Maize (Zea mays L.) is a globally significant cereal crop, serving as a fundamental source of food, feed, and industrial raw material. This two year field study investigated the effects of different doses of a microbial fertilizer on the yield, yield components, and grain quality traits of three maize hybrids under field conditions in Afyonkarahisar, Türkiye, during the 2021 and 2022 growing seasons.

The experiment was arranged in a split-plot design with three replications, where maize cultivars (P0937, P0573, and Sy Andromeda) were assigned to the main plots and microbial fertilizer doses (0 (control), 5, 10, 15, and 20 L ha⁻¹) to the subplots. number per ear, especially under the 2.0 L ha⁻¹ microbial fertilizer dose (MF₂), whereas Sy Andromeda showed higher protein (9.12%), starch (75.08%), and fiber contents (ADF: 5.29%, NDF: 17.05%).

The MF₂ dose consistently enhanced yield and quality traits across cultivars and years. Climatic variation notably influenced results; increased rainfall and humidity in 2022 improved grain yield, kernel number, and fat and starch accumulation compared to 2021. Genotype-specific responses to microbial fertilizer doses highlight the importance of considering cultivar × environment × input interactions.

These findings emphasize Significant main and interaction effects of year, cultivar, and microbial fertilizer dose were observed on ear morphology, grain yield, thousand kernel weight, and grain quality traits including ash, protein, fat, starch, acid detergent fiber (ADF), and neutral detergent fiber (NDF).

Cultivar P0937 demonstrated superior grain yield (up to 19.57 t ha⁻¹) and kernel the agronomic potential of microbial fertilizers to improve maize productivity and grain quality when applied according to cultivar and environmental conditions. Further research is needed to assess long-term soil health impacts and integration with conventional fertilization strategies.