排水洗盐对滨海盐碱地土壤性质和微生物群落多样性的影响

Drainage for decreasing salt affects the soil properties and microbial community diversity in coastal saline-alkali land

摘要:

目的 研究排水对滨海盐碱地土壤性质和微生物群落特征的影响。方法 以江苏南通滨海盐碱地排水洗盐前后的土壤为研究对象，通过一系列土壤物化性质表征和高通量测序方法，对土壤酸碱度、氮磷钾营养元素、生物酶活性以及土壤微生物群落结构进行分析，并采用生物信息学分析方法，剖析微生物群落结构特征与土壤物化性质的关联性以及可能的厌氧代谢过程。结果 排水洗盐明显降低了土壤的pH和电导率(electrical conductivity, EC)，但也一定程度上造成了土壤中营养成分的流失。洗盐后土壤中蔗糖酶、过氧化物酶活性以及真菌的物种丰富度和物种多样性有所升高，但细菌和古菌的物种丰富度和物种多样性降低。相关分析表明微生物群落结构与土壤电导率和钾元素含量呈显著正相关性，与土壤过氧化氢酶活性和土壤蔗糖酶活性呈显著负相关性。冗余分析和功能预测发现，真菌和古菌与电导率(EC)显著相关，而古菌可能通过对盐度的适应改变其群落结构。结论 排水洗盐降低了土壤中的盐度和pH，对土壤性质和微生物群落结构造成了影响。

Abstract:

Objective To study the effects of drainage on the soil properties and microbial community characteristics in coastal saline-alkali land.Methods Soil samples were collected before and after drainage for decreasing salt from the coastal saline-alkali land in Nantong, Jiangsu. The soil pH, nutrient elements (nitrogen, phosphorus, and potassium), enzyme activity, and microbial community structure were analyzed by soil physical and chemical property characterization and high-throughput sequencing. Bioinformatic analysis was conducted to study the correlations between microbial community structure characteristics and soil physical and chemical properties and the possible anaerobic metabolic process.Results Drainage for decreasing salt significantly reduced the soil pH and electrical conductivity (EC), while causing the losses of nutrients in the soil to a certain extent. After drainage, the activities of sucrase and peroxidase and the richness and diversity of fungi in the soil increased to a certain extent, while the richness and diversity of bacteria and archaea decreased. Principal component analysis showed that microbial community structure had significantly positive correlations with soil EC and potassium content, while it had significantly negative correlations with catalase and sucrase activities in the soil. Redundancy analysis and functional prediction showed that fungi and archaea were significantly correlated with EC, while archaea may change the community structure by adapting to salinity.Conclusion Drainage for decreasing salt reduced the salinity and pH in the soil, which affected the soil properties and microbial community structure.