Fertilizer: Definition, Types, Advantages, Disadvantages, Uses

Fertilizer is the supplementary material that is given to crops to boost productivity. To provide the necessary plant nutrients in areas with poor soil fertility, farmers utilize natural or artificial materials regularly to enhance crop productivity. The practical goal is to determine how much nutrient material to add. These fertilizers include nitrogen, potassium, and phosphorus, which are crucial elements needed by plants. They also increase the soil’s fertility and its ability to retain water. Urea, anhydrous ammonia, super phosphate superphosphate, potassium sulfate, etc. are some examples of fertilizers.

Fertilizer Definition, Types, Advantages, Disadvantages, Uses
Fertilizer Definition, Types, Advantages, Disadvantages, Uses

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Main Ingredients in Fertilizers

Plant fertilizers mainly contain three ingredients:

  1. Nitrogen: Nitrogen is essential for plant growth, particularly of leaves, since it is a constituent of amino acid and proteins, which must be made to make new cells. It is combined forms commonly as ammonium nitrate, other ammonium salts or nitrates, or as urea, are used in plant fertilizer.
  2. Phosphorus: Phosphorus is used in plant fertilizers in the form of phosphate such as superphosphate or triple phosphate. Similarly, basic slag, the byproduct from steel industry is also used as phosphate fertilizer. The main function of phosphorus is to stimulate early root formation and rapid growth of root. It also helps in the formation of high yielding seeds.
  3. Potassium: Potassium is another main ingredients of fertilizers that are used in the form of potassium sulphate, potassium nitrate, and muriate of potash. Potassium ions helps in flowering. It retain water in the plant cell by osmotic pressure and provides healthy root system to the plant.
Plant Fertilizer
Plant Fertilizer

Essential Qualities of Good Fertilizers

N, P, and K are the essential nutrients for a plant. But every compound of N, P or K cannot be used as fertilizer. A compound containing N, P, or K can act as fertilizer only when it has the following qualities:

  • If they come in contact with moist soil or water, they should dissolve quickly (avoid run-off).
  • It should not be injurious to plants.
  • It should be cheap.
  • It should be free of additives and pollutants
  • It should be able to correct the acidity of the soil.
  • Should be consistent in particle size, with granules that are firm and smooth
  • Spread quickly, ensuring even distribution patterns
  • The compound should be stable so that it may be available for a long time for the growing plant.
  • N, P and K must be present in the compound, in such a form, that they can easily be assimilated by the plants.
  • By rain or water, the compound must be changed into a form which the plants can take up easily.

Types of Fertilizers

Fertilizers are primarily divided into two categories: organic and inorganic fertilizers.

Organic Fertilizers:

Organic fertilisers are all-natural fertilizers made from plants and animals. It improves the soil by supplying carbonic molecules required for plant growth. Organic fertilizers change the physical and chemical composition of the soil, increase the amount of organic matter in the soil, and promote microbial reproduction. It is one of the crucial components for green foods. Moreover, Nitrogen, phosphorus, and potassium (NPK) analyses of organic fertilizers are often lower than those of synthetic fertilizers, but they nourish plants for a much longer duration. As a result, organic fertilizers typically have a more modest effect on plants and lawns. Although it can take a little longer, the reward is a lawn that stays greener for a longer period of time. Agricultural Waste, Municipal Sludge, Industrial Waste, Livestock Manure, etc. are the common sources for the organic fertilizers.

Organic Fertilizer
Organic Fertilizer

Inorganic Fertilizer:

Inorganic fertilizers are those produced chemically using processes that contain nutrients for crop growth. The best-known characteristics of these fertilizers are their quick action and availability in a range of forms, including liquid, pellet, granule, and spike. The following types of inorganic fertilizers are available:

  1. Nitrogen fertilizer: The nitrogen in nitrogen fertilizers is essential for the growth of crops. Nitrogen, a vital component of chlorophyll, aids in maintaining the process’s balance during photosynthesis. It comprises protein and is a component of the amino acids found in plants. Fertilizers containing nitrogen increase the quantity and caliber of agricultural output.
  2. Phosphorus fertilizer: Phosphorus is the main nutrient in phosphorus fertilizers. How effective a fertilizer depends on its effective phosphorus content, fertilization methods, soil properties, and crop strains. Phosphorus is an essential component of cell growth and proliferation which is in the protoplasm of the cell. The phosphorus fertilizer helps the roots of the plants grow.

