Soil and Leaf Analysis Guide for Hazelnut Orchards

Why Does Soil Analysis Matter?

Soil analysis is the most reliable way of establishing your hazelnut orchard’s nutritional needs on a scientific basis. Fertilizing without an analysis is guesswork, and it usually ends in either excessive or insufficient fertilizer use.

The advantages of having a soil analysis done:

• Cost savings: Unnecessary fertilizer use is avoided and the annual fertilizer bill can fall by 30-50%
• Correct rates: How much of each nutrient is required is determined scientifically
• Soil protection: The damage over-fertilization does to the soil is prevented
• Higher yield: Deficient nutrients are made up and yield rises
• pH control: Soil acidity is measured and the need for liming is established

Soil Analysis

When Is It Done?

The best periods for soil analysis are:

• First choice: September-October — after harvest, before autumn fertilization
• Second choice: February-March — after winter fertilization, before spring fertilization
• How often: An analysis every 3-4 years is sufficient (soil properties do not change quickly)
• First time: If you have never had an analysis done, you can take a sample in any period

Caution: Do not sample immediately after a fertilizer application or when the soil is very wet. The results may be misleading.

How Is the Sample Taken?

Sampling is the single most important step determining how reliable the results will be. A badly taken sample leads to a wrong fertilizer recommendation.

What you need:

• A stainless steel or plastic spade
• A clean plastic bucket
• A sample bag (plastic bag)
• A label and a pen

Sampling steps:

1. Divide the orchard into zones: Assess areas with different slope, colour or yield separately
2. Choose your points: Take samples from 10-15 different points in each zone (working in a zigzag)
3. Depth: Sample from a depth of 0-30 cm (the hazelnut rooting depth)
4. Mixing: Mix the samples from all points thoroughly in the bucket
5. Sub-sample: Take roughly 1 kg from the mixture and put it in the bag
6. Labelling: Label with orchard name, date, depth and area details

What not to do:

• Sampling with rusty metal tools (iron contamination)
• Sampling from a single point (it is not representative)
• Sampling immediately after a fertilizer application
• Leaving samples in the sun for long periods

Where Do You Send It?

Places where you can have soil samples analysed:

Institution	Cost	Turnaround	Note
Provincial/district agricultural directorate	Free	2-4 weeks	Grower registration required
University laboratories	100-300 TL	1-2 weeks	Detailed analysis
Private laboratories	200-500 TL	3-7 days	Fast results
Fertilizer companies	Free/discounted	1-2 weeks	May steer you towards a fertilizer purchase

Recommendation: The provincial directorate’s free service is both reliable and economical. A fertilizer recommendation is issued along with the results.

Leaf Analysis

Leaf analysis is an important diagnostic tool that complements the soil analysis. Where soil analysis measures the soil’s nutrient supply capacity, leaf analysis shows how much of that nutrient the tree is actually taking up.

When Is It Done?

• Best period: July (the nut development stage)
• Timing: Leaves must be fully developed and the nuts in their growth phase
• Frequency: It can be done every year, but once every 2-3 years is generally enough

Sampling Method

Rules for taking a leaf sample:

1. Which leaves: Take leaves from the middle of the current season’s shoots (not from the tip or the base)
2. How many leaves: Collect a total of 50-100 leaves from different parts of the orchard
3. All four sides: Take leaves from four different aspects of each tree (north, south, east, west)
4. Choosing trees: Sample healthy trees that represent the orchard (avoid diseased or abnormal trees)
5. Storage: Keep the leaves in a paper bag in a cool place
6. Dispatch: Send them to the laboratory as soon as possible (the same day is ideal)

Caution: If a pesticide spray has been applied, wait at least 15 days after spraying before taking a leaf sample.

Reading the Results

pH Value

Soil pH directly affects how available the nutrients are to the plant.

pH Range	Assessment	Action Required
< 5.0	Very acidic	Urgent liming needed (200-300 kg per decare)
5.0 - 5.5	Acidic	Liming recommended (100-200 kg per decare)
5.5 - 7.0	Ideal	No action needed
7.0 - 7.5	Slightly alkaline	Monitoring is enough
> 7.5	Alkaline	Sulfur application or acidifying fertilizers preferred

Organic Matter

Organic matter determines the soil’s water-holding, aeration and nutrient supply capacity.

• Below 1%: Very low — urgent farmyard manure or compost application
• 1-2%: Low — organic fertilizer application recommended
• 2-4%: Adequate — maintaining the current level is enough
• Above 4%: Good — no additional organic fertilizer needed

In hazelnut orchards of the Black Sea region organic matter is generally between 2 and 4%. Leaf fall and natural organic accumulation both contribute.

N-P-K Values

A soil analysis reports the values of the three main nutrients (nitrogen, phosphorus, potassium):

Nitrogen (N):

• Soil nitrogen levels fluctuate, so nitrogen is usually estimated from organic matter
• If organic matter is below 2%, a nitrogen deficiency is likely
• Use the nitrogen rates in our fertilization program as your reference

Phosphorus (P₂O₅):

• < 3 ppm: Very low — a TSP or DAP application is needed
• 3-6 ppm: Low — fertilizer recommended
• 6-15 ppm: Adequate — maintenance rate
• > 15 ppm: High — no additional phosphorus needed

Potassium (K₂O):

• < 100 ppm: Low — a potassium sulfate application is needed
• 100-200 ppm: Medium — maintenance rate
• > 200 ppm: Adequate — no additional potassium needed

Leaf analysis reference values (dry matter):

Element	Low	Adequate	High
Nitrogen (N)	< 2.0%	2.0-2.5%	> 2.5%
Phosphorus (P)	< 0.12%	0.12-0.25%	> 0.25%
Potassium (K)	< 0.8%	0.8-1.5%	> 1.5%
Calcium (Ca)	< 0.8%	0.8-2.0%	> 2.0%
Boron (B)	< 15 ppm	15-50 ppm	> 50 ppm

Conclusion

Soil and leaf analysis together form your hazelnut orchard’s “health report”. Fertilizing without that report is like walking in the dark — you waste inputs and you may well head in the wrong direction.

In summary:

• September-October is the best period for soil analysis
• Take samples from 10-15 different points and mix them
• You can have the analysis done free of charge at your provincial agricultural directorate
• July is the best month for leaf analysis
• Adjust your fertilization program to the results
• Repeat the analysis every 3-4 years

To build a fertilization plan around your analysis results, see our fertilization program guide. For every stage of hazelnut husbandry, review our hazelnut guide.

📚 Hazelnut Research Institute 📚 Gursoy Findik