Data_Sheet_1_Optimal NPK Fertilizer Combination Increases Panax ginseng Yield and Quality and Affects Diversity and Structure of Rhizosphere Fungal Communities.docx

Soil microorganisms affect crop rhizospheres via the transformation and transport of nutrients, which has important influences on soil fertility, carbon sequestration, and plant yield and health in agroecosystems. There are few reports on the effects of fertilizer application on the growth of Panax ginseng (C. A. Mey.) or the structure of its rhizosphere microbial communities. In this study, an orthogonal experimental design was used to explore the effects of nine different combinations of nitrogen (N), phosphorus (P), and potassium (K) fertilizers with different amounts and proportions on ginseng growth and accumulation of ginsenosides and the structure of rhizosphere soil fungal communities. Soil without fertilization was the control. With the combined application of NPK, ginseng growth and development increased. The fertilization scheme N3P1K3, with N fertilizer at 50 g·m−2, P fertilizer at 15 g·m−2, and K fertilizer at 60 g·m−2, had the most comprehensive benefit and significantly increased ginseng rhizome biomass and ginsenoside contents (Rg1, Re, Rf, Rg2, Rb1, Ro, Rc, Rb2, Rb3, and Rd). Amplicon sequencing showed that NPK application increased the diversity of fungal communities in ginseng rhizospheres, whereas richness was bidirectionally regulated by proportions and amounts of NPK. Ascomycota was the dominant fungal phylum in ginseng rhizosphere soil, and relative abundances decreased with combined NPK application. Combined NPK application increased the relative abundance of potential beneficial fungi, such as Mortierella, but decreased that of potentially pathogenic fungi, such as Fusarium. Correlation analysis showed that potential beneficial fungi were significantly positively correlated with ginseng rhizome yield and ginsenoside contents, whereas the opposite relation was observed with potential pathogenic fungi. Thus, in addition to directly increasing crop growth, precise NPK application can also increase crop adaptability to the environment by shaping specific microbial communities. The results of this study suggest that the combined effects of biotic and abiotic processes on agricultural production determine crop yield and quality.

土壤微生物通过营养物质的转化与运输影响作物根际，这对土壤肥力、碳封存以及农业生态系统中的植物产量与健康具有重要意义。关于肥料施用对人参（C. A. Mey.）生长或其根际微生物群落结构影响的研究报道为数不多。在本研究中，采用正交实验设计，探究了不同用量及比例的氮（N）、磷（P）、钾（K）肥料九种不同组合对人参生长、人参皂苷积累以及根际土壤真菌群落结构的影响。未施肥的土壤作为对照。NPK肥料的综合施用促进了人参的生长与发展。其中，N3P1K3施肥方案，即氮肥用量为50 g·m−2，磷肥用量为15 g·m−2，钾肥用量为60 g·m−2，具有最全面的效益，显著提高了人参根茎的生物量和人参皂苷含量（包括Rg1、Re、Rf、Rg2、Rb1、Ro、Rc、Rb2、Rb3和Rd）。扩增子测序结果表明，NPK施用增加了人参根际真菌群落的多样性，而真菌丰富度则受NPK比例和用量的双向调控。子囊菌门是人参根际土壤中的优势真菌门类，其相对丰度随着NPK的联合施用而降低。NPK的联合施用增加了潜在有益真菌，如毛壳菌属的相对丰度，但降低了潜在致病真菌，如镰刀菌属的相对丰度。相关性分析表明，潜在有益真菌与人参根茎产量和人参皂苷含量呈显著正相关，而与潜在致病真菌呈负相关。因此，精确的NPK施用不仅能直接促进作物生长，还能通过塑造特定的微生物群落，增强作物对环境的适应性。本研究结果表明，生物和非生物过程对农业生产综合作用决定了作物的产量与品质。