Explore an in-depth agronomic introduction to plant nutrition. Learn about the essential nutrients crops consume, and the specific role of every mineral on the overall plant growth. Haifa Group’s experts are sharing knowledge. Haifa Group’s experts are sharing knowledge.

1. Plant Nutrition

2. Plant Nutrition
Essential nutrients - mineral nutrients that are crucial
for plant growth
A plant unable to complete its life cycle in the absence of these
mineral elements.
The function of these elements can not be replaceable by another
mineral elements.
These elements are directly involved in plant metabolism.
Elimination of any one of these elements, plants will display
abnormalities of growth,deficiency symptoms, and will not produce
normally.

3. Plant Nutrition
Essential Nutrients - elements an organism must have for survival
18 elements are considered to be essential for plant nutrition.
Plants obtain most essential nutrients from minerals and organic
matter in soil plant.
Iron
Manganese
Boron
Cooper
Molybdeum
Chlorine
Cobalt
Nickel
Macronutrients
Carbon
Hydrogen
oxygen
Nitrogen
Phosphorus
Potassium
Sulfur
Magnesium
Calciun
C
H
O
N
P
K
S
Mg
Ca
Micronutrients
Fe
Mn
B
Cu
Zn
Mo
Ci
Co
NiFrom air and water
From soil and fertilizer

4. Major essential nutrients
Essential nutrients - mineral nutrients that are crucial
for plant growth
1. C, H, O – absorbed as gases. Carbon and Oxygen from
atmospheric fixation in the photosynthetic reaction and
respiration. Hydrogen and Oxygen too, from water hydrolysis.
2. N,P,K,Ca, Mg, S – Macro elements. Absorbed from soil solution.
Needed in high ratio, their concentration in tissue is measured
by percentages.
N,P,K – Major macro elements.
Ca, Mg, S – Secondary macro elements.

5. Major essential nutrients
3. Fe, Mn, Zn, Cu, Mo, B - Micro elements. Absorbed from soil
solution needed in small quantities, their concentration in tissue
is measured in ppm.
4. B – have a very narrow range of efficiency and even slight
increase in concentration will cause damages (0.5 ppm in soil
solution)
5. Cl, Na – “Damaging nutrients”. Regularly existent in sufficient
quantity in soil and in arid areas even in excess.
The plant need small quantities from them and excess will
damage soil structure and plant tissue

6. Major essential nutrients
Leaves and Petioles
Average value (%)NutrientAverage value (%)Nutriet
245Fe4N
150Ai0.55S
115Mn0.52P
46B5.8K
17Cu0.56Mg
43Zn1.5Ca
Mo0.1Na
Roots take up plant-available nutrients as positively or negatively
charged ions from the soil
(source: A & L, Agronomy Handbook, Ankerman & Large Eds.)

7. Plant’s nutrients
Anions (-)Cations (+)
NO3
-
NitrogenNH4
+
Nitrogen
HPO4
2-
H2PO4
-
PhosphorusK
+
Potassium
SO4
2-
SulfurCa
2+
Calcium
H2BO
3-
H2BO3BoronMg
2+
Magnesium
MoO4
2-
HMOO4
-
MolybdenumMn
2+
Manganese
CL
-
ChlorideCu
2+
Copper
Zn
2+
Zinc
Roots take up plant-available nutrients as positively or negatively
charged ions from the soil
Plant-available nutrient forms

8. Plant Nutrition
Supply of sufficient and efficient balanced nutrition is important for
plants optimal growth.
Nutrients availability should follow plant’s requirements.
Nutrients should be available to the plants “Just-on-Time”.
Any deficiency or delay in nutrient availability will result in a
reduction in yield and its quality

9. Liebig's law of the minimum
Yield-limiting presented as “minimum barrel”
The yield potential of a crop is like a barrel with staves of unequal length.
The capacity of the barrel is limited by the length of the shortest stave (in
this case, potassium), and can only be increased by lengthening that stave.
When that stave is lengthened, another one becomes the limiting factor.
CO2etal
K P N Mg Ca
Tranceelements
13
18
CO2etal
Tranceelements
K P N Mg Ca
Tomato yield
Ton/ha

10. Macronutrients
N – P - K

11. Nitrogen
Is a major component of proteins, hormones, chlorophyll, vitamins and
enzymes essential for plant life.
Nitrogen metabolism is a major factor in stem and leaf growth
(vegetative growth).
Excess applied quantity can delay flowering and fruiting.
Deficiencies can reduce yields, cause yellowing of the leaves and stunt
growth.

