Biochar and PGPR amendments influence soil enzyme activities and nutrient concentrations in a eucalyptus seedling plantation

• Published in: Biomass conversion and biorefinery 2021-10, Vol.11 (5), p.1865-1874
• Main Authors: Ren, Han, Lv, Chengqun, Fernández-García, Víctor, Huang, Baoling, Yao, Jiangming, Ding, Wei
• Format: Article
• Language: English
• Subjects: Biological activity; Biotechnology; Electrical resistivity; Energy; Enzyme activity; Enzymes; Eucalyptus; Microorganisms; Nitrogen; Original Article; Plantations; Redundancy; Renewable and Green Energy; Soil chemistry; Soil properties; Soils
• ISSN: 2190-6815; 2190-6823
• DOI: 10.1007/s13399-019-00571-6

PGPR is widely used to improve the capacity of soil nutrient retention, which is closely related to soil microbial activity and enzyme activity. Biochar amendment can alter soil physicochemical properties, such as soil pH and the capacity of water holding. We conducted a study in Guangxi, China, in January 2018 to determine the responses of soil nutrient concentrations and enzyme activities to PGPR and biochar applications in a eucalyptus plantation. Bacillus megatherian strain Du07 was isolated from eucalyptus rhizosphere soil and was confirmed to be a PGPR by partial 16S rDNA sequencing. Biochar applied in our study was made from wheat straw and was used at three application levels (0 t.hm −2 , 20.0 t hm −2 , 40 t.hm −2 ). The following treatments were evaluated: (1) no PGPR and no biochar applied (M0B0), (2) 5 × 10 10  cfu/mL PGPR (MB0), (3) 20.0 t.hm −2 biochar (B20), (4) 5 × 10 10  cfu/mL PGPR plus 20.0 t.hm −2 biochar (MB20), (5) 5 × 10 10  cfu/mL PGPR plus 40.0 t.hm −2 biochar (MB40). In general, separate application of PGPR and biochar may increase soil urease activity, total nitrogen (TN), and total potassium (TK) concentrations, and co-application of PGPR and biochar may increase soil sucrase activity, electrical conductivity (EC), and TK concentration, indicating that the manner of biochar and PGPR application had a significant influence on soil physicochemical properties and enzyme activities except for TK concentration. Redundancy analysis (RDA) showed that soil NO 3 − -N, NH 4 + -N, TK, TP, and SWC were more closely related to soil enzyme activities than other soil physicochemical properties under our experimental conditions.