Silicon (Si)

Role in plants

Silicon strengthens cell walls, improves mechanical strength, and enhances resistance to pests, diseases, and abiotic stress.

Deficiency symptoms

• No classic deficiency symptoms
• Reduced stress tolerance
• Weaker plant structure

Toxicity symptoms

• Rare
• Potential reduction in phosphorus or micronutrient availability

Natural sources

• Silicate minerals
• Sand
• Irrigation water

Fertiliser sources

• Potassium silicate
• Sodium silicate
• Stabilised monosilicic acid products

Plant uptake forms

• H₄SiO₄ (monosilicic acid)