Effects of different straw biochar combined with microbial inoculants on soil environment in pot experiment

Ginseng is an important cash crop. The long-term continuous cropping of ginseng causes the imbalance of soil environment and the exacerbation of soil-borne diseases, which affects the healthy development of ginseng industry. In this study, ginseng continuous cropping soil was treated with microbial inocula using broad-spectrum biocontrol microbial strain Frankia F1. Wheat straw, rice straw and corn straw were the best carrier materials for microbial inoculum. After treatment with microbial inoculum prepared with corn straw biochar, the soil pH value, organic matter, total nitrogen, available nitrogen, available phosphorus, and available potassium were increased by 11.18%, 55.43%, 33.07%, 26.70%, 16.40%, and 9.10%, the activities of soil urease, catalase and sucrase increased by 52.73%, 16.80% and 43.80%, respectively. A Metagenomics showed that after the application of microbial inoculum prepared with corn straw biochar, soil microbial OTUs, Chao1 index, Shannon index, and Simpson index increased by 19.86%, 16.05%, 28.83%, and 3.16%, respectively. Three classes (Alphaproteobacteria, Gammaproteobacteria and Sphingobacteria) were the dominant bacteria in ginseng soil, and their abundance increased by 7.87%, 9.81% and 1.24%, respectively, after treatment with microbial inoculum with corn straw biochar. Results indicated that the most effective treatment in ginseng soil would be the combined application of corn straw biochar and Frankia F1.

Effects of Different Straw Biochar Combined With Microbial Inoculants on Soil Environment of Ginseng

Ginseng is an important cash crop. The long-term continuous cropping of ginseng causes the imbalance of soil environment and the exacerbation of soil-borne diseases, which affects the healthy development of ginseng industry. In this study, ginseng continuous cropping soil was treated with microbial inocula using broad-spectrum biocontrol microbial strain Frankia F1. Wheat straw, rice straw and corn straw were the best carrier materials for microbial inoculum. After treatment with microbial inoculum prepared with corn stalk biochar, the soil pH value, organic matter, total nitrogen, available nitrogen, available phosphorus, and available potassium were increased by 11.18%, 55.43%, 33.07%, 26.70%, 16.40%, and 9.10%, the activities of soil urease, catalase and sucrase increased by 52.73%, 16.80% and 43.80%, respectively. A Metagenomic showed that after the application of microbial inoculum prepared fromwith corn stalk biochar, soil microbial OTUs, Chao1 index, Shannon index, and Simpson index increased by 19.86%, 16.05%, 28.83%, and 3.16%, respectively. Three classes (Alphaproteobacteria, Gammaproteobacteria and Sphingobacteria) were the dominant bacteria in ginseng soil, and their abundance increased by 7.87%, 9.81% and 1.24%, respectively, after treatment with microbial inoculum (corn stalk biochar). Results indicated that the most effective treatment in ginseng soil ould be the combined application of corn stalk biochar and Frankia F1.

Isolation and characterization of the cellulose-degrading bacteria from Ngoc Linh ginseng soil in Quang Nam province

Ngoc Linh ginseng (Panax vietnamensis Ha et Grushv.) is an endemic species in Vietnam and was discovered at the Ngoc Linh mountain (Kon Tum/Quảng Nam). Investigations showed that the soil with a thick layer of humus was the ideal condition for growth and development of Ngoc Linh ginseng. Therefore research on microbial flora as well as cellulose-degrading bacteria in ginseng soil may elucidate factors contributing to acclimatized cultivation of this ginseng in Vietnam. From the soil sample with cultivated Ngoc Linh ginseng in Quang Nam, five bacteria strains with cellulose-degrading activities were isolated (QN1, QN2, QN3, QN4, QN5 with respectively hydrolyzed CMC halos diameters of 10, 11, 22, 7, 22 mm) with cellulase activities of 1,31; 1,23; 2,99; 0,99; 2,51 U/ml. The combination of 16S rRNA gene sequences and cultured/biochemical characteristics of the bacteria showed that the five bacteria strains was classified to be Pseudomonas sp. QN1; Pseudomonas sp. QN4; Bacillus sp. QN2; Bacillus sp. QN3; Roseomonas sp. QN5.