Biochar immobilized plant growth-promoting rhizobacteria enhanced the physicochemical properties, agronomic characters and microbial communities during lettuce seedling

Spent mushroom substrate (SMS) is the by-products of production, which mainly composed disintegrated lignocellulosic biomass, mycelia and some minerals. The huge output lack effective utilization methods make SMS becoming a serious environmental problem. In order to improve application derived biochar (SBC), composted (CSMS), SBC, combined plant growth-promoting rhizobacteria (PGPR, Bacillus subtilis BUABN-01 Arthrobacter pascens BUAYN-122) SBC immobilized PGPR (BCP) were applied in lettuce seedling. Seven treatments used, including (1) CK, commercial control; (2) T1, CSMS based blank (3) T2, T1 with (9:1, v/v); (4) T3, (19:1, (5) T4, (6) T5, BCP (7) T6, v/v). physicochemical properties substrate, agronomic rhizospheric bacterial fungal communities investigated. addition significantly ( p < 0.05) improved total nitrogen available potassium content. 5% (v/v) addiction treatment (T5) represented highest fresh weight aboveground underground, leave number, chlorophyll content leaf anthocyanin content, lowest root malondialdehyde Moreover, high throughput sequencing revealed that immobilization enhanced adaptability PGPR. PGPR, enriched unique biomarkers. co-occurrence network analysis greatly increased complexity microorganisms correlations two other microorganisms. Furthermore, microbial functional prediction indicated nutrient transport This study showed can increase community.