有机无机肥配施对大豆农田土壤养分及微生物群落结构与功能的影响

Combined application of organic and inorganic fertilizers affects soil nutrients and microbial community structures and functions in soybean fields

摘要:

目的 探究有机无机肥配施对大豆农田土壤养分含量、微生物群落结构与功能的影响，旨在为大豆农田土壤合理施肥以及大豆优质高产提供科学依据。方法 试验设置4个施肥处理：对照组(CK：不施肥)、施无机肥组(CF：复合肥)、施有机肥组(OF：干鸡粪)和有机无机肥配施组(OCF：干鸡粪+复合肥)。试验期间分别测定供试土壤的有机质(soil organic matter, SOM)、碱解氮(alkali-hydrolyzed nitrogen, AN)、速效磷(available phosphorus, AP)、速效钾(available potassium, AK)含量，以及微生物群落的结构与功能，探究微生物群落与土壤养分之间的关系。结果 不同施肥措施对大豆农田土壤养分的影响差异显著。在OCF处理下，土壤SOM、AN、AP含量和AK较CK分别提高了60.67% (P<0.05)、68.09% (P<0.001)、15.18倍(P<0.001)和59.54% (P<0.01)，但土壤pH有所升高。扩增子测序结果显示，不同施肥措施未改变土壤微生物的群落组成，但影响了门和属的相对丰度。与CK相比，OCF处理下担子菌门(Basidiomycota)和被孢霉门(Mortierellomycota)的相对丰度增加了5.62倍和4.51%，而子囊菌门(Ascomycota)的相对丰度降低了38.35%。OCF处理显著降低了真菌群落的丰富度和多样性(P<0.05)。α多样性分析发现，施入有机肥后细菌和真菌的多样性均降低，尤其是真菌α多样性降低最为显著(P<0.05)。功能预测显示，细菌群落中新陈代谢功能通路以氨基酸代谢的相对丰度占比最高，说明有机-无机肥配施促进了以氮素同化和蛋白质合成为核心的代谢过程，有利于细菌群落参与土壤养分转化。在OF处理下，共生营养型真菌的相对丰度最高，表明有机肥促进了真菌在土壤养分循环中的生态功能。结论 有机-无机肥配施能够有效调节土壤pH，缓解土壤酸化，提高土壤养分含量。真菌群落对有机肥更为敏感，施用有机肥显著降低其多样性，且能够刺激部分病原型真菌繁殖，而无机肥能够抑制病原型真菌的相对丰度。因此，有机-无机肥配施在协调土壤养分供给与微生物群落结构、优化土壤微生物功能组成方面具有明显优势，可为大豆农田实现高效、绿色和可持续施肥管理提供理论依据与实践参考。

Abstract:

Objective To investigate the effects of combined application of organic and inorganic fertilizers on soil nutrient content and microbial community structures and functions in soybean fields, thus providing a scientific basis for rational fertilization and high-quality, high-yield soybean production.Methods Four fertilization treatments—control (CK: no fertilization), inorganic fertilizer (CF: compound fertilizer), organic fertilizer (OF: dry chicken manure), and combined organic-inorganic fertilizers (OCF: dry chicken manure+compound fertilizer)—were established. During the experiment, soil organic matter (SOM), alkali-hydrolyzed nitrogen (AN), available phosphorus (AP), available potassium (AK), and microbial community structures and functions were measured to investigate the relationships between microbial communities and soil nutrients.Results Different fertilization treatments influenced soil nutrients in soybean fields. Compared with CK, the OCF treatment increased the soil SOM, AN, AP, and AK by 60.67% (P<0.05), 68.09% (P<0.001), 15.18 folds (P<0.001), and 59.54% (P<0.01), respectively, and it also increased soil pH. Amplicon sequencing indicated that different fertilization measures did not alter the community composition of soil microorganisms but changed the relative abundance of different phyla and genera. Compared with CK, the OCF treatment increased the relative abundance of Basidiomycota and Mortierellomycota by 5.62 folds and 4.51%, respectively, while decreasing that of Ascomycota by 38.35%. The OCF treatment reduced fungal community richness and diversity (P<0.05). The alpha diversity analysis revealed that both bacterial and fungal diversity decreased after organic fertilizer application, with fungal alpha diversity showing the most significant reduction (P<0.05). Functional prediction indicated that amino acid metabolism exhibited the highest relative abundance among metabolic pathways in bacterial communities, suggesting that the OCF treatment promoted metabolic processes centered on nitrogen assimilation and protein synthesis, facilitating bacterial participation in soil nutrient transformation. Under the OF treatment, symbiotropic fungi exhibited the highest relative abundance, which suggested that organic fertilizer promoted the ecological functions of fungi in soil nutrient cycling.Conclusion Combined application of organic and inorganic fertilizers modulates soil pH, mitigates soil acidification, and enhances soil nutrient content. Fungal communities exhibit greater sensitivity to organic fertilizer application, which significantly reduces their diversity and stimulates the proliferation of certain pathogenic fungi. Conversely, inorganic fertilizer suppresses the relative abundance of pathogenic fungi. Thus, the combined application of organic and inorganic fertilizers demonstrates distinct advantages in balancing soil nutrient supply with microbial community structure and optimizing soil microbial functional composition. This approach provides theoretical foundations and practical guidance for achieving efficient, green, and sustainable fertilization management in soybean fields.