# Nickel

> Nickel (Ni) is a micronutrient required for urease, the enzyme that breaks down urea; plants need only traces, which most feeds and waters already contain.

- Canonical: https://genetixbay.com/knowledge/glossary/nickel.html
- Also written: Ni, Ni2+, nickel deficiency
- Glossary category: Nutrients · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Nickel is a trace [micronutrient](https://genetixbay.com/knowledge/glossary/micronutrient.md), the most recent element accepted as essential for higher plants (Brown, Welch and Cary, 1987). Its best-known role is as the metal centre of urease, which splits [urea](https://genetixbay.com/knowledge/glossary/urea.md) into ammonia and [carbon dioxide](https://genetixbay.com/knowledge/glossary/co2-enrichment.md). Plants need it in amounts so small that impurities in salts and water usually cover the requirement.

## In practice

[Deficiency](https://genetixbay.com/knowledge/glossary/nutrient-deficiency.md) is very rare in cannabis. Where it has been seen in other crops, it shows as urea accumulating to toxic levels in leaf tips, causing tip [necrosis](https://genetixbay.com/knowledge/glossary/necrosis.md), especially when urea is the nitrogen source. Most hydro recipes do not add nickel deliberately. Excess nickel is toxic and can induce iron or [zinc deficiency](https://genetixbay.com/knowledge/glossary/zinc.md), so supplements are not recommended without a reason.

## Don't confuse with

- **Nutrient burn**: tip necrosis from high [EC](https://genetixbay.com/knowledge/glossary/ec.md), far more common than Ni-related urea burn.
- **Nickel-plated fittings**: a possible contamination source rather than a feed.

## Related terms

[Micronutrient](https://genetixbay.com/knowledge/glossary/micronutrient.md), [Urea](https://genetixbay.com/knowledge/glossary/urea.md), [Nitrogen](https://genetixbay.com/knowledge/glossary/nitrogen.md), [Nutrient toxicity](https://genetixbay.com/knowledge/glossary/nutrient-toxicity.md)

## Read more

- [Nickel (Ni) in cannabis: essential, needed in traces, almost never worth adding](https://genetixbay.com/knowledge/nutrients/nickel.md)

## Sources

1. Brown PH, Welch RM, Cary EE. 1987. Nickel: a micronutrient essential for higher plants. Plant Physiology 85(3):801-803. https://doi.org/10.1104/pp.85.3.801
2. Marschner P (ed.). 2012. Marschner's Mineral Nutrition of Higher Plants, 3rd ed. Academic Press. https://doi.org/10.1016/C2009-0-63043-9