Alleviating Continuous Cropping Obstacles in Celery Using Engineered Biochar: Insights into Chemical and Microbiological Aspects

In the pursuit of environmental sustainability and food security, biochar has emerged as a promising soil conditioner to mitigate continuous cropping obstacles (CCOs). This study explored the use of engineered biochar (WP400) with high adsorption capacity for phenolic acids in celery cultivation. Using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS) for both target and suspect analyses, along with Biolog EcoPlate™ to track the functional diversity of soil bacteria, the study examined chemical and microbiological interactions at varying WP400 application rates. WP400 enhanced celery growth, reduced disease severity, and adsorbed p-coumaric acid (COU), a potential autotoxin. Additionally, other potential allelochemicals, predominantly fatty acid-related, were identified, suggesting a broader role for fatty acids in allelopathy. WP400 also influenced soil bacterial carbon utilization and altered microbial communities. However, higher WP400 doses (0.8% w/w) may not be beneficial for celery growth and reduced bacterial metabolic potential, indicating limitations to its effectiveness. Proper application of WP400 provides a sustainable solution for alleviating continuous cropping issues, promoting both environmental sustainability and agricultural development.