Olive tree

Home Fertilization Guide Olive tree

The olive tree is a tree with reduced soil requirements. It thrives in slightly acidic to alkaline soils and can even tolerate pH 8.5. Its resistance to salinity has some impact on yield. Rainfall plays an important role in its fruitage, especially where the crop is not irrigated. The yields increase in the range from 250mm to 500mm and 600mm of rain, when the soil drains normally. Before flowering and until fruit setting, the olive tree needs water, a condition that is satisfied by the rainfall of the season.

The olive grove loses significant amounts of nutrients every year at harvest. These nutrients must be replenished so that the fertility of the soil is not gradually reduced and consequently the productivity of the olive grove is not reduced.
The type and dose of fertilizer depends on a number of factors:
• The kind and variety
• Age of tree
• Production
• Observed nutrient deficiencies
• Crop development stage
• Soil properties
• Water availability

Fertilizers containing potassium, phosphorus, magnesium and boron should be applied before the rainy season in dry olive groves and incorporated into the soil to a depth of 20-30 cm.

Fertilization at planting:
Based on the soil analysis, phosphorus, potassium and magnesium should be added to the planting pit while nitrogen is best applied after the establishment of the olive trees, even one year after planting.

Proper nitrogen fertilization also has a favorable effect on the phenomenon of biennial bearing, (a year of high production followed by a year of reduced production), reducing its intensity. This phenomenon is probably due to the competition between germination and fruit in the year of high fruitage. Its intensity can be mitigated by:
• Pruning in the year of expected high fruitage
• Fertilization, mainly with nitrogen, to strengthen the new germination
• Irrigation

In irrigated crops, the nitrogen requirements are higher and last longer considering that the fruit takes 6-7 months to ripen, so it is beneficial to apply 2/3 of the total amount of nitrogen and potassium with the basal fertilization.

The use of potassium is necessary especially in the year of increased fruitage. The fruit, leaves and branches (pruning) remove significant amounts of potassium from the soil. The potassium fertilizations eventually favor the differentiation and development of flower buds, improves the size of the fruit and increases its oil content.

Boron is the most important trace element for the olive tree. Its deficiency causes coulure and fruit drop. Its application increases fruit setting, production and oil content of the fruit. For boron sufficiency, we recommend 3 foliar sprays of BoroAgro before and after flowering and after harvest.