Nutrients in general

For the healthy development of a plant a number of nutrients are indispensable. The following elements are necessary: carbon, hydrogen, oxygen, nitrogen, phosphorus, sulphur, potassium, calcium, magnesium, iron, manganese, copper, zinc, molybdenum, borium and chlorine. Carbon is being absorbed through carbon dioxide. (In carbon dioxide one particle of carbon is attached to two particles of oxygen). Hydrogen and oxygen are mainly absorbed by means of water. (In water two particles of hydrogen are attached to one particle of oxygen). These matters have already been explained.

NITROGEN (N)

Nitrogen together with phosphorus and potassium are the main ingredients in normal fertilisers. All proteins, also the ones in the plant, contain nitrogen. All enzymes (these are matters that regulate the character and speed of the chemical reactions in the plant) are proteins. Especially chlorophyl with which the plant produces sugars (with the help of light, water and carbon dioxide) contain many proteins and therefore a lot of nitrogen. From the previous you might understand why nitrogen is such an important nutrient for the plant. When a plant receives too little it is first shown by the colour. Because so much nitrogen is needed to make chlorophyl, a shortage will be noticed here first. The plant will become ailingly light green. This fading starts first with the older leaves. But when there is insufficient light it is of no use for the plant to make chlorophyl which also gives this light green colour. When this is the cause however, the leaves also tend to “reach out for the light” in their shape. With a nitrogen shortage you don’t see this. Also with a nitrogen shortage the plant becomes more susceptible to mycosis. With too much nitrogen the opposite will happen. The plant becomes unnaturally dark green and the growth stagnates.

PHOSPHORUS (P)

Just like nitrogen, phosphorus is important for protein chemistry of the plant, especially in the regulation processes. A shortage of it is expressed as slow growth and sometimes a purplish colouring of the whole leaf. The chance of a phosphorus shortage is small with the right nutrition. An excess is more likely to occur, especially with substrate cultivation, because phosphorus can accumulate in the root environment. When this happens the plant can’t absorb enough zinc so the symptoms are similar as with a lack of zinc. (see Zn).

POTASSIUM (K)

This nutrient is especially important in the humidity regulation. With a potassium deficiency, symptoms of burning occur. (see page 10). With too much potassium there will be a shortage of calcium and magnesium. (see Ca and Mg). During the flower period the plant requires more potassium.

MAGNESIUM (Mg)

Magnesium is necessary for the production of chlorophyl. With a deficiency the plant will yellow between the veins, initially in the older (strange enough not in the very oldest) leaves. Your “favourite plant” is a true magnesium lover. Too much would make the growth stagnate, but this has never been established with the cultivation.

CALCIUM (Ca)

This nutrient is “built-in” the cell walls and membranes of the plant cells. A shortage might occur in the leaves when the relative humidity is too high (and they cannot evaporate enough water), and with a potassium overdose. With a lack of calcium, the young leaves and new buds die. The plant also becomes very susceptible to mycosis. If the calcium deficiency is being caused by a too high humidity, the entire crop can be ruined in no time through moulding. An overdose of calcium has never been established with this plant.

SULPHUR (S)

The plant uses sulphur to build up proteins. Overdoses or deficiency are unknown in practice.

IRON (Fe)

The plant uses iron in its enzymes. When growing on soil, both overdose and deficiencies are unknown. When growing on rockwool however, an iron deficiency might occur as a consequence of a too high pH. An iron deficiency is easily recognised by the chlorosis of leaf tissue on the growing shoots. Leaves in the shoots have a network of green veins which stand out among the yellow or white tissue between the veins.

MANGANESE (Mn)

The plant also uses this in its enzymes. Deficiencies and overdoses are both unknown when growing on soil. A lack might occur when growing on rockwool because of a too high pH. This is recognised by a yellowing between the veins of the new leaves (but not the very newest).

COPPER (Cu)

Copper deficiencies are extremely rare. Be careful not to confuse this deficiency with the symptoms of over fertilisation.

ZINC (Zn)

Zinc is also used in the enzymes. A zinc deficiency is usually the result of an overdose of phosphorus. The symptoms are chlorosis of tissue between the veins of top shoots starting at the base of the leaf. A radial or horizontal twisting of the leaf blades in the growing shoots is a dead give away.

BORON (B)

The plant needs boron to transport sugars. When there is a deficiency symptoms first appear on the growing shoots which turn brown or grey and die. The shoots may look burnt. A good indication of B deficiency is that after the top shoot dies, actively growing side shoots start to grow but die also.

MOLYBDENUM (Mo)

This nutrient is needed for a few important enzymes in the plant that play a role in the manufacture of nitrogen. Extremely rare, look for another cause.

IMPORTANT!

One of the things you never find in other manuals is the following: We have told you before that the absorption of nutrients is an active process and that plants can, within certain limits, decide what and how much they absorb with their roots. Suppose that a nutrient solution contains nutrient A and nutrient B in equal amounts. The plant grows fine but it happens to use some more of A than of B. After some time the EC has dropped and is adjusted with new nutrients that again contain equal amounts of A and B. But more has been used of A, so after adjusting, the solution contains more of B than of A. If this continues for a while the solution will contain too much of B and too little of A whereas the EC has the right value.

With the EC you determine the concentration of nutrients but not WHICH nutrients. Besides, the plant also expels certain toxins through the roots into the drainage water. For these reasons we strongly advise you not to use the drainage water a second time.