Silicon actively mitigates the negative impacts of soil cadmium contamination on garlic growth, yield, quality and edible safety

•Cd-contaminated garlic poses greatly edible quality and safety concerns worldwide.•Si improved soil acidification and garlic growth, yield and quality.•Si enhanced tolerance mechanisms and reduced Cd-residue of Cd-stressed garlic.•Si application can reduce dietary Cd exposure risks, especially for garlic bulb.