Nutrient antagonism - Which nutrients affect others?

Nutrient antagonism - Which nutrients affect others?

Plant nutrition is a broad topic that comes with many challenges.

As a new gardener starting out, understanding the elements and how plants absorb/consume them is critical for long term success. Most growers, grow after grow, become much better at understanding their plants and their needs.


Below is a list of elements that cause interactions with others if the ratio is not in synergy:


Excess nitrogen, causes the ratios to shift making Calcium & Potassium unavailable


Excess Phosphorus, can lock out important micro-elements, Zinc, copper & Iron


Excess Potassium, will affect how to plant consumes Calcium & Magnesium


Excess Calcium, reduced availability to Nitrogen, Magnesium, Boron & Phosphorus


Excess Magnesium, locks out Calcium & Potassium leads to complete Micro lockout


Excess Iron, completely restricts Phosphorus and completely locks out Manganese


Excess Manganese, quite rare in excess, but locks out Calcium, Copper, Zinc & Iron



Excess Copper, antagonises Iron, Manganese & Phosphorus


Excess Zinc, antagonises Phosphorus, Copper & Iron


Excess Molybdenum, severe Copper deficiency, further locking out Iron & Zinc


Excess Sodium can create lots of problems limiting Potassium


Excess Boron, Locks out Calcium & Potassium


Excess Sulfur, quite rare, limits Nitrogen, Magnesium, Phosphorus & Calcium


Nutrient antagonism is true for all living systems, if something is in excess there will always be restrictions to other elements. 

Each elemental action is followed by another, if the ratio of this sequence is interrupted then nutritional synergy is affected.


Mulder's Chart



Nutrient ratios are usually correct if you buying pre-made nutrients, the manufacturer usually supplies a feed chart with a set of very specific dosages that increase relative to the growth rate of the plant.

In short, I think if you want to have the most success feeding your plants, less is always more. An interesting experiment to try without too much change is just dropping your EC below 2.0, most people are feeding 2.1-2.4 without including run-off maintenance, usually the run off is high 2 and in some cases 3-4 – at this point you should start to understand if you’re going in at 2.1 and your run off is higher, the plant is consuming very little and a now has concentrated near toxic environment in its rhizosphere (root zone), blocking uptake of all nutrients as a result.

Instead of battling with your reservoir or tank, try running lower EC/PPM nutrient strengths of 1.2 - 1.6  if you were previously using anything near 2.0 or above and you might be surprised with the outcome.


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