The fertilization of the olive tree

Fertilization plays an important role in the maintenance of olive trees , is often overlooked, but if managed well can lead to a marked improvement in production, both in terms of quantity and quality. Well-nourished plants, in fertile soil, tend to stay healthy and produce well, which reduces the phenomenon of alternate production.

In this article we are dedicated to fertilization olive trees for organic farming whose principles are valid both for professional farmers, who manage olive groves for profit, and for those who have a tree in the garden.

Let’s find out what the nutrient needs of this beautiful plant are what is the appropriate period fertilize and what are the best fertilizer for the olive tree organic and mineral.

Contents [Ocultar]

  • The nutritional needs of the olive tree

    • Necessary nutrients

    • Soil analysis in the olive grove

  • When and how to fertilize the olive tree

    • Fundus fertilization

    • annual fertilization

  • Organic fertilization of the olive grove

  • Fertilization and grass

    • Practice of green manures

  • Keep animals in the olive grove


The nutritional needs of the olive tree

The olive tree is a plant that benefits soils well endowed with organic matter . A well-structured and humus-rich soil is certainly a fundamental starting point to ensure complete plant nutrition.

The olive tree is a perennial plant, which can live for centuries in the same soil. D due to its physiological culture, the plant eliminates nutrients In addition to growth, some cultural operations such as pruning and harvesting olive trees involve an obvious elimination of material. Particular attention is paid to the so-called macro nutrients (nitrogen, phosphorus and potassium), which are the ones plants need the most. When we talk about fertilization, we generally refer to the estimation of this harvest, the planning a return .

However, in organic farming, the aim is to take care of soil fertility in general, without necessarily focusing on the scientifically calculated specific intake. With good organic fertilization of the entire orchard, nutrients are generally provided in sufficient quantity and quality .

Outraged basic soil conditioners (compost or mature manure) which are usually subject to fertilization in the olive grove, complete the picture with rock flour, wood ash and macerated plants, which will be distributed at different times each year. In addition or as an alternative to compost or manure, manure or other organic pellets are quite practical to use and in any case effective.

Necessary nutrients

But let’s see in detail what are the different mineral elements that are used for the olive tree, and how recognize any symptoms of deficiency to learn how to diagnose any need.

  • Nitrogen – Nitrogen is essential for the vegetative development of each plant because it stimulates photosynthesis and cell multiplication, but it also contributes to flowering and fruiting and makes the plant more resistant to pest attacks. An olive tree with low nitrogen availability is also more sensitive to the phenomenon of production alternation from one year to the next. Normally mature manure contains an average of 0.5%, while compost can contain up to 1%.
  • The game – is the one that is required in less quantity than the other 2 macroelements, but which still plays an important role for fruiting, germination and root development. Normally, by administering the normal soil amendments every year in the olive grove, there is never a lack of phosphorus, unless the soil is particularly acidic, in which case the phosphorus present becomes insoluble.
  • Potassium – A good supply of potassium in the soil helps the plant to better resist certain diseases and temperature changes. Potassium deficiencies in olive trees are rare, recognizable by leaf discolorations and dry edges of older leaves.

Calcium, magnesium and sulfur are also important elements. The calcium contributes, among other things, to the lignification of the shoots and the good consistency of the olives, the magnesium is involved in chlorophyll photosynthesis, and the sulfur it is a constituent of certain amino acids.

There are also many other items like boron, iron, copper, zinc, molybdenum ,… These are micronutrients, required by the olive tree in very small doses, but no less important for this. However, all are generally provided in a balanced way by common organic amendments and natural fertilizers.

Soil analysis in the olive grove

If, despite the supply of nutrients to the plants, there is particular symptoms such as yellowing or general growth retardation a soil analysis It may be useful to check basic parameters such as the pH and the contribution of elements, the latter being very variable over time.

The important thing is correctly take many subsamples from different points of the plot, taken from the first 20 cm of soil, discarding the most superficial layer of undecomposed material. All subsamples should be mixed to make a single sample for a professional lab.

When and how to fertilize the olive tree

There are several periods when it is worth fertilizing the olive grove. In particular, at the time of planting, an important intervention is carried out, called fertilization of the bottom, while afterwards it is worth returning substances and nutrients to the soil at least once a year, it is a labor of typical autumn. .