12. N - Nitrogen
Function – Major ingredient in proteins, cell plasma and genetic
material in plants.
Deficiency – damage to metabolism reactions, retention of growth
and cell elongation.
Two major sources of Nitrogen to plant:
Fast absorption
NO3
+ NH4
+

13. NH4
+
Absorbed by clay particles.
Acidifying the Rizosphare.
Assimilated in roots to sugar and after to amino acids.
In high temp’= less dissolved oxygen = high root respiration, damages
root and foliage.
Preferred by roots in low temperatures.
Might cause Ca and Mg deficiencies.
When prompt correction of deficiencies is required
When root activity is decreased during the reproductive stage

14. NH4
+
pHpH
-
N3
H+
+
-
R-COO-
NH4
+
HOH+
H+
NH4
+ NH4
+
NO3
-
NO3
-
NO3
-
HO

15. Rizosphare pH affected by Ammonium increase
20%
Ammonium
10%
Ammonium
40%
Ammonium

16. NO3-
Aci Does not absorbed by clay particles.
Alkalizes the Rizosphare.
Assimilated in the foliage by photosynthetic sugars.
Preferred in reproduction stages and seed emergence.
Preferred by roots in high temperatures.
Antagonist to Cl-.
Quick absorption by roots

17. Available forms of Nitrogen to plants
NH4
+
Nitrification
* Good aeration
* Available water
* pH close to 7
* High temperature
NO3
-
CO
NH2
NH2
* Good aeration
* Humid soil
* pH close to 7
* temp’ 10-40 c°
(Toxic)
AMID (NH2)
(Urea)
AMMONIUM (NH4
+)
(Ammonium Nitrate)
AMMONIUM (NH4+)
(Ammonium Nitrate)
Ammonification
)NH4+)2
2(NH3)
Ureaz
(NH4)2CO3
HydrolysisCO(NH2)2
+H2O
( NH4
+
NO3
- )
Nitrosomonas Nitrobacter
NO2
-

18. Available forms of Nitrogen to plants
Denitrification
In cases of lack of aeration in soil, Microorganisms dismantle NO3- and
use the oxygen. Nitrite is created and after that N2 evaporate to
atmosphere.
Nitrogen fixation
Pulses can fix atmospheric Nitrogen to organic compounds by two
bacteria's: Isobacter and Rizobium.
Rizobium small-bulb
developed on pulse root

19. Reactions of urea in soil
Soil
Urea
(NH2)2CO + 2H2O (NH4)2CO3
Urease
Water Ammonium Carbonate
Equation 1
Urea Hydrolysis
Equation 2
Equation 3
Ammonium
NH4
+ + OH-
NH3 + H2O
Ammonia WaterHydroxy1
Ammonium
Carbonate
(NH2)2CO3+ 2H+
2NH+
4 + CO2 + H2O
Ammonium Carbon
Dioxide (gas)
Water

20. Nitrogen cycle in nature

21. P-Phosphorus
• Necessary for seed germination, photosynthesis, protein formation
and Almost all aspects of growth and metabolism in plants.
• Essential for flower and fruit formation.
• Low pH (<4) results in phosphate being chemically locked up in
organic soils.
• Phosphorus must be applied close to the plant's roots.
• Deficiency symptoms:
• Purple stems and leaves; maturity and growth are retarded.
• Yields of fruit and flowers are poor
• Premature drop of fruits and flowers may often occur
• Large applications of phosphorus without adequate levels of zinc can
cause a zinc deficiency.

22. Function – Major ingredient in amino acids, appears in high energy
molecules, part of cell membrane and connected to genetic material
in plants.
Deficiency – Retention of growth and cell elongation especially
roots, reduced flowering appearance.
Soil behavior - Low mobility & solubility – connected with iron,
manganese an aluminum as oxide ; with clay minerals replacing OH-;
with Calcium cations at high pH as low solubility salt.
P - Phosphorus
Slow absorption
H2PO4
-

23. Phosphorus forms in soil
Soil solution
(H2PO4 ,HPO4 ,
dissolved organic P)
Inorganic
(adsorbed,
precipitated, minerals)
& Organic
(adsorbed, associated
with humus)
Solubilization and mineralization
Immobilization
Soil phosphorus
P uptake by plants
Available phosphoursPSB
Bacterial biomass P
1- 2-

24. Phosphorus forms in soil
0.0
0.2
0.8
0.6
0.4
1.0
H3PO4
H2PO4
-
HPO4
2- PO4
3-
0 2 4 6 7 10 12 14
pH
FractionalComposition(a)

25. Potassium
Necessary for formation of sugars, starches, carbohydrates,
protein synthesis
Necessary for cell division in roots and other parts of the plant
Helps to adjust water balance, improves stem rigidity and cold
hardiness.
Enhances flavor and color on fruit and vegetable crops.
Increases the oil content of fruits and is important for leafy crops.
Deficiencies result in low yields, mottled, spotted or curled
leaves, scorched or burned look to leaves.

