Synergistic biochar‑Bacillus consortium enhances phosphorus availability, root architecture, and inflorescence development in greenhouse cherry tomato

Mobilizing legacy phosphorus (P) in greenhouse soils offers a strategy to alleviate P limitation and enhance crop productivity. This study applied biochar-Bacillus consortium as a bio-organic soil amendment. By altering the soil bacterial community, it improved P availability and plant P uptake, promoted root and inflorescence development, and ultimately increased cherry tomato yield. Specifically, soil application of biochar-Bacillus consortium (BM) significantly enhanced soil available phosphorus by 10.16%, microbial biomass phosphorus by 174.76%, and alkaline phosphatase activity by 68.52% in the rhizosphere relative to the control (CK). This enhancement in P bioavailability was significantly correlated with shifts in the soil bacterial community. Compared to treatments with biochar alone (B) or Bacillus liquid culture (M) alone, the enhanced P availability promoted plant P uptake and improved root architecture, as reflected by significant increases in root length, surface area, volume, and tip number. In addition, the improvement of inflorescence development was reflected in a substantial increase in the proportion of effective fruit branches, thereby contributing to a significant yield enhancement of 23.53%. Collectively, this work demonstrates that amending soils with a biochar-Bacillus consortium effectively enhances P bioavailability and cherry tomato productivity, thus emphasizing its potential for sustainable intensification in controlled agricultural systems.