Role in plants
Molybdenum is essential for nitrate reduction (nitrate reductase) and nitrogen fixation in legumes. It is required in very small amounts.
Deficiency symptoms
- Nitrate accumulation and N-deficiency-like symptoms
- Pale leaves, poor growth
- “Whiptail” in brassicas (classic symptom)
- More common at low pH
Toxicity symptoms
- Rare in plants
- Excess can affect animal nutrition via forage
Natural sources
- Soil minerals (availability increases with pH)
- Organic matter
Fertiliser sources
- Sodium molybdate
- Ammonium molybdate
Plant uptake forms