Effects of Tomicus yunnanensis-damaged Pinus yunnanensis Wood Biochar Pyrolyzed at Different Temperatures on Soil Microbial Community of Lolium perenne

Purpose To explore the effects of Tomicus yunnanensis-damaged Pinus yunnanensis wood biochar pyrolyzed at different temperatures on the diversity of fungi and bacteria communities in Lolium perenne soil, clarifying the feasibility of P. yunnanensis weevil-infested wood biochar in plant cultivation, and providing scientific basis for the utilization of P. yunnanensis weevil-infested wood.

Methods A pot experiment of L. perenne was set up, with soil without adding biochar as the control group (CK), and soil with biochar prepared under the temperature of 300, 500 and 700 ℃ as the experimental groups (recorded as T300, T500 and T700, respectively). After the L. perenne grew for 240 days, the high-throughput sequencing technology was used to sequence the soil samples, and the diversity of soil fungal and bacterial communities in different treatments was analyzed.

Results 1) At the phylum level, the dominant groups of soil fungi were Ascomycota, Basidiomycota, and Mortierellomycota, while the dominant groups of soil bacteria were Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexia, Gemmatimonadetes, and Bacteroidetes, and the relative abundance of each dominant group did not differ significantly among treatments. At the genus level, the proportions of unclassified fungi and bacteria were higher, exceeding 48% and 69%, respectively. 2) After adding biochar, there was a significant change in the composition of soil fungal and bacterial operational taxonomic units, but this change was not reflected at the phylum level. 3) The Chao1, Pielou, Shannon-Weiner, and Simpson indices of the soil fungal community were all CK>T300>T50>T700, and the various diversity indices of the bacterial community were all T300>T500>CK>T700, but there was no significant difference among the four treatments. 4) The similarity in fungal and bacterial community composition between T500 and T700, T300 and CK, were higher.

Conclusion P. yunnanensis weevil-infested wood biochar can be prepared at 300, 500 and 700 ℃, and the adding of this biochar does not have a negative impact on the soil fungal and bacterial community structure and species diversity of L. perenne. Considering the effects of P. yunnanensis weevil-infested wood biochar on the soil microbial community of L. perenne and the cost of biochar preparation, it recommended to prepare this biochar under the conditions of 300 and 500 ℃.