When and how to fertilize olive trees?

Olive trees are evergreen fruit trees that are used to growing on rather poor soils; However, when they are grown with the intention of producing a remarkable amount of fruit, either because the family loves them or because we intend to dedicate ourselves to the production and sale of olives, it is interesting to think about fertilizing them. Learning how to fertilize olive trees can be quite simple if we know the most common fertilizers and how to do it.

In this article we are going to tell you everything you need to know to learn how to fertilize olive trees.

Importance of compost


Crop productivity is not defined by the total of nutrients or resources available to plant, but by the scarcest. That is, if the scarcest nutrient in the soil does not increase, it will be the limiting factor when developing the crop. Therefore, it is convenient to know what the limiting nutrient is going to pay with it and improve production. Before adopting any fertilizing strategy, the composition of the soil must be evaluated. It is advisable to carry out an analysis every 4-5 years to evaluate if everything is going correctly. Especially, it is advisable to measure the concentrations of nitrogen, phosphorus and potassium. These are the main macronutrients that the plant must bring in order to grow in good conditions.

There are some authors who reflect that for every 1000 kilograms of harvested olives, the tree uses approximately 25 kg of potassium, 15 kg of phosphorus and 5 kg of nitrogen. It is common to find a large number of olive trees that are settled in soils poor in organic matter. However, it is not inconvenient for them to have a normal reproduction and life. Despite this, if we want to dedicate these olive trees to the production of olives, we must improve the amount of organic matter in the soil. The most normal thing is that we find greater deficiencies in the supply of nitrogen. The use of nitrogen-rich fertilizers is recommended for both seedlings, young olive trees or specimens that are small in size. Thanks to this nitrogen, its growth is favored.

We must consider when applying nitrogen that an excessive amount is discharged can increase the sensitivity to frost and certain diseases that do not interest us with regard to production. We must never exceed 150 kg of nitrogen per hectare of crop. The concentrations of phosphorus and potassium depend on the type of soil where we are cultivating. If the soil is rich in calcium carbonate, it is usually a soil deficient in phosphorus. Phosphorus is important for flowering, ripening and fruit set. If the soil is poor in this element, it is recommended to apply approximately 0.5 kilograms per tree of phosphoric anhydride.

Finally, potassium has a higher fixation if the soil where we are growing the olive trees is clayey. It is important when it comes to absorbing the nutrient and may present, above all, a deficiency of this element in times of drought in rainfed crops. The role of potassium is important to protect the tree against frost and some diseases. Therefore, it is advisable to pay between 1-2 kilograms per tree in the form of potassium oxide.

When to pay them?

work the soil

Olive trees are trees that are growing practically all year round if the weather is good. This climate has to be temperate-warm, with frosts of up to -7ºC and with maximum temperatures of 40ºC , which are those in the Mediterranean region, the place where they come from. In fact, they only stop in winter, because the month of February in the northern hemisphere is when those frosts occur.

Knowing this, at what time is it better to pay them? Okay. These plants flower in spring and bear fruit right after, so it is interesting to start fertilizing in late winter and not stop until late fall .

How to fertilize olive trees

As they are trees whose fruits are edible, we must always try to avoid the use of synthetic (chemical) fertilizers, since even if the safety period is respected and the olives are cleaned well, we can never be sure that we have been 100% released from any remains that may have remained of the product. Therefore, we will use organic fertilizers, that is to say, those that »the earth gives us».

What types of fertilizers are those? Well, there are several, but for the case at hand we are going to tell you two more that will surely be very useful:

  • Guano: they are the organic remains of bats and penguins. It contains nitrogen, phosphorus, potassium, amino acids, microelements, as well as fungi, bacteria and actinomycetes which keep the roots fed and protected. The dose is two or three tablespoons for every seven liters. 
  • Chicken manure or chicken manure:  It is one of the most concentrated that exists. It contains nitrogen, phosphorus, potassium, calcium, magnesium, sodium, soluble salts, and organic matter. The dose is 600 to 700 grams per square meter. If you can get it fresh, let it dry in the sun for a week. 

Tips on how to fertilize olive trees

how to fertilize olive trees and when

One of the most common tips on how to fertilize olive trees is learning to detect nutrient deficiencies . If you are learning how to fertilize olive trees, you should pay attention to the nutritional deficiency of the olive tree. These deficiencies are usually manifested through certain symptoms such as intense green leaves, good fruit ripening and quite extensive production. If you have this situation, your olive trees are in good condition.

On the other hand, if the tree has some nutrient deficiency, it may show exfoliation, more ocher tonalities on the leaf, and vegetative development or poor productivity may be reduced.

If we observe short internodes, small and deformed leaves or rickets in our tree, it is that our olive tree was not fertilized enough and is nitrogen deficient. The lack of phosphorus also has similar symptoms but also shows necrosis at the apex. This necrosis usually appears in the winter or early spring. The leaf has a more brownish yellow color. Potassium deficiency manifests itself in the old parts, becoming weaker more frequently. It also causes vegetative growth retardation.

I hope that with this information you can learn how to fertilize olive trees and learn about nutrient deficiencies.

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