多元复合调理剂对镉砷污染农田土壤微生物群落结构的影响

通过温室盆栽试验，研究多元复合调理剂（石灰石、铁粉、硅肥和钙镁磷肥，简称LISP）对土壤基本理化性质、Cd和As的生物有效性和微生物群落结构的影响.结果表明，LISP可改变土壤基本理化性质，降低土壤有效态Cd和As含量，并改变土壤微生物群落结构.在0.4%的LISP添加下，土壤pH值、有效磷和总磷含量较CK处理分别显著（P< 0.05）提高0.57单位、130.6%和18.38%，同时土壤有效态Cd和As含量较对照分别显著（P< 0.05）降低21.76%和16.39%.高通量测序结果表明，添加LISP可维持污染土壤中正常微生物群落的多样性和丰富度，而显著改变土壤微生物群落的组成和结构，其中厚壁菌门、放线菌门和浮霉菌门等门水平物种的相对丰度增加，而绿弯菌门、酸杆菌门和疣微菌门等门水平物种的相对丰度降低.冗余分析和Mantel检验分析表明，土壤pH值、有效磷以及有效态Cd和As含量是影响土壤微生物群落结构的主要环境因子.上述结果表明，LISP是一种有效的、生态安全的调理剂用于农田土壤Cd和As污染土壤修复.

Effects of the multi-composite amendment on soil microbial community structure in Cd and As-contaminated paddy soil

The influence of multi-composite amendment (including limestone, iron powder, silicon fertilizer, and calcium magnesium phosphorus fertilizer, abbreviation for LISP) on soil basic physical and chemical properties, the bioavailability of Cd and As, and the microbial community structure were studied under greenhouse condition. The results showed that the LISP can change the soil basic physical and chemical properties, reduce the available content of Cd and As in soil, and change the soil microbial community structure. With the addition of 0.4% of LISP, soil pH, available phosphorus and total phosphorus were significantly (P<0.05) increased by 0.57units, 130.6%, and 18.38%, respectively, as compared with CK treatment, simultaneously soil available Cd and As content significantly (P<0.05) decreased by 21.76% and 16.39%, respectively. According to high-throughput sequencing results, LISP can maintain normal diversity and richness of the microbial community in the contaminated soil. However, LISP can significantly change the composition and structure of soil microbial community, especially increase the relative abundance of Firmicutes, Actinobacteria, and Planctomycetes, while decrease the relative abundance of Chloroflexi, Acidobacteria, and Verrucomicrobia in soil. Redundancy analysis and Mantel test showed that soil pH, available phosphorus, and available Cd and As were the main environmental factors to affect the soil microbial community structure. The results suggested that LISP is an effective and ecologically safe amendment for the remediation of paddy soil contaminated with Cd and As.