26. Potassium forms in soil
Potassium in soil exists in four pools according to the availability of the K for
uptake by plant roots.
dissolved in the soil water
adsorbed onto particles of clay and organic matter
held within the crystal structure of clay particles.
Exchangeable K, which is determined by routine soil analysis, is the K that
is most readily available for uptake by of potash to the plant are
indicated in the diagram.
Mineral K
10,000-50,000 kg/ha K
RainManuresFertilisersPlant
Leaching
Less readily
available K
1000-2000 kg/ha K
Readily
available K
100-500 kg/ha K
Soil Solution
5-20 kg/ha K

27. Potassium forms in soil
Soil
Solution
Removed in
harvested
produce
Slow Very slowly
Readily
available K
Less readily
available K
Very slowly
available K
Water-soluble
nutrients in
manures and
fertilizers
Some movement
to depth on very
light soils
Crop Uptake Rain
Fast
‘Exchangeable K’

28. Potassium forms in soil
K
help on surface of
clay particles and
soil colloids
K
From weathered
minerals
K
In unweathered
minerals and clays
K
In fertilizer
K
Water soluble
% of total soil K
in these forms
Availability to
plants
Up to 2 Readity
Up to 10 Slowly
90-98 Very slowly

29. Secondary Elements
Mg – Ca - S

30. Sulfur
Is a structural component of amino acids, proteins, vitamins and
enzymes.
Is essential to produce chlorophyll. It imparts flavor to many
vegetables.
Deficiencies show as light green leaves.
Sulfur is readily lost by leaching from soils and should be applied with a
nutrient formula. Some water supplies may contain Sulfur.

31. Magnesium
Is a critical structural component of the chlorophyll molecule.
Is necessary for functioning of plant enzymes to produce
carbohydrates, sugars and fats.
It is used for fruit and nut formation and essential for germination of
seeds.
Deficient plants appear chlorotic, show yellowing between veins of
older leaves; leaves may droop.
Magnesium is leached by watering and must be supplied when
feeding.
It can be applied as a foliar spray to correct deficiencies.

32. Calcium
Activates enzymes, is a structural component of cell walls.
Influences water movement in cells and is necessary for cell growth
and division.
Some plants must have calcium to take up nitrogen and other
minerals. Calcium is easily leached.
Calcium, once deposited in plant tissue, is immobile (non-
translocatable) so there must be a constant supply for growth.
Deficiency causes stunting of new growth in stems, flowers and roots.
Symptoms range from distorted new growth to black spots on leaves
and fruit. Yellow leaf margins may also appear.

33. Micronutrients
Fe - Mn - B - Zn - Cu - Mo

34. Iron
• Necessary for many enzyme functions and as a catalyst for the
synthesis of chlorophyll.
• Essential for the young growing parts of plants.
• Deficiencies are pale leaf color of young leaves followed by yellowing
of leaves and large veins.
• Iron is lost by leaching and is held in the lower portions of the soil
structure.
• Under conditions of high pH (alkaline) iron is rendered unavailable
to plants.
• When soils are alkaline, iron may be abundant but unavailable.
• Applications of an acid nutrient formula containing iron chelates, held
in soluble form, should correct the problem.

35. Manganese
• Involves in enzyme activity for photosynthesis, respiration, and
nitrogen metabolism.
• Deficiency in young leaves may show a network of green veins on a
light green background similar to an iron deficiency.
• In the advanced stages the light green parts become white, and
leaves are dropped.
• Brownish, black, or grayish spots may appear next to the veins. In
neutral or alkaline soils plants often show deficiency symptoms.
• In highly acid soils, manganese may be available to the extent that it
results in toxicity

36. Boron
• Necessary for cell wall formation, membrane integrity, calcium
uptake and may aid in the translocation of sugars.
• Affects at least 16 functions in plants. These functions include
flowering, pollen germination, fruiting, cell division, water
relationships and the movement of hormones.
• Must be available throughout the life of the plant.
• It is not translocate and is easily leached from soils.
• Deficiencies:
• Kill terminal buds leaving a rosette effect on the plant.
Leaves are thick, curled and brittle.
• Fruits, tubers and roots are discolored, cracked and
flecked with brown spots

37. Copper
• Copper is concentrated in roots of plants and plays a part in nitrogen
metabolism.
• A component of several enzymes and may be part of the enzyme
systems that use carbohydrates and proteins.
• Deficiencies cause die back of the shoot tips, and terminal leaves
develop brown spots.
• Copper is bound tightly in organic matter and may be deficient in
highly organic soils.
• It is not readily lost from soil but may often be unavailable.
• Too much copper can cause toxicity.

38. Molybdenum
• A structural component of the enzyme that reduces nitrates to
ammonia
• Without it, the synthesis of proteins is blocked and
plant growth stops
• Root nodule (nitrogen fixing) bacteria also require it
• Seeds may not form completely, and nitrogen deficiency may occur
if plants are lacking molybdenum
• Deficiency signs are pale green leaves with rolled or cupped margins