Classification of chemical fertilizers • organic fertilizer and inorganic fertilizer • Sources of Organic fertilizers • Inorganic fertilizers • Nitrogenous fertilizers • Phosphate fertilizers • Potassic fertilizers • Secondary major-nutrient fertilizers • Micronutrient Fertilizers • On the base of physiological effect • On the basis of physical forms • Granular fertilizers

1. Presentation title:
Presented by: Muhammad Ayyan Khan
Classification of
Fertilizers

2. Contents
• Classification of chemical fertilizers
• organic fertilizer and inorganic fertilizer
• Sources of Organic fertilizers
• Inorganic fertilizers
• Nitrogenous fertilizers
• Phosphate fertilizers
• Potassic fertilizers
• Secondary major-nutrient fertilizers
• Micronutrient Fertilizers
• On the base of physiological effect
• On the basis of physical forms
• Granular fertilizers
• To sum up
• Student assignment

3. Classification of chemical fertilizers
✓ Fertilizers can be classified according to their mode of
operation in the soil.
a) Direct fertilizer: are those which contain the nutrient
elements in the form of compounds which are directly
assimilated by plants. For example, superphosphate, nitrates
and ammonium compounds. These contain nutrient elements in
the form of mineral salts which can be absorbed directly.

4. b) Indirect fertilizer: are those substances which are
added to the soil in order to improve its chemical,
mechanical or biological properties. For example,
ground dolomites and limestone used to reduce soil
acidity, and gypsum used to improve the properties of
soils with a high content.
Classification of chemical fertilizers

5. • Chemical fertilizers are classified as; organic fertilizer and
inorganic fertilizer.
• Organic fertilizers
• Organic fertilizers are natural fertilizers obtained from plants and
animals. It enriches the soil with carbonic compounds essential
for plant growth. Organic fertilizers increase the organic matter
content of the soil, promotes the reproduction of microorganisms,
and changes the physical and chemical properties of the soil. It is
considered to be one of the main nutrients for green food.

6. Organic fertilizers can be obtained from the
following products:
•Agricultural Waste
•Livestock Manure
•Industrial Waste
•Municipal Sludge
Sources of Organic fertilizers

7. • Organic fertilizers are classified as natural or
artificial fertilizers;
✓ plant matter, farm yard manure, animal matter etc. are
the examples of natural organic fertilizers,
✓ while waste materials such as waste obtained from
animal excretion. Meat obtained from slaughter houses
consisting of scrap meat, black dry blood, hoofs etc.,
containing 5-10%, nitrogen, phosphorus fertilizers, urea
etc. are examples of artificial organic fertilizers.

8. • Inorganic fertilizers are also classified as natural or
artificial fertilizers;
✓ Chile saltpeter, rock phosphates, potassium salts etc., are
examples of natural inorganic fertilizers.
✓ Artificial inorganic fertilizer: are chemical fertilizers that
contain nutrient elements for the growth of crops made by
chemical means. nitrogenous, phosphate and potassic
fertilizers.

9. ✓ The natural organic and inorganic fertilizers are not sufficient
to make the soil productive as they can no wholly meet the
demand. Hence fertilizer are made artificially.
Fertilizers
Nitrogenous
Fertilizers
Phosphate
Fertilizers
Potassic
Fertilizers
Chemical/inorganic
fertilizers

10. ✓Nitrogenous fertilizers
Nitrogen fertilizers contain nitrogen necessary for the
development of crops. Nitrogen is the main constituent of
chlorophyll that maintains a balance in the process of
photosynthesis. It is also a part of amino acids in plants
and constitutes protein. Nitrogen fertilizers improve the
production and quality of agricultural products.

11. i. Fertilizer containing nitrogen in ammonium (NH4) form
such as ammonium
sulphate, ammonium chloride etc.
ii. Fertilizer containing nitrogen in nitrate (NO3) form such
as calcium nitrate,
sodium nitrate, potassium nitrate etc.
iii. Fertilizer containing nitrogen in amide form such as
urea.

