carences-et-supplémentation

Deficiencies lead to yellowing of the leaves.

Nutrient deficiencies cause diseases and also generate dead leaves that can encourage the appearance of insect pests.

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Guide to identifying pests, deficiencies and diseases
Open this guide to help you diagnose them by clicking this link.

1. Diagnosis

You can use the descriptions below to identify a nutrient deficiency.

If you cannot clearly identify the situation, remember to take good-quality photos and share them on the Community, which will be there to help you.

2. Nitrogen deficiency (nitrates)

Yellowing across the whole leaf

The upper leaves between the older leaves and the young shoots are pale green.

Possible causes:

Drops in temperature can harm the microbial population and therefore reduce the level of assimilable ammonia.
You do not have enough fish in your system to produce ammonia.
You are not feeding your fish enough; try feeding them more frequently and in smaller quantities.
Your fish are not getting enough protein.

3. Iron deficiency

Yellowing on young leaves and yellowing between the veins

This is quite common in aquaponics but can be avoided fairly easily, which is why we recommend adding supplements every 2 weeks in summer and every 4 weeks in winter (3g, equivalent to one teaspoon / tank).

4. Potassium and magnesium deficiency

Yellowing on older leaves and yellowing on the leaf edges, browning, spots

Potassium, calcium and magnesium deficiencies can be difficult to distinguish from one another. When there is excess calcium or magnesium, you will most likely have a potassium deficiency. In addition, if you add shells to increase carbonates, we recommend adding 150g of potassium every 2 weeks in summer and every 4 weeks in winter (usage recommendations for the Family, 3 times less for the City).

5. Calcium deficiency

As mentioned earlier, these elements tend to compete with each other, which is why you must be careful when adding supplements. If you have a very low KH and you have added potassium, you may notice a calcium deficiency. The consequences include pests and black or brown spots on the tips of young leaves or fruits.

Calcium deficiency / apical chlorosis = blossom-end rot

Blossom-end rot is recognizable by a black spot that grows over time on the lower part of the tomato fruit. This is not a disease but a calcium deficiency.

In aquaponics, add 100ml of calcium and 150g of magnesium every 2 weeks in summer and every 4 weeks in winter (usage recommendations for the Family, 3 times less for the City).
In permaculture, avoid fluctuations between severe dryness and high humidity to better ensure the absorption of nutrients including calcium.
Do not rush to remove the affected parts, since the unaffected parts of the ripe fruit remain edible.
Prefer round tomato varieties over elongated varieties.
Apply a thick layer of BRF to retain moisture.
Add a few water stress indicator plants such as basil.
Spray a calcium solution on the leaves at a rate of 5g/L (in permaculture).

Add the supplements

Dilute the components in 2-3 litres of hot water. Stir for 30 seconds. Let it rest for a few minutes.
Do not mix calcium chlorides with ammonium or magnesium sulfate as they may form precipitates.
Shake again before distributing into the fish tanks.