Types Depending on the Nature of Essential Element

Depending on the nature of essential elements that a fertilizer can supply to the soil, the fertilizer have been classified into the following types:

  1. Nitrogenous fertilizers (N-type fertilizers): Only nitrogen can be provided to the soil or plants by these fertilizers. Examples of nitrogenous fertilizers include ammonium sulfate, calcium ammonium nitrate (CAN), basic calcium nitrate, calcium cyanamide, urea, etc.
  2. Phosphate or Phosphorus fertilizers (P-type fertilizers): These fertilizers provide only phosphorus to the soil. Superphosphate, triple superphosphate, and phosphate slag are examples of phosphate fertilizers.
  3. Potash Fertilizers (K-type fertilizers): Only potassium is provided to the plant by these fertilizers. Each of these fertilizers is present in nature. Examples include potassium chloride, potassium sulfate, and others.
  4. Mixed Fertilizers: Mixed fertilizers can give the plant or soil more than one important element. Mixed fertilizers can be categorized into the following groups according to the type of necessary ingredients they supply:
    1. Nitrogen-Phosphorus fertilizers (NP fertilizers): As the name suggests, these fertilizers provide nitrogen and phosphorus to the plant. Ammonium Dihydrogen phosphate NH4H2PO4, Ammonium Dihydrogen phosphate sulfate example, etc. are examples of it.
    2. Phosphorus-Potassium fertilizers (PK-type fertilizers): PK-type fertilizers provide potassium as well as phosphorus ingredients. For example; the mixture of triple superphosphate and potassium sulfate.
    3. Potassium-nitrogen fertilizers (KN-type fertilizers): These fertilizers supply both potassium and nitrogen to the crops. Example; KNO3
    4. Nitrogen –Phosphorus-Potassium fertilizers (NPK- type fertilizers): These fertilizers are known as complete fertilizers since it contains all three basic ingredients required for good fertilizers. For example; a mixture of ammonium sulfate (N-type), triple super phosphate (P-type), and potassium sulfate (K-type) gives an NPK fertilizer.

What are Synthetic Fertilizer?

Synthetic fertilizers are chemical compounds obtained by artificial methods, which are added to the soil to supply the essential nutrients (i.e. N, P, and K) so that the soil becomes fertile. Synthetic fertilizers increase plant growth quickly but offer little to encourage soil life, enhance soil texture, or increase the long-term fertility of your soil. However, Synthetic fertilizers’ speedy results also have a drawback; if used excessively, they risk burning your plants and lawn.

Comparison between Organic Fertilizer and Synthetic Fertilizer

Organic fertilizersSynthetic fertilizers
The term “organic fertilizers” refers to those that come from the environment or from living creatures.Synthetic fertilizers, often known as inorganic fertilizers, are those synthesized compounds, which tend to have higher nitrogen (N), phosphorus (K), and potassium (P) content.
In most cases, spillage or excessive application won’t be harmful.Lawns can burn if fertilizer is accidentally applied too much or applied in consecutive rows.
Natural-based fertilizer nutrients can fluctuate.  Nutrient amounts are highly accurate.  
Favors a balanced soil ecology.The ecosystem and soil structure are barely affected by synthetic fertilizers.
Enhances water retention by improving soil texture, which is crucial in dry conditions.Due to chemical nitrogen driving excessive microorganism development, which over time depletes soil organic matter, this phenomenon may actually reduce soil fertility.
Leaching and run-off are drastically decreased since nutrients are delivered at a pace that plants can utilize.Synthetic fertilizers provide gardens and grasses with an immediate but temporary release of nutrients, which can promote rapid growth at the price of establishing a strong root system.
Examples: mushroom manure, horse and cow manure, kelp meal, compost, blood meal, and bone meal,Examples: Urea, Superphosphate, ammonium Phosphate, Potassium Sulfate, and so on.

