Effects of vermicompost on rhizosphere metabolomics and bacterial community structures by the continuous cropping of scallion (Allium ascalonicum L.)
摘要
A field experiment was conducted for 3 years (From 2018 to 2021) to determine the response to the application with vermicompost on alleviating continuous cropping barriers of scallion (Allium ascalonicum L.). The biological characteristics of scallion with XQ (Base fertilizer increased the application of vermicompost) compared X (Base fertilizer without vermicompost), the plant height, blade length, individual weight, transverse diameter of the pseudostem and yield were significantly increased by 9.0 cm, 6.8 cm, 49.0 g, 1.75 mm, and 1720 kg·667 m− 2 (P < 0.01), respectively. Compared with X, soil organic matter increased by 39.70%, and available nitrogen, available phosphorus, and available potassium decreased by 19.46–13.87% in XQ. High-throughput sequencing and metabolomic profile by liquid chromatography-mass spectrometry (LC-MS) was used to analysis the rhizosphere soil after three years of continuous cropping. Illumina-MiSeq sequencing analysis showed that XQ increased the diversity of the bacterial community in rhizosphere soil. Chloroflexi (0.145 ± 0.01) and Gemmatimonadetes (0.03 ± 0.004) in XQ had higher relative abundance than in X (0.113 ± 0.007 and 0.018 ± 0.005, respectively; p < 0.05). Pathway enrichment analysis indicated that galactose and histidine metabolism was the most differentially expressed metabolic pathway. Among the 16 different metabolites, 12 metabolites were negatively correlated with the two metabolic pathways for galactose and histidine. D-raffinose and O-(4,8-dimethylnonanoyl) carnitine had no significant correlation with any of the bacterial family, and the rest of the metabolites were mainly negatively correlated. Our findings indicated that the use of vermicompost could improve bacterial diversity and metabolites in rhizosphere soil of scallion, so as to effectively alleviate continuous cropping obstacle of scallions.