To make a correct olive tree fertilizer, the first thing we need to know are the mineral needs of the olive tree.
It must be clear that the best fertilizer for olive trees will be the one that allows us to provide the most deficient nutrients in the olive tree.
To know the mineral deficiencies of the olive tree, it is usual to perform a foliar analysis of the olive tree.
It is also very useful to know the chemical composition of the soil. A detailed study of the soil helps us choose the best fertilizer for our olive plantation.
The soil analysis allows us to know the deficiencies, facilitates the realization of amendments and makes selective fertilization possible.
Having well-kept olive trees will allow us to obtain larger and more regular crops.
What is the best fertilizer for the olive tree?
It is important to know that the productive limit of the olive grove is marked by the nutrient deficit (Liebig law of the minimum) and until we solve the deficiency, we will not be able to increase our production.
Therefore, to know which is the best fertilizer for the olive tree, we need to know the most deficient nutrients in our particular case.
The correction of deficiencies can be carried out with the application of foliar or ground fertilizers. The results are faster when foliar feeding, being easy to assimilate this way Nitrogen, Phosphorus and Potassium. The three most demanded nutrients by the olive tree.
Keep in mind that the olive tree requires approximately the following fertilizer units per 1,000 kg of olives produced:
Olive tree feed, recommended dose: 20-25kg of Potassium, 15 Kg of Nitrogen and 4-5 kg of Phosphorus.
Amount of fertilizer per olive tree will depend on the composition of the fertilizer used, the size of the olive tree, the deficiencies observed. Generalizing, in traditional dryland olive grove, with 150-200 olive trees/ha, the amount of fertilizer per olive tree can vary from 2 to 4 kg.
For seedlings of young olive trees or small olive trees, NPK nitrogen-rich fertilizers should be applied to favor its growth. On the other hand, in olives in production the needs of Potassium are greater and it is convenient to raise their wealth.
The calcium is another essential nutrient for the olive, in acid soils where the presence of calcium is scarce, it is very appropriate to apply foliar fertilizers and provide limestone amendments to the soil.
The incorporation of organic matter into the soil, through the use of ramon choppers, brushcutters… Improves soil characteristics, favoring medium-long term a better assimilation of nutrients by the olive tree.
Selective olive tree fertilizer
If we have an olive grove with multiple olive varieties, we have surely realized that some varieties are more sensitive to nutritional deficiencies.
It must be taken into account that the vigor of the olive tree and a greater root development allows a better use of the existing resources in the soil by certain olive varieties.
For example, in the acid soils of Arenas de San Pedro the Manzanilla Cacereña variety can show foliar deficiencies in Calcium, Potassium and Phosphorus.
However, Verdial de Badajoz with larger and more vigorous olive trees does not show these deficiencies. On the other hand, Manzanilla Cacereña has a better facility to curdle in deficit areas of Boro if we compare it with other olive varieties.
In the previous example, to make a selective olive tree fertiliser, calcium corrections are applied specifically on the ring of olive trees of the Manzanilla variety.
Olive tree feeding: Nutritional imbalances
As in other aspects of life, in the olive tree feeding, there are times less, it is more.
Thus, for example, the excess nitrogen in the olive tree favors the appearance of pests such as the black scale olive tree and the Glifodes. The imbalances produced by excess nitrogen in the olive tree fertiliser also increase the incidence of Repilo.
In addition, foliar treatments can produce toxicities in the olive tree when waters with high sodium (Na) or Chlorine (Cl) waters are used, both easy to assimilate by the olive.
An excessive application of micronutrients such as boron (B) can produce toxicities and major damage to the olive grove.
When treatments with foliar fertilizer for olive trees are excessively acidic, they can cause burns on olive leaves.
Before applying innovative treatments it is important to put yourself in the hands of professionals and review the recommendations published by the Spanish research centers.
