生物炭与炭基肥对大豆根际土壤细菌和真菌群落的影响

土壤微生物在农田土壤生态系统中发挥重要作用,然而秸秆生物炭与炭基肥处理对微生物群落的影响以及对农田生态环境的意义尚不清楚。以黄淮海平原豆-麦轮作为研究对象,采用荧光定量PCR和Illumina高通量测序技术比较不同施肥方式对土壤细菌和真菌群落的丰度、组成和多样性差异,探究秸秆还田、生物炭以及炭基肥添加对根际土壤微生物群落结构的影响。试验处理包括单施化肥对照(CK)、秸秆全量还田配施化肥处理(CS)、炭基肥处理(BCF)、低量生物炭配施化肥处理(LB)以及高量生物炭配施化肥处理(HB)。结果表明:与对照CK相比,LB、BCF和HB处理显著提高了根际土壤有机碳和速效磷含量;LB、BCF和HB处理对土壤细菌丰度没有显著影响,HB处理显著降低了变形菌门的相对丰度。HB处理的真菌丰度显著高于CK,增加了86.3%,真菌群落Chao1和ACE指数较CK分别显著增加了5.9%和5.8%;与CK和CS相比,LB、HB和BCF处理明显改变了真菌群落结构。冗余分析(RDA)表明,土壤有机碳、总氮和速效钾是改变真菌群落结构的主要驱动因子。综上,研究表明大豆根际真菌群落对生物炭施加的敏感程度高于细菌,且土壤碳和氮含量是影响真菌和细菌群落结构的关键因子。该研究结果可为秸秆资源的合理利用提供理论参考。

Effects of Biochar and Biochar Compound Fertilizer on the Soil Bacterial and Fungal Community in the Soybean Rhizosphere

Soil microorganisms play an important role in field ecosystem,however it is still unclear that how the microbial community and field ecological environment changes in respond to biochar and biochar compound fertilizer amendment.To investigate the effects of biochar and biochar compound fertilizer on the microbial community structure,a field fertilization experiment was conducted under the soybean-wheat rotation in Huang-Huai-Hai Plain.The changes in abundance,composition and diversity of bacterial and fungal communities were evaluated using quantitative real-time PCR(qPCR)and Illumina high-throughput sequencing methods.The treatments contained chemical fertilizer(CK),straw-returning combined with chemical fertilizer(CS),biochar compound fertilizer(BCF),low biochar application combined with chemical fertilizer(LB)and high biochar application combined with chemical fertilizer(HB).Results showed that LB,BCF and HB treatments significantly increased soil organic carbon(SOC)and available phosphorus(AP)when compared with the CK.However,biochar and biochar compound fertilizer treatment had no effect on the abundance of soil bacteria,while HB treatment significantly reduced the relative abundance of Proteobacteria.The abundance of soil fungi in the HB treatment was significantly increased by 86.3%when compared with the CK.The Chao1 and ACE index of fungal community in HB treatment were significantly increased by 5.9%and 5.8%,respectively.The community structures of soil fungi in LB,HB and BCF treatments were well separated from that in CK and CS treatments.Redundancy analysis(RDA)results suggested that SOC,total nitrogen(TN)and available potassium(AK)were the major driving factors for shifting the fungal community structure.Our results indicate that fungal communities in the soybean rhizosphere are more sensitive to biochar than bacteria,and soil carbon and nitrogen contents are the crucial factors for regulating the bacterial and fungal community structures.The research provides a reference for the rational use of straw resource in agriculture.