Micronutrients (also called trace elements or minor nutrients) are mineral elements that plants need in very small quantities but that are nonetheless essential for healthy growth. The key micronutrients are Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Boron (B), Molybdenum (Mo), Chlorine (Cl), and Nickel (Ni). Despite being needed at part-per-million levels, deficiency in any single micronutrient can cause visible growth disorders and yield loss.
Key Facts
- Iron (Fe) is the most commonly deficient micronutrient β causes yellowing of new growth (chlorosis)
- Iron must be in chelated form (EDTA, DTPA, EDDHA) to remain soluble at higher pH
- Manganese and Zinc are required for enzyme function and photosynthesis
- Boron is critical for cell wall formation and pollen viability
- Molybdenum is needed for nitrogen metabolism β deficiency causes cupped or twisted leaves
- Micronutrient deficiencies often appear when pH is outside the 5.5β6.5 optimal range