Fertilizers for olive leaf foliage
These are some of the most used fertilizers such as foliar fertilizer for olive trees. It is recommended not to exceed the recommended dose and take into account the warnings when combining different fertilizers and products. For example, it is not good to apply phosphates in combination with the copper oxides used for the repile treatment.
|Nutritional element||Soluble fertilizer (Chemical composition)||Recommended dose|
|Nitrogen (N)||Urea (46% N)||2-3% (1% with potassium fertilizers)|
|Phosphorus (P)||Monoammonium phosphate (12% N + 60% P2O5)||1.25-2% (do not mix with cupric products)|
|Monopotassium phosphate (60% P2O5 + 34% K2O)||1.25-2% (do not mix with cupric products)|
|Potassium (K)||Potassium nitrate KNO3 (13% N + 46% K)||1.5-2.5%|
|Potassium chloride KCl (60% K2O)||1.50-2.5%|
|Potassium sulfate, K2SO4 (50% K2O)||1.50-2.50%|
|Boron (B)||Sodium borate,”borax” (20.8%)||0.5%|
|Iron (Fe)||Foliar fertilizer applications are poorly assimilable and ineffective|
|Zinc (Zn)||Zn-EDTA or Zn-DTPA or other chelating agents||Recommended doses by manufacturer|
|Zn-EDTA with zinc sulfate (ZnSO4)||Recommended doses by manufacturer|
|Magnesium (Mg)||Magnesium sulfate (25% epsomite MgO)||0.5 – 0.7%|
|Magnesium nitrate (11% N + 15.3% MgO)||0.5 – 0.7%|
|Manganese (Mn)||Manganese sulfate (MnSO4)||0.15-0.20%|
|Source of data displayed|
Complex fertilizer for the olive tree
The granulated fertilizer complexes for olive trees are the simplest and most common practice of olive tree feed directly to dry land.
NPK complex fertilizers consist of small balls of minerals of different colors.
These are mixed in the proportion that the manufacturer considers most suitable for the olive tree, resulting in a greater or lesser richness in Nitrogen, Phosphorus, Potassium…
There may be important differences in the price of fertilizer for olive trees.
Keep in mind that Nitrogen is easy to obtain and cheap compared to potassium, phosphorus, boron…
There is also a price difference if the fertilizer contains nitrification inhibitors (highly recommended).
1) Improve the efficiency in the application of Nitrogen.
2) Balance the contribution of ammoniacal and nitric nitrogen.
3) Reduces the loss of nutrients by washing or leaching.
4) Soil acidification is reduced by limiting the effects of nitrification.
It is also important to consider the soil pH when applying the fertilizer. In soils with high ph, fertilizers with sulfur content are usually applied to lower the ph and improve nutrient assimilation. For example, nitrogen is usually applied in the form of ammonium sulfate (NH4)2 SO4.
The special fertilizers for the olive tree usually include between 0.1-0.2% boron to facilitate fruit set.
In the case of the olive tree fertilizer for ground, the best date on the calendar for the olive tree feeding is just before the sprouting begins. However, we must be attentive to weather conditions and take the opportunity to add the fertilizer to the ground when it rains.
Fertirrigation in the olive grove
The advantages of the irrigated olive grove, is that they can provide nutrients during a large period of the year. In addition, fertigation allows greater adaptation to the olive tree’s seasonal needs.
It is common to provide nitrogen-rich NPK fertilizers during the sprouting season and olive flowering.
In the bone hardening stage we increase the dose of potassium, balancing it with Nitrogen.
Once the bone hardened, we apply potassium-rich olive tree fertilizer to favor the formation of the fruit and increase the olive yield.
When to pay the olive trees?
In the case of the covert wallet, the best time to fertilize the olive trees is when the olive tree has left winter rest. It is of little use to pay in January when the olive tree is stopped and we run the risk that the rains of winter and spring, take with them part of the fertilizer.
Fertilize with the moist soil or just before it is going to rain is a good way to prevent fertilizer Nitrogen from degrading when exposed to the sun. Although the rains should not be very abundant, since in this case the water could drag the fertilizer. Ideally, once we add the fertilizer, the roots of the olive tree can begin to consume it as soon as possible.
The olive tree fertilizer in fall or autumn is usually done when the olive trees are very short of potassium or phosphorus. The application must be carried out as soon as the soil moisture allows fertilizer to dissolve. It must be taken into account that the olive tree will enter a vegetative stop when the average temperature drops below 10ºC, so that for the olive tree feed to take effect, we must do so at the beginning of autumn. However, the application of Nitrogen treatments should not be done until the spring a, this is because nitrogen encourages sprouting and tender shoots can end up burned by winter frosts.
We hope you found our publication about the olive tree fertilizer useful, the idea is to complement the article with new publications about the most common olive tree deficiencies, treatments and corrections.
We have translated the information on our website from Spanish to English. Note that some words may have seen their meaning altered during their translation.