Complex interactions based on host plant, rhizosphere microorganisms and soil microenvironment are presumed to be responsible for the suppressive properties of biochar against soil-borne diseases, although the underlying mechanisms are not well understood. This study is designed to evaluate the efficacy of biochar amendment for controlling tomato bacterial wilt caused by Ralstonia solanacearum, and to explore the interactions between biochar-induced changes in rhizosphere compound composition, the pathogen and tomato growth. The results showed that biochar amendment decreased disease incidence by 61–78% and simultaneously improved plant growth. The positive ‘biochar effect’ could be associated with enhanced microbial activity and alterations in the rhizosphere organic acid and amino acid composition. Specifically, elevated rhizosphere citric acid and lysine, but reduced salicylic acid, were induced by biochar which improved microbial activity and rendered the rhizosphere unsuitable for the development of R. solanacearum. In addition, nutrients which were either made more available by the stimulated microbial activity or supplied by the biochar could improve plant vigor and potentially enhance tomato resistance to diseases. Our findings highlight that biochar's ability to control tomato bacterial wilt could be associated with the alteration of the rhizosphere organic acid and amino acid composition, however, further research is required to verify these ‘biochar effects’ in field conditions.

基于寄主植物、根际微生物和土壤微环境的复杂相互作用被认为是生物炭对土传疾病的抑制特性的原因，尽管其潜在机制尚不清楚。这项研究的目的是评估对番茄青枯病的生物炭修正疗效引起青枯病，并探讨生物炭引起的根际化合物组成变化、病原体和番茄生长之间的相互作用。结果表明，生物炭改良剂使病害发生率降低了 61-78%，同时改善了植物生长。积极的“生物炭效应”可能与增强的微生物活性以及根际有机酸和氨基酸组成的改变有关。具体而言，生物炭诱导的根际柠檬酸和赖氨酸升高，但水杨酸减少，生物炭提高了微生物活性，使根际不适合青枯菌的生长。此外，通过刺激的微生物活动或生物炭提供的营养物质可以提高植物活力，并有可能增强番茄对疾病的抵抗力。我们的研究结果强调，生物炭控制番茄青枯病的能力可能与根际有机酸和氨基酸组成的改变有关，但是，需要进一步研究以验证这些在田间条件下的“生物炭效应”。