Fundus fertilization

Before planting the olive trees we will surely have to carry out a basic fertilization, with compost or well-matured manure to distribute on the plowed ground or directly with the earth excavated from the holes, so that it returns indoors well mixed with the soil amendment.

annual fertilization

For the cultivation and production of olive trees fertilization should be administered annually . Ideally, compost, manure and/or granulated manure should be distributed during the autumn period in the projection of the crown of the plant so that they break down, dilute and be intercepted by the underlying roots. If the ground is sloping, it is better to distribute most of it upstream of the plants, then with the rains the distribution will be unified on the other side as well.

organic fertilizers slowly produce nutrients by many soil microorganisms.

Fertilization of organic olive groves

In an environmentally friendly cultivation method, certified or not, no synthetic mineral fertilizers are used such as urea, superphosphate or ammonium nitrate but only mineral products (rock flour) and organic of natural origin (manure from various animals, manure pellets, compost, but also ashes, by-products of animal sacrifice, macerated plants, etc.).

Admittedly, these are good products and capable of providing plants with the nutrients they need, but it is also important to respect the doses. , as excess nitrates in the soil can also come from natural sources. For example, in certified organic production, care must be taken not to exceed 170 kg per hectare per year of nitrogen distributed.

fertilizer to be spread in the olive grove can be purchased, but a part must also come from pruning residues, preferably cut with a bioshredder or grinder, obviously excluding the largest branches that can be used for the chimney. Green waste has value and should not be used for green harvesting, but should be grounded after processing.

Some organic fertilizers for the olive tree:

  • Manure

  • Compost

  • Manure pellets

  • Pollen

  • wood ash

  • rock flour

  • cornunghia

  • nettle macerate

leaf fertilization

The mineral salts are absorbed by the roots of the plant through the water circulating in the soil, so c a prerequisite for its absorption is the sufficient availability of water .

Consequently, during particularly hot and dry summers, it becomes very difficult for the plant to absorb mineral salts, even if they are abundantly present in the soil. In conventional cultivation, this problem can be overcome by foliar fertilization. which is done with soluble fertilizers, but it can also be used in ecological management.

A good organic foliar fertilization for the olive tree can be done, for example, with leonarditis , a fertilizer rich in moist acids, fulvic acids (organic compounds) and trace elements. The doses to be used for the olive tree are indicated on the label of the commercial product purchased.

Food and grazing

The permanent grass spaces between plants is certainly a good method for maintain high nutrient levels in the soil and reduce the risk of erosion on sloping soils . Grass can also be programmed, if it is decided to sow certain species, but in most cases it is completely spontaneous .


The grass limit is represented by the availability of water , because where there is a great drought, the grass competes for the little water with the olive tree, and in any case it is not able to develop well. At least where conditions permit, grazing is a very valid method and should be preferred to the practice of working the spaces between the rows and leaving them bare.

Practice of green manures

Green manure is a type of temporary grass , because the species, especially planted between the rows, are cut, chopped, left to wither for a few days on the surface and finally buried in the first layers of soil. In this way, thanks to their biomass, they provide the organic substance that translates into nutrients and helps the soil to improve its water retention, with great benefit in summer. For green manures, the ideal is to choose mixtures of:

  • Herbs (oats, ryegrass, rye, etc.), which retain the nitrogen which flows into the groundwater, especially during the rainy periods of autumn-winter.
  • legumes (clover, pea, lupine, etc.) which provide nitrogen thanks to their radical symbiosis with nitrogen-fixing bacteria.
  • Brassicaceae (rapeseed and mustard, etc.) which clean unwanted weeds and chase away certain parasites from the soil.

Grasses have a fasciculate root, with many fine roots, legumes have only one primary root, and therefore also the different way of exploring the soil of the roots of these different plants contributes to make the ground softer and more structured .

This typical practice of organic farming is really positive for the olive grove and we can go into more detail in the article devoted to green manures in particular.

Keep animals in the olive grove

A very useful and interesting practice, if we have animals ( sheep, chickens, geese ), is to let them graze inside the olive grove, so that while they graze they keep the grass low, making cutting unnecessary and helping to fertilize it with their manure.

Depending on the environment, the important thing is to be wary of foxes and raptors who like to chase chickens, and to provide fences if necessary.

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