Belozem saline soils microbiome

soils, characterized by high salinity and pH levels, have been the subject of research in many countries including Bulgaria. This is because 1% of the total land area in Bulgaria is covered by saline soils Penov et al.(2009) which accounts for approximately 55,000 hectares, comprising 35,500 hectares affected by natural salinization and 25,000 hectares influenced by industrial and drainage activities (Hristov, 2021). This is because the overall geographical characteristics of Bulgaria position it within the transit salt-regime zones, which are conducive to the development of salinization (Andreeva & Poushkarov, 2020). In essence, soil salinization can be categorized into two primary types based on the predominant influence of natural processes and anthropogenic factors known as primary salinization and secondary salinization respectively (Zhang et al., 2023). Salinization in Bulgaria is often a result of intensive irrigation, known as secondary salinization Penkov et al.(1985) and historical and ongoing tectonic events like earthquakes known as primary salinity. The factors contributing to soil salinization are varied and can manifest across various climatic conditions (Shahid et al., 2018).

具有高盐度与高pH值特性的土壤是包括保加利亚在内的多个国家的研究主题。据Penov等（2009）统计，保加利亚境内盐渍土（saline soils）占该国陆地总面积的1%，总面积约55000公顷，其中35500公顷受自然盐渍化影响，25000公顷受工业与排水活动干扰（Hristov，2021）。究其根源，保加利亚的整体地理区位使其处于过境盐类状况带（transit salt-regime zones），该环境有利于土壤盐渍化（soil salinization）的发育（Andreeva & Poushkarov，2020）。本质而言，依据自然过程与人为因素（anthropogenic factors）的主导作用，土壤盐渍化可分为两类主要类型：分别为原生盐渍化（primary salinization）与次生盐渍化（secondary salinization）（Zhang等，2023）。保加利亚的盐渍化通常由两类因素诱发：一类为集约化灌溉，由此引发次生盐渍化（Penkov等，1985）；另一类为历史及现今的构造活动（如地震），由此引发原生盐渍化。土壤盐渍化的诱发因素多样，可在多种气候条件下显现（Shahid等，2018）。