Farkesht technical guide
The types of fertilizer, and how to choose between them
A fertilizer is not one product; it is one decision. This dossier reads fertilizers along three axes — where they come from, what element they deliver and how fast they release it — so the choice ends as a choice, not a guess.
- main fertilizer families
- 3family
- essential mineral elements
- 14element
- release patterns
- 3pattern
Updated: August 20, 2026Farin Kesht Taban Co.
Three routes
Where does it come from?
Organic, mineral and biological fertilizers are three different routes to the same few elements. What differs is the origin, the speed and the side effect — not whether the plant takes the element better from one of them.
Organic fertilizer
Made from the remains of living things. It releases slowly and, at the same time, keeps the soil alive and soft.
- Compost
- Vermicompost
- Animal manure
- Green manure
Mineral fertilizer
Produced chemically or mined. Precise, fast and calculable.
- Straight
- Compound
- Liquid
Biological fertilizer
Living microorganisms that make the element already in the soil available to the plant — an activator, not a fertiliser in itself.
- Nitrogen-fixers
- Phosphate-solubilizers
- Mycorrhizae
The three routes are not rivals; they are complements. A soil starved of organic matter wastes mineral fertilizer, and a biofertilizer without organic matter has nothing to activate.
Primary nutrients
N, P and K: three corners of one balance
The number on the bag — 20-20-20 — is a ratio of exactly these three elements. The plant always wants all three; only the ratio changes with the growth stage.
- Nitrogen
- Phosphorus
- Potassium
Nitrogen — the green-growth engine
Builds leaves and stems. Too much makes the plant soft and pest-prone; too little shows first as yellowing of the older leaves.
Phosphorus — roots and flowers
Drives energy, rooting and flowering. In cold or alkaline soil it moves slowly and must be placed near the roots.
Potassium — fruit and resilience
Raises fruit quality, water regulation and stress tolerance. Near harvest it becomes the deciding element.
The ratio shifts with the growth stage
Three schematic balance shifts; the real number for any field comes from a soil and tissue test.
Vegetative growth
Nitrogen leads while the plant builds chlorophyll and leaf area.
- N · 3
- P · 1
- K · 2
Flowering
Phosphorus steps forward to strengthen roots and flowers.
- N · 1
- P · 3
- K · 2
Fruiting
Potassium becomes decisive so the fruit fills and holds up.
- N · 2
- P · 1
- K · 3
An NPK ratio without a soil test is a guess. Three numbers on a bag answer three questions: what growth, in what soil, at what stage.
Micronutrients
Small doses, decisive effect
Micronutrients may be needed by the gram per hectare, but their absence locks up the whole crop — like a vitamin in the body.
Secondary nutrients
Calcium, magnesium and sulfur — the bridge between the macros and the micros.
- Ca
Calcium
Cell-wall strength; the defence against blossom-end rot in tomato and apple.
- Mg
Magnesium
The heart of chlorophyll; without it, photosynthesis stops.
- S
Sulfur
Builds protein and the flavour of onion and garlic.
The seven essential micronutrients
The chemical symbol is the same in every language; each element's role sits beside it.
- Fe01
Iron
Builds chlorophyll; yellowing of the young leaves gives the deficiency away.
- Zn02
Zinc
Small leaves and stunting; the most common deficiency in calcareous soils.
- Mn03
Manganese
Activates the photosynthesis enzyme.
- Cu04
Copper
Respiration and nitrogen metabolism.
- B05
Boron
Flowering and pollination; its shortage drops the flowers.
- Mo06
Molybdenum
Nitrogen uptake; the plant's least-needed element.
- Cl07
Chlorine
Water regulation and photosynthesis; usually supplied by water.
A micronutrient shortage is usually spotted through leaf symptoms — but by the time symptoms appear, part of the yield is already gone. A leaf test warns before the symptoms do.
Release speed
Immediate or gradual?
The same element, in the same amount, can release over one week or three months. It is the shape of the release curve that makes the decision.
The curves are schematic; a product's real number depends on its coating, and on soil temperature and moisture.
- Quick release
Available within days and gone soon after; right for starting growth or fixing an acute shortage, but prone to leaching.
- Slow release
Releases gradually, in step with soil activity; steady feeding without a sudden spike.
