Data_Sheet_1_Soil fungal community is more sensitive than bacterial community to modified materials application in saline–alkali land of Hetao Plain.docx

Soil salinization has become a major challenge that severely threatens crop growth and influences the productivity of agriculture. It is urgent to develop effective management measures to improve saline–alkali soil. Thus, in this study, soil properties, microbial communities, and function under desulfurization gypsum (DE), soil amendment (SA), farm manure (FA), and co-application of desulfurization gypsum, soil amendment, and farm manure (TA) in a field experiment were examined by high-throughput sequencing. The results showed that the application of modified materials is an effective approach in improving saline–alkali soil, especially TA treatment significantly increased the content of available phosphorus (AP), available potassium (AK), soil organic matter (SOM), and alkaline hydrolysis nitrogen (AHN) and decreased pH, bulk density (BD), and electrical conductivity (EC). The application of modified materials resulted in notable enhancement in fungal diversity and altered the composition and structure of the fungal community. Conversely, the effect on the bacterial community was comparatively minor, with changes limited to the structure of the community. Regarding the fungal community composition, Ascomycota, Mortierellomycota, and Basidiomycota emerged as the dominant phyla across all treatments. At each taxonomic level, the community composition exhibited significant variations in response to different modified materials, resulting in divergent soil quality. The TA treatment led to a decrease in Mortierellomycota and an increase in Ascomycota, potentially enhancing the ability to decompose organic matter and facilitate soil nutrient cycling. Additionally, the sensitivity of fungal biomarkers to modified materials surpassed that of the bacterial community. The impact of modified materials on soil microbial communities primarily stemmed from alterations in soil EC, AP, AK, and SOM. FUNGuild analysis indicated that the saprotroph trophic mode group was the dominant component, and the application of modified materials notably increased the symbiotroph group. PICRUSt analysis revealed that metabolism was the most prevalent functional module observed at pathway level 1. Overall, the application of modified materials led to a decrease in soil EC and an increase in nutrient levels, resulting in more significant alterations in the soil fungal community, but it did not dramatically change the soil bacterial community. Our study provides new insights into the application of modified materials in increasing soil nutrients and altering soil microbial communities and functions and provides a better approach for improving saline–alkali soil of Hetao Plain.

土壤盐渍化已成为严重威胁作物生长、制约农业生产力的重大挑战，亟须研发有效的治理措施以改良盐碱土壤。据此，本研究通过田间试验，采用高通量测序技术，对脱硫石膏（desulfurization gypsum, DE）、土壤改良剂（soil amendment, SA）、农家肥（farm manure, FA）以及三者配施（desulfurization gypsum, soil amendment and farm manure, TA）处理下的土壤属性、微生物群落及其功能进行了探究。研究结果表明，施用改良材料是改良盐碱土壤的有效途径；其中TA处理可显著提升有效磷（available phosphorus, AP）、速效钾（available potassium, AK）、土壤有机质（soil organic matter, SOM）与碱解氮（alkaline hydrolysis nitrogen, AHN）的含量，同时降低土壤pH值、容重（bulk density, BD）与电导率（electrical conductivity, EC）。施用改良材料可显著提升真菌多样性，并改变真菌群落的组成与结构。与之相对，改良材料对细菌群落的影响相对微弱，仅局限于群落结构的改变。就真菌群落组成而言，子囊菌门（Ascomycota）、被孢霉门（Mortierellomycota）与担子菌门（Basidiomycota）为所有处理下的优势菌门。在各分类学水平上，群落组成随不同改良材料呈现显著差异，进而引发土壤质量分化。TA处理可降低被孢霉门的相对丰度，提升子囊菌门的占比，这可能增强土壤有机质分解能力并促进土壤养分循环。此外，真菌生物标志物对改良材料的敏感性显著高于细菌群落。改良材料对土壤微生物群落的影响主要源于土壤EC、AP、AK与SOM的含量变化。FUNGuild分析显示，腐生营养型功能类群为群落优势组成部分，而改良材料的施用可显著提升共生营养型类群的占比。PICRUSt分析表明，在功能通路一级水平上，代谢功能是最为普遍的功能模块。总体而言，施用改良材料可降低土壤电导率、提升土壤养分水平，对土壤真菌群落的改变更为显著，但未对土壤细菌群落造成剧烈扰动。本研究为改良材料在提升土壤养分、调控土壤微生物群落与功能方面提供了新的理论视角，并为河套平原盐碱土壤的改良提供了更优方案。