Fertilization plays a critical role in shaping plant performance, substrate health, and microbial dynamics in soilless cultivation systems. However, the comparative effects of organic, inorganic, and integrated organic-inorganic fertilization on tomato physiology, fruit quality, rhizosphere substrate function, and microbial ecology under organic substrate cultivation remain insufficiently explored. To clarify the combined effects of organic, inorganic, and integrated organic–inorganic fertilization on tomato grown in organic substrate, we compared four treatments: no fertilizer (CK), organic fertilizer (OR), inorganic fertilizer (IN), and a 50%–50% organic–inorganic mix (MIX). We assessed plant morphology and photosynthesis, fruit quality, physicochemical properties and enzyme activities of rhizosphere/non-rhizosphere substrate, and bacterial community structure and function. Compared with CK, MIX significantly increased yield by 159.09% (2.28 ± 0.24 kg·plant⁻¹) and improved vitamin C, soluble sugars, lycopene, and the sugar–acid ratio by 20.77%, 19.49%, 23.65%, and 71.25%, respectively; expression of vitamin C biosynthesis genes GME1 and GGP1 was up-regulated. Microbial analyses showed that MIX increased rhizosphere community diversity, while PICRUSt2 and FAPROTAX prediction indicated a potential enrichment of nutrient-cycling functions, consistent with higher urease and sucrase activities and increased TN/TP/TK contents. Overall, integrated organic–inorganic fertilization was associated with higher yield, improved fruit quality, and a more favorable rhizosphere micro-ecosystem under the present experimental conditions, suggesting that it may represent a sustainable fertilization strategy for tomato grown in organic substrates.
Ma et al. (2026) studied this question.