Cultivating Olive Trees. Soil – Part 1

This post may contain affiliate links to help the reader find relevant products. We get commissions for purchases made through links.

In fact, the soil is an extremely complex, variable, and living medium, which is made from: organic matter, minerals, water, air, and living organisms. Olive trees soil performs many vital functions helping them to grow:

  • food production
  • storage
  • filtration
  • transportation of many materials including water, carbon, and nitrogen

If an olive tree grower maintains a good soil structure it has a positive effect on the tree’s root growth, water, and oxygen accessibility, and soil strength (source). Olive tree growers can improve soil structure and influence both chemical and physical natural soil properties by using the following activities: tillage (i.e. preparation of land for growing olives), fertilization, waste disposal, and industrial pollution (source).

cultivating olive trees soil

The soil characteristics for an olive plantation are very important in terms of vulnerability to erosion and leaking of contaminating elements found in fertilizers and pesticides. The root system of the olive tree is concentrated in the top 20 – 24 inches (50 – 70 cm) of soil although it may grow roots to a depth of more than 40 inches (1 meter) to satisfy its water needs. Therefore, the soil for olive trees must have an optimal texture, structure, and composition to a depth of at least 40 inches (1 meter).

For this reason, the management of olive tree orchards requires systematic soil testing to assess the existence of any nutritional deficiency, excess, or imbalance. Based on soil testing, olive tree growers can plan nutrient supply via fertilization as well as other practices such as tillage, amendment, and correction.

Olive Trees Soil Importance
Olive Trees’ Soil ensures vital functions and may enhance productivity

In this olive tree cultivation part, let’s look into a brief description of the main chemical and physical soil properties.

1.1. Soil texture and structure

It is scientifically proven, that olive trees respond best to soil textures with balanced proportions of sand, silt, and clay. These are three major soil compounds different in their characteristics and respective particle diameter size.

Soil CompoundBenefitsNegatives
ClayHold onto nutrients so the olive tree has the food it needs
High plasticity
Low permeability of water (holds on water, slow to dry)
Root suffocation in wet conditions
Notable tenacity and cohesion in the dry state
Often alkaline
SiltHold onto nutrients better than sandy soils
Better water holding capacity than sandy soils
Easier to work with than clay soils
Low aeration, low permeability, and water stagnation
Mud formation in wet conditions
greater tendency to pulverization in the dry state
SandGood aeration and high permeability of rainwater
Fast mineralization of organic matter
Nutrients and water often leech away, especially with rainfall
Dries out quickly in summer
Often acidic
Table 1. Cons and Pros of key soil types for olive trees

Too sandy soils do not hold nutrients or water very well needed for olive trees. However sandy soils do provide good aeration for olive trees, especially during rainwater and during fertilization to satisfy their mineral requirements.

The soil for olive trees should not contain too much clay to avoid limiting air circulation and prevent soil management problems. However, clay soils have many nutrients but poor drainage which is a must to have for olive trees.

Best Soil for Olive Trees
Best soil for olive trees consists of balanced proportions of sand, silt and clay

The soil particles should aggregate in granules or bits to make the soil porous for olive trees. This can happen when it is a sufficient amount of organic matter and rational olive soil management to prevent compacting and erosion.

Soil is composed of solid particles (mineral and organic matter) of different sizes, usually bound together into groups by organic matter, mineral oxides, and clay particles. Different organic matter content, texture and structure, and cultivation techniques have a great effect on soil density and porosity: any management practice that increases organic matter will increase the granular structure of the soil, increase the pore space, and decrease the soil density (source).

Not sure what type of soil is for olive trees you have?

There are 2 ways to identify the soil. The first one is to do with the soil test and you send soil samples to the nearest accredited laboratory for particle analysis. Second is the DIY method through the hand texturing method.

1.1.1. Soil Structure Amendments

In terms of soil amendments, olive tree orchards with clay soils may not need to add olive tree fertilizer, but they can add compost and product rich in soil microbes to improve organic matter and drainage.

On the other hand, digging in organic matter and adding a 7 to 10 cm (or 3 to 4 inches) layer of mulch (e.g. straw or compost) over the surface of the soil will help overly sandy soils retain moisture.

