开垦对盐渍化弃耕地土壤细菌群落组成和结构的影响

【目的】新疆盐碱弃耕地开垦后用于棉花的种植,研究比较开垦前后土壤细菌群落的变化,分析开垦对土壤质量和功能的影响。【方法】通过Illumina MiSeq测序,比较弃耕地与开垦后种植棉花的土壤细菌群落的组成和多样性;探索菌群所具有的特定功能。【结果】开垦显著地降低了土壤电导率和速效钾含量,显著地增加了土壤有机质、碱解氮和速效磷含量。弃耕地开垦为棉田后增加了细菌物种的丰富度和多样性。Proteobacteria和Firmicutes是弃耕地土壤中主要的细菌门。开垦降低了Firmicutes的相对丰度,但是增加了Chloroflexi, Acidobacteria和Actinobacteria的相对丰度。聚类分析显示弃耕地与开垦后农田的细菌群落有明显的差异性。【结论】开垦后进行棉花生产提高了土壤理化特性,改变了土壤细菌群落组成和结构。

Effects of Reclamation on the Composition and Structure of Soil Bacterial Communities in Abandoned Salinized Farmland

【Objective】 Abandoned salinized land in Xinjiang of China is being reclaimed for cotton production. The effect of reclamation on soil quality and function was obtained by comparing the changes of soil bacterial communities before and after reclamation.【Method】The specific objectives of this field study were: (1) to compare bacterial composition and diversity in unfarmed (i.e., unreclaimed) and cropped soils and (2) to explore the specific functions of the flora identified by Illumina MiSeq sequencing.【Result】Reclamation significantly reduced soil EC and available K, and significantly increased SOM, available N, and available P. Bacterial species richness and diversity increased when abandoned farmland was reclaimed for cotton production. Proteobacteria and Firmicutes were the dominant phyla in unfarmed soil. Reclamation reduced the relative abundance of Firmicutes, but increased the contents of Chloroflexi, Acidobacteria, and Actinobacteria. Cluster analyses showed that there was a significant difference in the bacterial community between the abandoned farmland and the cultivated land after the reclamation.【Conclusion】In general, cotton production after reclamation improved soil physical and chemical properties and changed the structure and composition of soil bacterial communities compared with unfarmed soil.