FERTILIZERS
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What Are Fertilizers?
Fertilizers are the substances (organic or inorganic
materials containing one or more of the nutrients,
mainly nitrogen, phosphorus, and potassium, and
other essential elements) required for plant growth
and yield.
Fertilizers come in various shapes and forms. The
most typical form is granular fertilizer (powder form),
usually come in a bag / box.
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What Are Fertilizers (cont’d)
Most large-scale crop producers use synthetic
fertilizers to increase their economic gain by more
efficiently supplying their crops with the nutrients
they need.
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Why We Need Fertilizers??
To amend soil fertility
To improve the quality and quantity of food
Due to immediate effect and wide coverage
To increase plant growth and reproduction
To give maximum potential to plant
To make up the deficiency of essential elements
which are required for proper growth of plants.
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Essentials Of A Good Fertilizer
It should not be injurious to plant.
It must be fairly soluble in water so that it thoroughly
mixes with the soil.
It should be cheap.
It must be stable so that it is available for a longer
time to the growing plant.
It should not alter the pH of the soil.
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Nutrients Essential for Plant
Growth
• Sixteen chemical elements are known to be
important to a plant's growth and survival. The
sixteen chemical elements are divided into two main
groups:
1. Non-Mineral Nutrients
2. Mineral Nutrients
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Non-Mineral Nutrients
The Non-Mineral Nutrients are:
• Hydrogen (H)
• Oxygen (O)
• Carbon (C)
These nutrients are found in the air and water.
• In a process called photosynthesis,
plants use energy from the sun to
change carbon dioxide
(CO2 - carbon and oxygen) and water
(H2O- hydrogen and oxygen) into
starches and sugars. These starches and sugars are the
plant's food.
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Non-mineral Nutrients (cont’d)
• Photosynthesis means
"making things with light".
• Since plants get carbon,
hydrogen, and oxygen from
the air and water, there is
little farmers and gardeners
can do to control how much
of these nutrients a plant can
use.
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Mineral Nutrients
• The 13 mineral nutrients, which come from
the soil
The mineral nutrients are divided into two
groups:
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Mineral Nutrients (cont’d)
Macro nutrients which are required by the
plant in relatively large amounts ranging from 5kg to
200kg per acre.
Micro nutrients are required only in small
amounts
– minor or trace elements, ranging from 6g to 200g
or less per acre.
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Macro Nutrients
Macronutrients can be broken into two more groups:
Primary Nutrients
• Nitrogen
• Phosphorus
• Potassium
Secondary Nutrients
• Calcium
• Sulfur
• Magnesium
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Micro Nutrients
Iron (Fe)
Copper (Cu)
Zinc (Zn)
Boron (B)
Molybdenum (Mo)
Manganese (Mn)
Chlorine (Cl)
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Effects Of Component
Functions of nitrogen
• Promotes growth of leaves and stem
• Gives dark green color and improves quality of foliage/leaves
• Necessary to develop cell proteins and chlorophyll
Deficiency symptoms
• Sick, yellow-green color
• Short stems, small leaves, pale colored leaves and flowers
• Slow and dwarfed plant growth
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Nitrogen Deficiency
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Functions Of Phosphorus
Stimulates early formation and growth of roots
Provides for fast and vigorous growth
Stimulates flowering and seed development
Necessary for the enzyme action of many plant processes
Deficiency symptoms
Decrease in growth
Slow maturity
Older leaves are purplish color
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Phosphorus Deficiency
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Functions of Potassium
Used to form carbohydrates and proteins
Formation and transfer of starches, sugars and
oils
Increases disease resistance
Deficiency symptoms
Mottled, spotted, streaked or curled leaves
Scorched, burned, dead leaf tips and margins
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Potassium Deficiency
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Classification Of Fertilizers
Classification of fertilizer often done on the
bases of :
• Fertilizer Phases
• Solubility
• Production & contents
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Fertilizer phases
Solid
Liquid
Gaseous
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Fertilizer phases (cont’d)
Liquid fertilizers are sprayed into the soil or added to
water that is used to water the plants.
Solid fertilizers are often dissolved into a liquid
before they are used.
Anhydrous ammonia is the gaseous form of chemical
fertilizer; it is technically in liquid form but is put
under pressure so that it is released like gas.
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On the basis of Solubility
Soluble Fertilizer:
Dissolve in water and are applied as a liquid solution
Fertigation
• fertilizing through irrigation water
• big advantage
Insoluble Fertilizer:
Includes granular and slow release fertilizers applied
to the growing media. 24
Granular vs. Slow Release
Granular
• relatively inexpensive
• easy to find
Slow Release
• more expensive because it is coated
• more uniform release of nutrients over time period
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Production & contents
• On the basis of the production and contents,
fertilizers are often classified into two types:
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Organic Fertilizers
Organic fertilizers come from plant or animal matter
and contains naturally occurring organic materials,
(e.g. manure, worm castings, compost, seaweed).
