In the cultivation of the olive tree, it is necessary to take into account the nutritional needs that are required for the optimal development of the tree and its fruits. The subscriber of the olive tree acquires great importance in crops where optimal productions are required. The role of each of the elements in the subscriber of the olive tree is the following:

NITROGEN FERTILIZER

It is the most important element in the subscriber of the olive tree . It accelerates the vegetative activity and the development of the plant, increases the assimilation capacity of other elements and influences the production. It is not very stable in the soil, which is why it must be taken into account in the fertilization processes.

PHOSPHORUS FERTILIZATION

It takes part in the biochemical processes of the plant. Accelerates ripening and improves flowering and fruit set . The plant’s response to phosphorus in the olive tree’s fertilizer occurs one year after its fertilization.

MICRONUTRIENTS IN THE OLIVE GROVE

The  Boron  is a trace element of great importance for the subscriber of the olive tree , whose deficiency occurs most often in calcareous soils and dry soils. Olives with boron deficiencies present problems in flowering and fruit set, with a high number of misshapen fruits.

The  iron: the absence of this microelement gives olive chlorosis due to immobilization bicarbonate ion produces this nutrient.

THE IMPORTANCE OF CALCIUM IN THE OLIVE TREE FERTILIZER

It is an element that is given less importance than it does because generally the soils on which olive trees are based are limestone, although this does not mean that the olive tree absorbs the necessary calcium.

NUTRITIONAL DEFICIENCIES AND EXPECTED SYMPTOMS

NITROGEN DEFICIENCY

The lack of this element causes rickets and short internodes. The leaves are small, deformed and sometimes with diffuse chlorosis, some reddish tints may appear later, especially in old leaves.

This is one of the reasons why, sometimes, the ovary does not reach its full development.

PHOSPHORUS DEFICIENCY

Some of the symptoms of phosphorus deficiency in the olive tree are similar to those of nitrogen , especially the poor development of the leaves and other parts of the tree, but without presenting deformations as in the previous case.

Smaller leaves, in which, in the apical part, lighter green areas appear, while the normal or even darker color is maintained in the area near the peduncle.

Small chlorotic spots may appear, especially in late summer and winter.

necrotic areas , mainly on the part of the apex, and almost always marginal; commonly in winter or early spring. Sometimes olive trees are seen with this symptom and there are no leaves with the symptoms described above.

POTASSIUM DEFICIENCY

They tend to manifest themselves in the oldest tissues and parts, producing a weakening of them, because being a very mobile element, it easily migrates from one place to another in the plant, and the older tissues are depleted for the benefit of the younger ones.

Vegetative growth reduction. Leaves are smaller than the normal ones and have a more or less atabacado colored area at the apex; in some cases that area is on the edge but almost always near the apex.

Ever the edges roll up. Normally there is no transition zone between the diseased part and the healthy part.

CALCIUM DEFICIENCY

Intense chlorosis in the leaves in the apical part, the color can vary from greenish-yellow in young leaves to yellow-orange in older ones.

Also on old leaves, necrotic areas and even ragged edges can sometimes be seen.

The root system is poorly developed and when the process is advanced, the terminal parts sometimes acquire a gelatinous consistency.

MAGNESIUM DEFICIENCY IN OLIVE GROVE

Chlorotic areas in the leaves that advance from the apex to the base, the transition from one area to another being gradual, so there is no clear line of separation between the two.

If the deficit situation continues, there may be defoliation in the young twigs, accompanied by necrosis in the terminal parts, as well as a general reduction in plant growth.

SULFUR DEFICIENCY IN THE OLIVE TREE

This element is involved in the formation of chlorophyll in olive leaves. Its lack produces a chlorosis similar to that of nitrogen deficiency.

BORON DEFICIENCY AS A MICRONUTRIENT

The most common symptom on the leaves is the presence in the apical part of a spot that looks like a burn, and even with some necrotic part.

In these leaves the existence of a yellowish area is very characteristic , which is usually between the diseased part and the normal aspect of the leaf.

Sometimes, in addition to some deformations, considerable leaf fall can take place, leading to the formation of what is known as “witch’s brooms.”

When the lack of boron is not very pronounced , the fruiting can be apparently normal, but the formed fruit tends to fall, especially in summer. On a few other occasions, some fruits reach maturity, but they are usually very deformed, which gives rise to what is known as “monkey face.”

When there is excess boron, necrotic areas are observed in the apical part of the leaves, there being no transition between one part of the leaf and another.

Trees strongly affected by excess boron do not produce flowers.

COPPER DEFICIENCY

There is a shortening of the internodes , which can form “rosettes”, sometimes accompanied by abnormal branching.

IRON DEFICIENCY IN THE OLIVE TREE

Very clear symptoms of chlorosis ( iron chlorosis ), more visible in young leaves, which can be accentuated, and in extreme cases, produce necrosis at the edges and tips.

MANGANESE DEFICIENCY

Leaf chlorosis with variable symptoms, sometimes accompanied by necrosis.

