锑污染土壤中添加蚯蚓对油菜生长及土壤特性的影响

Effects of earthworms in antimony-contaminated soil on rape growth and soil characteristics

为探究蚯蚓对锑污染土壤中油菜的生长及根际土壤特性的影响,通过盆栽培养试验,研究了赤子爱胜蚓添加后锑污染下油菜幼苗生物量、富集系数的变化,并从根际土壤养分、酶活性和细菌群落结构3个方面初探了锑污染状况下蚯蚓对油菜富集锑的影响机制。结果表明:锑污染土壤中,赤子爱胜蚓可以提高油菜的生物量以及锑的富集,南油杂1号锑的富集含量达到358.30mg·kg^(-1);锑显著抑制了过氧化氢酶、蔗糖酶和脲酶活性(P<0.05),蚯蚓显著提高了锑胁迫下两个油菜品种根际土壤的过氧化氢酶、蔗糖酶和脲酶活性(P<0.05),最大激活率分别为13%~31%、15%~48%和24%~44%;冗余分析表明全磷、全氮、碱解氮是影响土壤酶活性变化的重要因子;添加蚯蚓未改变油菜根际土壤中优势菌门的组成,主要增加了Bacteroidetes、Cyanobacteria和Chloroflexi的丰富度,其中Bacteroidetes与过氧化氢酶、脲酶活性呈极显著正相关(P<0.01)。研究表明,蚯蚓-油菜联合能降低农田土壤中锑的含量,起到一定的生态修复效果,南油杂1号的修复潜能大于沣油958。

To explore the effects of earthworms on the growth and enrichment in oilseed rape under antimony stress,the effects of Eisenia fetida on the biomass and heavy metal bioconcentration of oilseed rape in antimony-contaminated soil were studied via a pot experiment.The rhizosphere soil characteristics of oilseed rape under antimony pollution and the effects of E.fetida were analyzed from three perspectives:soil nutrients,enzyme activities,and bacterial communities.The results showed that:in antimony-contaminated soil,E.fetida could increase the biomass of oilseed rape and promote the enrichment of antimony in oilseed rape.The enrichment content of antimony in Nanyouza No.1 reached 358.30 mg∙kg^(-1).Antimony significantly inhibited the activities of catalase,sucrase,and urease(P<0.05).E.fetida significantly increased these activities in the rhizosphere soil of the two cultivars of oilseed rape.The maximum activation rates were 13%–31%,15%–48%and 24%–44%,respectively.Redundancy analysis showed that total phosphorus,total nitrogen,and available nitrogen were important factors affecting soil enzyme activity.The addition of E.fetida did not change the composition of dominant bacteria in the rhizosphere soil of oilseed rape,but mainly increased the abundance of Bacteroidetes,Cyanobacteria,and Chloroflexi.Among them,Bacteroidetes were significantly correlated with catalase and urease activity.The combination of earthworms and oilseed rape might lower the level of antimony in agricultural soil and contribute in certain ways to remediation.Compared to Fengyou 958,Nanyouza 1 has a greater potential for antimony removal.