• Examples: urea, sludge and animal tankage
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Production & contents (cont’d)
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Chemical fertilizers
• (Also known as inorganic fertilizers or
synthetic fertilizers). Come from sources other
than animals or plants….Chemical products.
• Nitrogenous Fertilizers
• Phosphatic Fertilizers
• Potassium fertilizers
• Mixed Fertilizers
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Nitrogenous Fertilizers
These fertilizers supply nitrogen to the plants or soil.
Nitrogen is required during the early stage of plant
growth for the development of stem and leaves. It is the
main constituent of protein imparts green color to the
leaves and enhances the yield and quality of the plants.
Nitrogen is useful for the healthy growth of garden
plants. Some examples of nitrogen fertilizers are:
• Ammonia
• Urea
• Ammonium sulfate,
• Ammonium nitrate (AN)
• Calcium ammonium nitrate (CAN)
• Ammonium sulfate nitrate (ASN) 30
Phosphatic Fertilizers
These fertilizers provide phosphorus to plants or soil.
The most important water soluble fertilizers:
Super phosphates (calcium super phosphate)
Triple super phosphate(diammonium phosphates).
Phosphorus provides resistance against disease and
helps in the growth of roots and seeds.
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Potassium Fertilizers
These fertilizers supply Potassium to the plants or soil.
Potassium also resists germs and encourages growth of
roots.
It is also required for the formation of starch, sugar and
fibrous material of the plant. They make plant
strong by healthy root
development. They also
help in ripening of seeds,
fruits and cereals.
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Mixed Fertilizers
• Mixed fertilizers contain two or more of the elements
nitrogen, phosphorus, and potassium (NPK), which
are essential for good plant growth and high crop
yields.
Examples are:
Ammonium phosphates
Diammonium phosphate
Nitro phosphates
Potash
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Fertilizer Analysis
All fertilizers are labeled with 3 numbers (i.e.12-3-9 or 10-10-
10)giving the percentage by weight of nitrogen (N), phosphate
(P), and potash (K).These numbers are called the “guaranteed
analysis”.
20-10-20
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Fertilizers Industries In
Pakistan
The fertilizer industries have played a vital role in the
development of both the agriculture and industrial
sectors of economy. At the time of independence of
Pakistan, there was no any fertilizer factory but in 1957,
first fertilizer factory was set up at Faisalabad with a 36
capacity of 25 thousand tons of SSP product.
Fertilizers Industries In Pakistan
(cont’d)
Main four fertilizer industries working in
Pakistan are:
• Fauji Fertilizer Limited
• Pak Arab Fertilizers Limited
• Engro Fertilizer Limited
• Dawood Hercules Chemicals Limited
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ADVANTAGES
&
USES
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Advantages
Organic fertilizers have the following advantages:
1. Releasing nutrients at a slower, more consistent rate,
helping to avoid a boom-and-bust pattern.
2. Helping to retain soil moisture, reducing the stress due
to temporary moisture stress.
3. Improving the soil structure.
4. Helping to prevent topsoil erosion (responsible for
desertfication).
5. Organic fertilizers also have the advantage of avoiding
certain problems associated with the regular heavy use
of artificial fertilizers.
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Advantages
Inorganic fertilizers have the following disadvantages:
1. Rich source of nutrients as compared to organic
fertilizers.
2. We can make desired ratio of nutrients.
3. Costs are lower for if fertilizer is locally available.
4. Release nutrients at higher rate than organic
fertilizers.
5. Chemical fertilizers also enter into the soil more
quickly than organic fertilizers because organic
fertilizers have to wait for fungi and bacteria to
break down the fertilizer. 40
Uses Of Fertilizers
Fertilizers can improve yields in a vegetable
garden or increase flowering in an ornamental
garden.
Natural fertilizers like compost and manure are
used to improve soil texture and fertility.
Nitrogen-rich fertilizer is particularly useful
for greening lawns.
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Disadvantages
Organic fertilizers have the following disadvantages:
1. Dilute source of nutrients as compared to inorganic
fertilizers.
2. Organic fertilizers are more difficult to use than
synthetic fertilizers. Because the nutrients in organic
fertilizers can vary, it is more difficult to determine
how much should be used.
3. Organic fertilizers take longer to break down in the
soil and are much less potent, so if they are not applied
in the right amounts at the right time, your plants may
not get the nutrients they need.
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Disadvantages
Inorganic fertilizers have the following disadvantages:
1. Runoff of synthetic fertilizer can enter the waterways,
causing water to be polluted and to lose oxygen.
2. Over time, chemical fertilizers can degrade the quality of
the soil by building up toxins or leaching away natural
nutrients, making the soil unfit for growing plants.
3. Using too much fertilizer can damage plants by
chemically burning roots and leaves.
4. Harmful for health.
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CONCLUSION
Both types of fertilizers have disadvantages,
but in most cases, fertilizing plants is
necessary to maintain a healthy garden. Plants
often require more nutrients than their soil is
able to provide naturally. If cost and
convenience is a bigger concern, you might
prefer synthetic fertilizers. If you are more
worried about environmental issues and health,
you might want to use organic fertilizers.
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