Soil salinization adversely affects soil quality and ecosystem. Many researches have tried to ameliorate saline soils by soil conditioners. However, little is known about the differences in the responses of soil bacterial communities to natural and artificial conditioners applied to saline soils. Therefore, in this study, the effects of natural humic acid (IK), synthetic polymer (IP), and composite material (IF) (mixture of IK and IP (1:1)) on bacterial community structure and functional genes in saline soil were evaluated to clarify their differences. The results showed that the application of the three soil conditioners significantly reduced soil pH and Na+ content but increased soil alkaline phosphatase, urease, invertase and catalase activities, bacterial diversity, and nutrients, compared to the control (no conditioner). IK application increased bacterial relative abundance (e.g., Subgroup_6, RB41, MND1, and KD4‐96) and metabolic functions (e.g., Two‐component system and Biosynthesis of amino acids) by increasing soil nitrogen and maintaining K+ and Na+ balance. IP application increased soil alkaline phosphatase and urease activities as well as bacterial relative abundance (e.g., Subgroup_6, RB41, MND1, Gemmatimonadaceae, and KD4‐96) and metabolic functions (e.g., Quorum sensing and carbon metabolism) by increasing soil organic carbon/nitrogen content. IF application increased the bacterial relative abundance of Subgroup_6, RB41, and MND1 by increasing soil available nitrogen and regulated their metabolic pathways (e.g., ABC transporters and microbial metabolism). On the whole, IK, IP, and IF could regulate the structure and function of soil bacterial community in saline soils. This study clarifies difference in the effects of different soil conditioners on the amelioration of saline soils from the perspective of soil microbiology, and provides a reference for the amelioration of saline soils in arid areas.

中文翻译：

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土壤调理剂对干旱区葡萄园盐渍土理化性质及细菌群落的影响

土壤盐碱化对土壤质量和生态系统产生不利影响。许多研究尝试通过土壤改良剂来改良盐渍土。然而，人们对土壤细菌群落对盐渍土中天然和人工调节剂的反应差异知之甚少。因此，本研究研究了天然腐植酸（IK）、合成聚合物（IP）和复合材料（IF）（IK和IP（1:1）的混合物）对盐渍土细菌群落结构和功能基因的影响。进行评估以澄清它们的差异。结果表明，施用3种土壤改良剂显着降低了土壤pH值和Na+含量，但与对照（无调节剂）相比，土壤碱性磷酸酶、脲酶、蔗糖酶和过氧化氢酶活性、细菌多样性和养分有所增加。 IK 应用增加了细菌相对丰度（例如，子组_6,RB41,神经元病1， 和KD4-96）和代谢功能（例如，双组分系统和氨基酸的生物合成）通过增加土壤氮和维持钾+和钠+平衡。 IP 应用增加了土壤碱性磷酸酶和脲酶活性以及细菌相对丰度（例如，子组_6,RB41,神经元病1,芽藻科， 和KD4-96）和代谢功能（例如，群体感应和碳代谢）通过增加土壤有机碳/氮含量。 IF 应用增加了细菌的相对丰度子组_6,RB41， 和神经元病1通过增加土壤有效氮并调节其代谢途径（例如 ABC 转运蛋白和微生物代谢）。总体而言，IK、IP、IF对盐渍土土壤细菌群落的结构和功能具有调节作用。本研究从土壤微生物学角度阐明了不同土壤改良剂对盐渍土改良效果的差异，为干旱地区盐渍土改良提供参考。