In all cases, try to improve organic matter for olive trees, by incorporating the compost, materials rich in soil microbes, and carbon-rich sources of fertilizers.

olive trees soil kalamata
The soil in Kalamata, Greece is naturally perfect to thrive for olive trees (in pic – our Oliviada olive tree orchard)

Overall, clay soils may be one of the most challenging to manage but with the right techniques can be improved and more favorable for your olive trees. It’s important to bypass working on the soil when it is wet to reduce the risk of soil compaction. Furthermore, consider using a cover olive during a cool season.

Furthermore, read more how to prepare the soil when planting olive trees.

1.2. Organic Matter

Organic Matter (OM) is a complex combination of organic compounds deriving from living organism (metabolic) wastes and decaying residuals of plants, animals, and microorganisms, at different stages of decomposition.

The OM directly impacts the structure and chemical-physic characteristics of soil in terms of water infiltration and retention, element absorption, particle aggregations, and buffering power, over the nutrient source for the olive tree. The quantity and nature of OM are highly affected by farming practices and climatic conditions.

A very important part of good soil management is to increase the organic content, especially in order to reduce vulnerability to erosion. Olive tree growers can increase it by incorporating incorporate of organic matter such as farm-yard manure, cover crops, pruning and processing residues, and soil tillage.

Organic carbon and total nitrogen are dependent on Organic Matter present in the soil. Organic carbon is the primary source of energy for soil microbes, but these also require nitrogen to multiply and consume this energy.

1.3. Water Content

Water content analysis is important for olive trees since it is more difficult to absorb nutrients at low soil moisture levels, as nutrient contents will be lower.

So soil water analyses for olive trees can be organized into two main groups: analysis of storage properties and analysis of hydraulic properties.

The analysis of storage properties refers to the soil’s ability to absorb and hold water needed for olive trees. Instead, analysis of hydraulic property refers to the soil’s ability to transmit or conduct water.

1.4. Soil pH

Soil pH is one of the most common and important measurements in standard soil analyses for olive trees. The ideal soil pH for olive trees is neutral around 7 pH well-draining soil.

Soil pH is important because it impacts the chemical and physiological processes in the soil, and the availability of nutrients. Availability changes differently with pH levels: aluminum, copper, iron, manganese, and zinc increase when the pH decreases; unlike magnesium which decreases when the pH decreases (source).

Olive Trees Soil pH
Soil pH is an important to measure for olive trees to grow

1.4.1. Soil pH Amendments

Soils with low pH (< ~ 5.6) i.e. acid soils, may contain significant amounts of soluble aluminum which is toxic to the roots of olive trees and other plants. If soil tests reveal too acidic soil, then adding some lime (commonly with ground limestone (calcium carbonate)) can be neutralized and make it more suitable for olive trees.

Alternatively, use sulfur that lowers the soil pH if it is not acidic enough.

Bear in mind different soil additives come in different concentrations, so carefully follow manufacturer instructions to adjust the soil to a specific pH level suitable for olive trees.

INTERESTED IN PREMIUM OLIVE OIL?

GET OLIVIADA OLIVE OIL –
FROM KALAMATA, GREECE!

1.5. Soil Testing

If you are willing to learn more about the soil for your olive trees, the best way is to take a soil sample and send it to a local laboratory or nursery for testing. These organizations will be able to make recommendations based on local knowledge of olive trees soil as to whether the soil needs pH adjustments or additional nutrients.

On another hand, if you just want to test soil pH, use simple pH testing strips that are available online and at many gardening centers.

Read Next

Cultivating Olive Trees: Soil Management – Part 2

Cultivating Olive Trees: Nutrition – Part 3

Are You Looking to Buy an Olive Tree? 

If you are looking to add more potted trees or other plants to your orchard, or if you like to replace a neglected olive tree, the best places to get them are your local nursery or an online nursery.

One of the most reliable and the world's largest online nurseries is Fast Growing Trees. They deliver fast, neat, and healthy plants backed with a 30-day guarantee.

14400 115756114400

Leave a Comment

Your email address will not be published. Required fields are marked *