# Mulder's chart

> Mulder's chart is a diagram showing antagonistic and synergistic interactions between plant nutrients, used as a rough guide to which excesses cause which deficiencies.

- Canonical: https://genetixbay.com/knowledge/glossary/mulders-chart.html
- Also written: Mulders chart, Mulder chart, nutrient interaction chart, Mulder's wheel
- Glossary category: Nutrients · Evidence: Supported
- 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"

Mulder's chart is a circular diagram of the mineral nutrients, with lines connecting pairs that interact. One set of lines marks [antagonism](https://genetixbay.com/knowledge/glossary/nutrient-antagonism.md), where an excess of one element reduces another; another marks synergism, where one aids another. It is named after the Dutch agronomist D. Mulder, who compiled such interactions in the mid-twentieth century.

## In practice

Growers use it as a checklist when a [deficiency](https://genetixbay.com/knowledge/glossary/nutrient-deficiency.md) appears despite adequate feeding: if magnesium is low, check whether potassium, calcium or [ammonium](https://genetixbay.com/knowledge/glossary/ammonium.md) is high; if [zinc](https://genetixbay.com/knowledge/glossary/zinc.md) is low, check phosphorus. It is a starting point rather than a law. Many interactions depend on concentration, [pH](https://genetixbay.com/knowledge/glossary/ph.md), medium and crop, and some lines on popular versions are drawn from soil studies with little support in hydro or in cannabis specifically. Reviews such as Fageria and Rietra and colleagues give a more nuanced picture.

## Don't confuse with

- **Nutrient availability chart (pH chart)**: shows availability by pH, not element interactions.
- **Feed chart**: a dosing schedule.

## Related terms

[Nutrient antagonism](https://genetixbay.com/knowledge/glossary/nutrient-antagonism.md), [Nutrient deficiency](https://genetixbay.com/knowledge/glossary/nutrient-deficiency.md), [Nutrient toxicity](https://genetixbay.com/knowledge/glossary/nutrient-toxicity.md), [Potassium](https://genetixbay.com/knowledge/glossary/potassium.md), [Phosphorus](https://genetixbay.com/knowledge/glossary/phosphorus.md)

## Read more

- [Nutrient antagonism and Mulder's chart: what the evidence actually says](https://genetixbay.com/knowledge/nutrients/nutrient-antagonism.md)

## Sources

1. Fageria VD. 2001. Nutrient interactions in crop plants. Journal of Plant Nutrition 24(8):1269-1290. https://doi.org/10.1081/PLN-100106981
2. Rietra RPJJ, Heinen M, Dimkpa CO, Bindraban PS. 2017. Effects of nutrient antagonism and synergism on yield and fertilizer use efficiency. Communications in Soil Science and Plant Analysis 48(16):1895-1920. https://hub.ifdc.org/handle/20.500.14297/2410