方法】在网室进行生物炭复配调理剂的盆栽试验,设4个不同的用量梯度,分别为0(对照)、80、160、240 g/盆,分别用H0、H1、H2和H3表示,每盆用土4 kg,每处理4次重复,研究不同生物炭复配调理剂用量对土壤性状、小白菜Cd吸收及其生理特性的影响。【结果】生物炭复配调理剂能显著提高土壤pH、土壤微生物氮(MBN)含量和脲酶活性(P<0.05,下同),同时显著降低土壤有效态Cd(DTPA-Cd)(最大降幅37.1%)、微生物碳(MBC)含量和酸性磷酸酶活性。生物炭复配调理剂能有效降低小白菜Cd吸收量(最大降幅85.7%),小白菜细胞中丙二醛(MDA)含量及超氧化歧酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性等抗逆性指标明显下降,同时小白菜Cd含量可降至0.10 mg/kg,符合食品安全标准;低用量(2%)的生物炭复配调理剂可使小白菜增产,高用量则不利于小白菜生长。【结论】生物炭复配调理剂可有效钝化土壤重金属Cd,改善土壤生化

     

    Abstract: ObjectiveThe present study was conducted to study the feasibility of utilization of biochar complex condi-tioner (biochar, peat and lime) in repairing light cadmium(Cd) contaminated farmland soil, in order to provide a scien-tific basis for its utilization on light Cd contaminated farmland. MethodA pot experiment was carried out in net house to investigate effects of biochar complex conditioner. Four treatments namely four dosage of biochar complex conditioner in-cluding 0(CK), 80, 160 and 240 g/pot were applied in this experiment. The four treatments were indicated as H0, H1, H2 and H3 respectively. Each treatment had one pot fitted with 4 kg soil and was repeated four times in a bid to study ef-fects of different -proportion biochar complex conditioners on soil characteristics, Cd uptake of Brassica chinensis and physiological parameters. ResultBiochar complex conditioner significantly improved soil pH, microbial nitrogen(MBN) content and urease activity(P<0.05, the same below), and reduced soil available Cd concentration(up to 37.1%), soil microbial carbon(MBC) content and acid phosphatase activity. In addition, biochar complex conditioner reduced Cd concentration(up to 85.7%), malondialdehyde(MDA) accumulation as well as activity of superoxide dismutase(SOD), catalase(CAT), peroxidase(POD) activity in plant of B. chinensis. Cd content of B. chinensis was down to 0.10 mg/kg, which met food safety standards. It was found that low dosage(2%) of biochar complex conditioner can increase yield of B. chinensis while high dosage had negative effect. ConclusionBiochar complex conditioner is effective in reducing soil Cd activity and improving soil conditions as well as inhibiting Cd uptake of plant. It means that biochar complex condition-er can be applied to remediation of Cd contaminated soil and the most appropriate dosage is 20-40 g/kg.

     

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