12. ✓ their fertilizing value is expressed as available quantity
of nitrogen in them
✓ Most of nitrogenous fertilizers are synthetic products
obtained by the neutralization of acids with alkalies.
✓ The initial materials used in the manufacture of
nitrogenous fertilizers are sulphuric acid, nitric acid,
carbon dioxide, liquid or gaseous NO3
+, Ca(OH)2 etc.
✓ The nitrogen is contained in the fertilizers either as
NH4
+ cation, as NH2 or as NO3
+ anion forms.

13. nitrogenous fertilizers are divided into
✓ ammonia, nitrate,
✓ ammonium-nitrate and
✓ amide fertilizers.
✓ All nitrogenous fertilizers are soluble in water and well
assimilated by plants, but they are easily carried away
into the deeper layers of the soil during abundant rainfall
or irrigation.

14. ✓Phosphate fertilizers
The efficiency of fertilizer depends upon effective
phosphorus content, methods of fertilizing, properties
of soil and crop strains. Phosphorus found in the
protoplasm of the cell plays an important role in cell
growth and proliferation. The phosphorus fertilizer is
beneficial for the growth of roots of the plants.

15. ✓ Various phosphatic fertilzers depending on their compositions,
have different solubility in soil solutions and are therefore
assimilated by plants differently. According to their solubility
they are classified as waster soluble, available and insoluble.
i. Fertilizers containing water soluble phosphorus such as super-
phosphate, concentrated superphosphate, etc.
ii. Precipitated, calcined phosphate, fused phosphates and basic
slag etc. belong to the group of available fertilizers.

16. iii. Fertilizers containing insoluble phosphate such as rock phosphate,
apatite's, bone flour etc. which are soluble only in strong inorganic
acids
• Fertilizers that supplies potassium such as potassium
chloride, potassium sulphate etc.
• The potassium content of potassic fertilizers is usually
expressed as potassium oxide. K2O referred to as potash.
✓Potassic fertilizers

17. • Potassic minerals, wood ash and sea weeds are natural
potassic fertilizers.
• Muriate of potash (KCl), sulphate of potash (K2SO4) are
examples of processed fertilizers.
• Potassium nitrate (KNO3) and potassium
orthophosphate (KHPO4) are synthetic potassic
fertilizers.

18. a)Potassium chloride (KCl)
✓ Potassium chloride or muriate of potash is a
white or red, crystal containing 60.0 % K2O.
✓ It is completely soluble in water
✓ It is not lost from the soil
✓ It can be applied at sowing or before or after
sowing.

19. b) Potassium sulphate (K2S04)
✓ Potassium sulphate or sulphate of potash is a white salt
and contains 48 % K2O.
✓ It is soluble in water and therefore readily available to the
crop.
✓ It does not produce any acidity or alkalinity in the soil.
✓ It is preferred for fertilization of crops like tobacco,
potato etc.,

20. a) Magnesium fertilizers
✓ These are chemical substances containing the nutrient
magnesium in the form of magnesium cations (Mg2+).
Magnesium Sulphate (MgSO4)
✓ The utilization rate of magnesium fertilizers decreases
with increasing potassium supplies.
Secondary major-nutrient
fertilizers

21. b) Calcium fertilizers
✓ These are the chemical substances containing the nutrient
calcium in absorbable calcium cations ('Ca2+) form. The
raw material of calcium fertilizers is lime found in nature.
Calcium Chloride (CaCl2 6H2O)
✓ It contains at least 15 % Ca. It is highly water soluble and
can, therefore, be dissolved for application as a foliar
nutrient.

22. Micronutrient Fertilizers
a) lron fertilizers
These are generally water soluble substances,
predominantly sprayed as foliar nutrients on the
crops. Plants absorb iron in the form of Fe2+.
Ferrous sulphate (FeSO4 7H2O): It is a water
soluble fertilizer containing 20 % Fe
Fe – Chelates Fe-EDTA Fe-EDDPA: Suitable for
application as foliar nutrients

23. b) Manganese fertilizers
Manganous Sulphate (MnSO4 7H2O): It is the well known
water soluble Mn fertilizer. It is pink salt containing 24 %
Mn. It dissolves in water and is suitable for foliar
application.
Mn – chelates (Mn – DTA): It contains 13 % Mn. It plays
an important role in the crop fertilization.

