根际效应对狼尾草降解土壤中阿特拉津的强化作用

Enhancement of atrazine degradation in soils caused by rhizosphere effects of Pennisetum

采用盆栽根袋培养法,研究了根际效应在狼尾草降解土壤阿特拉津中的作用。结果表明,盆栽培养28 d后,狼尾草对土壤中阿特拉津有较好的根际强化降解效果,狼尾草根际土壤阿特拉津去除率为52.70%,非根际土壤的阿特拉津去除率为37.60%。土壤自身具有修复阿特拉津的潜能,无狼尾草处理的湛江砖红壤中阿特拉津降解以非生物降解为主,降解率为16.90%,土著微生物对阿特拉津的生物降解效果弱于非生物降解,仅为11.70%。狼尾草通过根际效应显著提高了土壤总微生物数量和活性,增加了土壤可培养细菌、真菌和放线菌的数量,尤其是土壤可培养细菌数量,提升了土壤细菌群落结构的丰富度和均匀度,进而间接强化土壤阿特拉津的生物降解。

This study investigated the effect of Pennisetum rhizosphere on the atrazine degradation in laterite soil, using pot experiment method. The results showed that Pennisetum had an excellent effect on promoting atrazine degradation, which was mainly contributed by its rhizosphere effect. After pot culture of 28 days, the removal rate of atrazine in Pennisetum rhizosphere soil was 52.70%, while the removal rate in non-rhizosphere soil was 37.60%. Soil itself had a potential of atrazine removal, the atrazine removal was given priority to with non- biodegradation in laterite soil at Zhanjiang, and the degradation rate was 16.90%. The biodegradation effect driven from the indigenous mi- crobes was weaker than non-biodegradation, with 11.70% of degradation rate. The rhizosphere effect of Pennisetum significantly improved soil microorganism quantity and activity, increased the amount of cultivable bacteria, fungus and actinomyces in soils, especially the amount of cultivable bacteria, and improved the richness and evenness of the soil bacterial community.