Fertilization is widely used in managed Moso bamboo (Phyllostachys edulis (Carrière) J.Houz.) forests in subtropical China, but its short-term effects on soil properties and microbiomes remain uncertain. In this study, we conducted a field experiment with four treatments: no fertilization (NF), compound fertilizer (CF), sheep manure organic fertilizer plus compound fertilizer (SOCF), and a biochar-based sheep manure organic fertilizer combined with compound fertilizer (BSOCF). Surface soils samples were collected approximately one year after the initial application, and soil properties were measured together with bacterial and fungal communities using high-throughput sequencing. Results showed that fertilization mainly affected soil chemical properties rather than overall microbial community structure. Compared with CF, BSOCF significantly increased soil pH (4.56 ± 0.10 vs. 4.30 ± 0.05) and resulted in the highest available phosphorus (AP, 6.38 ± 1.10 mg kg⁻¹) and available potassium (AK, 128.16 ± 17.56 mg kg⁻¹) contents. Microbial responses were comparatively limited. Bacterial richness remained stable, fungal alpha diversity showed only a weak increasing trend, and both beta diversity and phylum-level composition changed little among treatments. Variation in treatment-enriched taxa was associated mainly with soil pH and nutrient availability. Overall, the results indicate that biochar-based sheep manure organic fertilizer can improv soil fertility and partially alleviated soil acidity, while causing only limited short-term shifts in the overall microbial community structure. These findings suggest that BSOCF may be a suitable fertilization strategy for enhancing nutrient availability in Moso bamboo forests with relatively low short-term disturbance to soil microbial assemblages.

Bamboo compost is a renewable organic material that can replace peat and enhance plant resistance to insect pests. However, its combined effects on tomato (Solanum lycopersicumL.) growth, defense responses, and underlying molecular mechanisms remain unclear. In this study, bamboo compost was incorporated into growing substrates at varying proportions (5–30%) to assess its impact on tomato seedling growth, physiological and biochemical traits, and the survival of the South American tomato leafminer, Tuta absoluta. Metabolomic and transcriptomic analyses were further integrated to characterize molecular changes associated with enhanced resistance. The results showed that 10% bamboo compost increased plant height and stem diameter by 25.91% and 10.19%, respectively, while higher proportions inhibited seedling growth. All bamboo compost treatments significantly reduced Tuta absoluta. larval survival, with the lowest day-10 survival (16%) observed under BC−20%. Multi-omics analyses identified 1553 and 2591 DEGs and 292 and 591 DAMs in the BC−10% vs. CK and BC−20% vs. CK comparisons, respectively; 290 differentially expressed transcription factor-encoding genes were identified across both comparisons. BC−20% showed broader defense-related transcriptional and metabolic reprogramming, including MAPK and phytohormone signaling, phenylpropanoid and flavonoid biosynthesis, and cutin and wax formation, but with reduced growth. Overall, BC−10% represents a suitable practical addition rate for promoting tomato seedling growth in peat-reduced cultivation substrates.