在干旱地区,淡水资源不足,农业用水主要依靠浅层咸水。然而,长期的盐渍灌溉会导致土壤盐分积累和土壤环境恶化,不利于作物生长。在这项研究中,基于淡水(0.35dS·m-1,FW)和盐水(8.04dS·m-1,SW)的长期灌溉,通过等碳设计将生物炭(3.7t·hm-2,BC)和秸秆(6t·hm-2,ST)添加到土壤中。旨在阐明生物炭和秸秆还田对盐渍化土壤理化性质和微生物群落结构的影响。结果表明,盐渍灌溉显著增加了土壤含水量,电导率,有效磷,但显著降低了pH值和速效钾含量。有效磷的含量,有效钾,生物炭和秸秆还田显著增加了土壤总碳,但盐水灌溉土壤的电导率值显著下降。各处理中的优势菌为变形杆菌,放线菌,酸杆菌,绿菌,和蓝单胞菌.盐水灌溉显着增加了白单胞菌和变形杆菌的相对丰度,但显着降低了酸细菌和放线菌的相对丰度。在淡水灌溉的条件下,生物炭的返回显着降低了绿藻的相对丰度。秸秆还田显著提高了变形杆菌的相对丰度,但显著降低了酸性杆菌的相对丰度,放线菌,叶绿体,和蓝单胞菌.在盐水灌溉下,生物炭返回田地后,绿藻和蓝单胞菌的相对丰度显着降低。秸秆还田显著提高了变形杆菌的相对丰度,但显著降低了酸性杆菌的相对丰度,放线菌,叶绿体,和蓝单胞菌.LEfSe分析表明,盐水灌溉降低了土壤微生物的潜在标记和功能数量。在盐水灌溉下,生物炭返回增加了土壤微生物潜在标记的数量和功能。秸秆还田增加了土壤微生物潜在标记的数量。RDA结果表明,土壤微生物群落和功能结构与EC1:5、SWC、和pH。盐水灌溉会恶化土壤环境,不利于农业生产,其中EC1:5,SWC,pH和pH是驱动土壤微生物群落和功能结构变化的重要因素。利用生物炭和秸秆还田,可以减少盐对土壤和农作物的危害,为提高农业生产力奠定基础。
In arid areas, fresh water resources are insufficient, and agricultural water mainly depends on shallow saline groundwater. However, long-term saline irrigation will cause soil salt accumulation and soil environment deterioration, which is not conducive to crop growth. In this study, based on the long-term irrigation of fresh water (0.35 dS·m-1, FW) and saline water (8.04 dS·m-1, SW), biochar (3.7 t·hm-2, BC) and
straw (6 t·hm-2, ST) were added to the soil by an equal-carbon design. The aim was to clarify the effects of biochar and
straw returning on the physical and chemical properties and microbial community structure of salinized soil. The results showed that saline irrigation significantly increased soil water content, electrical conductivity, available phosphorus, and total carbon content but significantly decreased pH value and available potassium content. The contents of available phosphorus, available potassium, and total carbon in soil were significantly increased by biochar and
straw returning, but the conductivity value of soil irrigated with saline water was significantly decreased. The dominant bacteria in each treatment were Proteobacteria, Actinomycetes, Acidobacteria, Chloromycetes, and Blastomonas. Saline water irrigation significantly increased the relative abundance of Blastomonas and Proteobacteria but significantly decreased the relative abundance of Acidobacteria and Actinobacteria. Under the condition of fresh water irrigation, the relative abundance of Chlorocurvula was significantly reduced by the return of biochar. Straw returning significantly increased the relative abundance of Proteobacteria but significantly decreased the relative abundance of Acidobacteria, Actinomyces, Chloromyces, and Blastomonas. Under saline irrigation, the relative abundance of Chlorocurvula and Blastomonas were significantly reduced by biochar return to field. Straw returning significantly increased the relative abundance of Proteobacteria but significantly decreased the relative abundance of Acidobacteria, Actinomyces, Chloromyces, and Blastomonas. LEfSe analysis showed that saline irrigation decreased the potential markers and functional numbers of soil microorganisms.Under saline irrigation, biochar returning increased the number of potential markers and functions of soil microorganisms.
Straw returning to field increases the number of potential markers of soil microorganisms. RDA results showed that soil microbial community and functional structure were significantly correlated with EC1:5, SWC, and pH. Saline water irrigation will deteriorate the soil environment, which is not conducive to agricultural production, among which EC1:5, SWC, and pH are important factors driving changes in soil microbial community and functional structure. Using biochar and
straw to return to the field can reduce the harm of salt to soil and crops, laying a foundation for improving agricultural productivity.