ZINC DEFICIENCY

The lack of zinc in the olive tree produces the appearance of yellow spots on the adult leaves and an arrest of the growth of the shoots, with shortening of the internodes, giving rise to the formation of “rosettes” similar to what occurs when there is a deficiency coppermade.

SOURCE: Faustino de Andrés Cantero.

AN EXAMPLE OF OLIVE TREE SUBSCRIBER 

Although the fertilizer units that an olive tree needs can vary depending on the area where we are, when we pull from the bibliography we find some differences. The logical thing would be to start from the extractions made by the olive tree to, at a minimum, re-incorporate them into the earth. This would be the example of nutrient extractions:

Nitrogen (N): 15-20 kg / 1,000 kg of olives

Phosphorus (P2O5): 4-5 kg ​​/ 1,000 kg of olives

Potassium (K2O): 20-25 kg / 1,000 kg of olives

Knowing the average production we have, we can calculate the fertilizer additions that we have to do (regardless of the type of fertilizer it is).

For a production of 8,000 kg / ha, an example of fertigation could be the following:

 Nitrogen (N) : 130 fertilizer units

Phosphorus (P2O5): 35 fertilizer units

Potassium (K2O): 180 fertilizer units

However, depending on the farmer and his way of working, depending on the production (the previous one was for 8,000 kg / ha), the health status of the crop, age and a few other factors, these values ​​may vary. Adjust them as you see.

However, there is also an interesting topic, which is to see how to distribute the application of the fertilizer, since the needs of the olive grove in winter will not be the same as in summer. Let’s see it.

Needs, in fertilizer units (UF / ha) of the olive tree, spread over different months.

This is an example of so many other subscription plans for the olive tree that there may be.

WHAT IF WE HAVE AN OLIVE GROVE IN DRY LAND?

Having an olive grove in dry land changes things a lot with respect to an olive grove in irrigation. The traditional way in which we will apply the fertilizers will be to add them directly to the soil. The ideal is to do it in the root area (the same as the foliar area, to speak generically).

Also, depending on the machinery available, it can be done in a foliar way, using vats and taking advantage of phytosanitary treatments.

However, if we do it by means of centrifugal fertilizers , we can provide phosphorus and potassium in the fall. Although, if we want to add the complete NPK, we hope to apply it together once we have collected, in February. If the harvest is done in autumn, we wait for the periods before the beginning of spring to pay, in order to take advantage of all that rain margin.

OLIVE TREE FERTILIZER RECOMMENDATION (KG / HA) 

Subscriber with NPK 20-8-14 and 0.1 B

• Olive production <1,500 kg / ha: 150 kg / ha
• Olive production between 1,500 and 3,000 kg / ha): 300 kg / ha
• Olive production between 3,000 and 4,500 kg / ha: 400 kg / ha
• Olive production between 4,500 and 6,000 kg / ha: 500 kg / ha
• Olive production> 6,000 kg / ha: 600 kg / ha

[alert style = »yellow»] This nutrient ratio does not have to be exact.

In your usual store you can find other similar shapes, but that are related. For example, it is common to find “special olive” fertilizers that are NPK 20-5-10 with sulfur, calcium or magnesium and, of course, micronutrients. The ratio varies very little, so it is also acceptable. [/ alert]

Approximately, the needs of an adult olive tree in high production are the following:

As you can see, the needs for potassium (K2O) are greater than those for nitrogen, but many times only the 20-5-10 formula is usually provided (for economy and time), leaving the applications of potassium nitrate or other forms of potassium (chlorides) through foliar applications .

In most situations, the total supply of potassium remains insufficient to satisfy the total demand for this element.

For this reason, there is a more modern aspect of technicians who prefer to bet initially (from February-March) to use complexes or blending high in potassium, such as a 15-5-20, let the nitrogen be consumed and later at 2 months, add ammonium sulfate or another form of nitrogen.

With this, we broadly cover potassium needs (in fertilizer + foliar applications) and better manage the use of nitrogen.

The contribution of nitrogen in February, can rarely be usable in the following 2 months, because it is easily leached. Given this, the ideal is to use slow-release forms of nitrogen.

USE OF BIOSTIMULANTS AS A COMPLEMENT TO ROOT FERTILIZATION

Foliar treatments are also usually carried out in the olive grove. Some are for the application of phytosanitary products (coppers and products against repilo) and other insecticides (against prays, olive fly, etc.).

Along with these treatments or other independent ones, biostimulants and supplements rich in potassium are usually applied that seek to complement the fertilizers that have not been applied in irrigation or as background fertilizer.

They look for the following:

• Generally, meet the potassium needs from September (olive fattening)
• Stimulate the production of fatty acids (fat yield)
• Stimulate flowering and fruit set with micronutrients, amino acids, seaweed, etc.

Of all the products, amino acids are the most common, although as we noted in other articles, not all amino acids are the same and produce different effects.