生物炭和枯草芽孢杆菌对Cd污染土壤中萱草生长和土壤修复的影响

Effects of Biochar and Bacillus subtilis on Daylily Growth and Soil Remediation in Cd-contaminated Soil

本研究旨在探讨生物炭和枯草芽孢杆菌对Cd污染土壤中大花萱草生长和土壤修复的影响。研究设置了四个处理组:(1)对照组(CK),不添加任何改良剂;(2)生物炭组(B),土壤添加3%生物炭;(3)枯草芽孢杆菌组(BS),土壤添加4×10~9CFU/kg土壤的枯草芽孢杆菌悬液;(4)生物炭+枯草芽孢杆菌组(B+BS),土壤同时添加3%生物炭和4×10~9CFU/kg土壤的枯草芽孢杆菌悬液。分别测定了各组大花萱草的农艺性状、净光合速率、蒸腾速率、生理指标、土壤p H、大花萱草中Cd含量以及土壤中有效态Cd含量。研究结果显示,相较于B组和BS组,B+BS组的大花萱草株高、叶面积、地上生物量和地下生物量显著增加(P<0.05)。与B组和BS组比较,B+BS组的净光合速率和蒸腾速率显著增加(P<0.05)。相较于B组和BS组,B+BS组的大花萱草含水量和叶绿素含量显著增加,而细胞膜透性、游离脯氨酸含量和可溶性糖含量显著降低(P<0.05)。与B组和BS组比较,B+BS组的土壤p H值显著增加(P<0.05)。与B组和BS组比较,B+BS组的大花萱草Cd含量和土壤中有效态Cd含量均显著降低(P<0.05)。综上所述,本研究表明,生物炭和枯草芽孢杆菌均能有效促进Cd污染土壤中大花萱草的生长,促进土壤修复,并且两者联用的效果最佳。

This study aims to investigate the effects of biochar and Bacillus subtilis on the growth of ornamental plant daylily(Hemerocallis fulva)and soil remediation in Cd-contaminated soil.Four treatment groups were established:(1)Control group(CK)with no amendment added to the soil;(2)Biochar group(B)with 3%biochar added to the soil;(3)Bacillus subtilis group(BS)with 4×109 CFU/kg soil of Bacillus subtilis suspension added to the soil;(4)Biochar+Bacillus subtilis group(B+BS)with 3%biochar and 4×109 CFU/kg soil of Bacillus subtilis suspension simultaneously added to the soil.Various agronomic traits,net photosynthesis rate,transpiration rate,physiological indicators,soil pH,Cd content in daylily,and available Cd content in soil were measured for each group.The results showed that compared to the B and BS groups,the B+BS group exhibited significantly increased plant height,leaf area,above-ground biomass,and below-ground biomass(P<0.05).The B+BS group also showed significantly higher net photosynthesis rate and transpiration rate compared to the B and BS groups(P<0.05).Moreover,the B+BS group had higher water content and chlorophyll content in daylily,while exhibiting significantly reduced cell membrane permeability,free proline content,and soluble sugar content(P<0.05).Additionally,the soil pH value was significantly higher in the B+BS group than in the B and BS groups(P<0.05).Furthermore,the B+BS group demonstrated significantly decreased Cd content in daylily and available Cd content in soil compared to the B and BS groups(P<0.05).Overall,the findings of this study indicate that both biochar and Bacillus subtilis effectively promote the growth of daylily in Cd-contaminated soil and facilitate soil remediation,with the combined application showing the best results.