- Controlled release
A coating or inhibitor sets the timing in advance; for high-value, tightly managed crops.
A more expensive fertilizer is not necessarily better. If the plant is at peak demand, use quick release; if the season is long, slow or controlled. The choice follows time, not price.
Forms
Solid, liquid or suspension?
A fertilizer's physical form decides its route to the plant: through the soil, through the leaf, or with the water.
Granular
Broadcast into the soil; the most common form for base fertilizing.
Powder
Soluble in water or mixed with soil; high precision when blending.
Liquid
Ready to use and homogeneous; for fertigation and foliar feeding.
Suspension
Fine particles suspended in liquid; high concentration without settling.
Fully soluble
One hundred per cent soluble; the heart of fertigation and hydroponics.
Coated
A coated granule; controlled release across the season.
Three routes to the plant
Each form has the route it is most natural in.
Through soil and root
Granules and powders; the season's base nutrition.
Through the leaf
Foliar feeding; fast correction of a micronutrient shortage.
With the water
Fertigation; an exact dose at every irrigation.
The leaf does not replace the root. Foliar feeding is a fast rescue, but the main share of nutrition always comes from the soil.
Choosing
Which fertilizer for which stage
The choice does not start with a brand; it starts with the plant's growth stage. This matrix shows which element or route each stage leans on.
| Priority matrix of nutrients against plant growth stages | Nitrogen | Phosphorus | Potassium | Micros | Organic |
|---|---|---|---|---|---|
| Seedling establishment | Not prioritised | Prioritised | Not prioritised | Not prioritised | Prioritised |
| Vegetative growth | Prioritised | Not prioritised | Not prioritised | Prioritised | Prioritised |
| Flowering | Not prioritised | Prioritised | Not prioritised | Prioritised | Not prioritised |
| Fruiting | Not prioritised | Not prioritised | Prioritised | Prioritised | Not prioritised |
| Ripening and harvest | Not prioritised | Not prioritised | Prioritised | Not prioritised | Not prioritised |
| Winter dormancy | Not prioritised | Prioritised | Not prioritised | Not prioritised | Prioritised |
Four steps to a fertilization plan
A fertilization plan is a calculation, not a brochure.
- 01
Soil and tissue test
Measure the real levels of the elements plus soil pH and salinity; without these numbers every plan is a guess.
Results from an accredited laboratory
- 02
Diagnose the need
Weigh each element's deficit and excess against the plant's needs at its current stage.
A shortlist of priority elements
- 03
Choose the formula and form
Pick the NPK ratio, physical form and release pattern to match the stage and the irrigation system.
A set formula and timing
- 04
Apply and monitor
Apply the calculated dose and watch the plant's response through the season so the next round corrects course.
Leaf and yield feedback recorded
This matrix shows priority, not a universal recipe. Two pistachio orchards with different soils need two different plans — otherwise the soil test would be meaningless.
Questions
Common questions about fertilizer
The six questions we hear most often.
Is organic fertilizer better than mineral?
That is the wrong question. Organic keeps the soil alive and mineral delivers the element precisely and fast; in a sound plan the two sit side by side. Soil without organic matter leaches mineral fertilizer, and mineral fertilizer fixes an acute shortage immediately.
What does the number on the bag mean?
The weight ratio of nitrogen, phosphorus and potassium. 20-20-20 means twenty per cent of each; the rest is carrier material and minor elements. Choosing between numbers is choosing a growth stage, not a quality.
What are the signs of over-fertilizing?
Burnt leaf edges, soft watery growth, soil salinity and leaf drop. Excess fertilizer is more dangerous than a shortage because washing it out of the soil takes months.
Is foliar feeding better than soil fertilizer?
Each has its place. Foliar feeding is for a fast micronutrient correction at a critical moment; the main share of nutrition still comes from the soil. The leaf does not replace the root.
Is slow-release fertilizer worth the extra cost?
When the season is long and you lack the labour for several passes, yes. For crops with a short, sudden peak demand, quick release is the more logical choice. The decision follows time, not price.
Do we really need a soil test?
Without it, fertilizing means buying on a guess. A soil test shows pH, salinity and the available elements, and its cost is trivial next to one wrong application.
Want the fertilization plan for your field calculated?
We start with a soil and tissue test; after that, choosing the fertilizer is a simple, defensible decision.