24. c) Copper fertilize
Copper fertilizers have been used to correct copper
(Cu),deficiencies.
Copper sulphate (CuSO4 5H2O) – 25 % Cu
Copper sulphate (CuSO4 H2O) – 36 % Cu

25. d) Zinc fertilizers:
✓ Zinc (Zn) fertilizers play an important role in Zn deficiency
✓ Zinc sulphate (ZnSO4 7H2O): It is water soluble whitish salt
containing 23 % Zn.
✓ It is applied as foliar nutrient. Its acidic action causes
corrosion damage to plants.
✓ Zinc-oxide (ZnO) : It contains 70 % Zn. It is slightly soluble
in water, it is used as slow acting foliar nutrient

27. Phosphorus sources and fertilizer materials

28. Potassium sources and fertilizer materials

29. Inorganic fertilizers are furthered classified
according to the role they play in soil chemistry, the
number and types of nutrient elements they contain,
their physiochemical properties and in particular, their
solubility in soil water, their physiological effect on
the soil to which the fertilizer has been applied and
method used for manufacturing.

30. Classification on the basis of number of basic nutrient elements
(N, P, K) ;
✓ Simple/straight fertilizers: containing only one nutrient
element
✓ Double or triple fertilizers: containing two or three
elements respectively,
✓ Compound fertilizers: Fertilizers containing more than one
nutrient through chemical bonding. Such as monoammonium
phosphate (MAP), (diammonium phosphate (DAP) etc.

31. ✓ Mixed Fertilizers: Fertilizers prepared through mixing
of different fertilizers. They may be of the following two
types
a) Complete fertilizers: Mixed fertilizer that contains 3
primary nutrients i.e. N, P and K for the growth of plants in
the combined form, so that an additional fertilizers is not
necessary. Guano is an example of complete fertilizers.
These fertilizers are being manufactured artificially.

32. b) Incomplete fertilizers: Mixed fertilizer that
contains any 2 primary nutrients i.e. N and P or, K and
P or, N and K such as ammonium phosphate or
potassium nitrate.
✓ The quantity of nutrients varies in different
fertilizer mixtures, based on which they may be
classified as:
i. Low grade fertilizer mixtures: This category of
mixture contains a total of

33. plant nutrients up to or less than 14 per cent in it.
ii. Medium grade mixtures: contains a total of plant
nutrients between 15 to 24 per cent in it.
iii. High grade mixtures: total nutrient contents range
between 25 to 35 percent
According to their solubility in the moisture or in the soil,
fertilizers can be classified as water soluble or soluble in
soil acid. All nitrogenous, phosphate and potash fertilizers
are soluble in water. However, the phosphate fertilizers
dissolve much slower in water.

34. ✓On the base of physiological effect:
• physiologically acid,
• physiologically alkaline
• physiologically neutral.
✓ On the basis of physical forms:
• Solid (Powder form and granular ones)
• liquid

35. ✓Granular fertilizers:
✓ are less hygroscopic, do not cake during storage
✓ are not subjected to weathering
✓ retained by the soil for a longer time
✓ wide variation in range of particle size and sphericity of
granules.
✓ Products range from semigranular mixed fertilizers to granular
and to urea and ammonium nitrate prillls that have a small size
range and quite spherical.

36. ✓ An ideal granular fertilizer is that which is free of lumps,
made up of homogenous, spherical particles in the size
range of 10-14mesh and capable of maintaining the initial
drilling rate of 1 hr, when exposed in 88% relative humidity
at 70 °F.

37. Nitrogenous straight fertilizer:
• Urea
• Ammonium sulphate
• Ammonium chloride
• Calcium ammonium nitrate (CAN)
Phosphatic straight fertilizer:
• Single super phosphate (SSP)
• Triplesuperphosphate (TSP)
Complex and mixed fertilizers:
• Ammonium phosphate (DAP)
• Nitrophosphate (NP)
• Different blends of NPK fertilizers

38. To sum up
✓ Fertilizers are available in both organic as well as inorganic
forms.
✓ Inorganic fertilizers are classified as nitrogenous, phosphatic
and potassium fertilizers.
✓ They can also be classified as straight, complex and mixed
fertilizers.
✓ Modern granular fertilizers are satisfactory product.

39. Recommended Books:
1. Park., M. The fertilizer industry. Woodhead publishing limited, 2001
2. Pk. Sharam. Industrial chemistry