Impacts on the use of excessive chemical fertilizer

The crop yields significantly increase by the use of chemical fertilizers. The runoff water into lakes, rivers, and the sea also contains NO3, NH4+, SO42-, Na+, k+, etc. since chemical fertilizers (nitrogen, phosphate) are soluble in water. The following are some of the main effects due to the over usage of chemical fertilizers:

  • The skin and respiratory systems are poisoned by the fertilizer components.
  • Excessive fertilizer use harms plants and lowers soil fertility.
  • It may result eutrophication since excessive fertilizer produces increased growth of algae and other aquatic plants which may clog of rivers and lakes.
  • Higher level of nitrates in drinking water would result many disease.
  • Excess use of fertilizers change the soil texture.
  • Since the amount of organic matter in the soil decreases with increased chemical fertilizer use, the soil may become more acidic.
  • Denitrification of nitrates into oxides of nitrogen particularly N2O may harm the ozone layer.
  • Large amounts of nitrogen sprayed to farms over time harm the topsoil, lowering agricultural yields.
  • The presence of heavy metals in chemical fertilizers can be problematic. These can harm the kidneys, liver, and lungs as it include lead, mercury, cadmium, and uranium.
  • In general, a number of problems, including major soil deterioration, nitrogen leaching, soil compaction, reduction in soil organic matter, and loss of soil carbon, have been brought on by the overuse of chemical fertilizers.

Advantages of Fertilizer

  • Fertilizers have all nutrients required for plant growth.
  • When plants require an immediate fix to survive, fertilizers are essential to enhancing their health.
  • They quickly affect the crops.
  • Easily decomposes in soil and is soluble in water. As a result, plants may easily absorb them.
  • Enhance crop production to produce more food and feed the big population.
  • It also enhances the metabolism of plants.
  • Easily available in the market.
  • Because of its nutrient-specific nature, we can choose a specific fertilizer to supply a certain nutrient.
  • They are risk-free, dependable, and predictable in nature.

Disadvantages of Fertilizer

  • Expensive
  • Leaching takes place, and the fertilizers end up in the rivers, creating eutrophication.
  • Over usage can damage plants.
  • Gives plants nourishment but does not much to keep soil healthy.
  • Long-term use decreases microbial activity and alters the soil’s pH.
  • There is a chance that excessive fertilizing will harm crops and the entire soil ecology.
  • Many fertilizers are toxic to human as well as plants. These frequently cause skin irritability and respiratory issues, and can transmit dangerous chemicals into our diet, affecting health.
  • Effects on the environment: Fertilizers’ direct and indirect effects on the environment via by contaminating the soil and groundwater, as well as by causing plants to grow quicker than usual.

Uses of Fertilizer

  • To grow sufficient food to feed the world’s population.
  • To supply supplementary nutrients to the plants.
  • To make lawns greener, fertilizers high in nitrogen are employed.
  • To replenish the nutrients lost, fertilizer is added to potted plants.
  • By utilizing organic fertilizer, it is possible to increase the soil’s fertility and texture.
  • To meet the nutritional requirements of plants, gardeners utilize fertilizers.

Moreover, the fertilizer can benefit the plants in the following ways:

  • Fertilizers increase a plant’s insect resistance. They are using less insecticide and herbicide as a result, which leads to healthier crops. Because fewer diseases are present, the crops have a higher aesthetic value.
  • The fertilizers’ nitrogen content encourages plant development, as evidenced by the green color of the plants.
  • The phosphorus found in fertilizers aids in the faster production of seeds and roots in plants.
  • The straws and stalks of the plants are strengthened by the fertilizers’ potassium content.
  • Fertilizers deepen plant roots and boost the ability of plants to hold water.


  • Scherer, Heinrich W.; Mengel, Konrad; Kluge, Günter; Severin, Karl (2009). “Fertilizers, 1. General”. Ullmann’s Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a10_323.pub3
  • Chisholm, Hugh, ed. (1911). “Lawes, Sir John Bennet”. Encyclopædia Britannica (11th ed.). Cambridge University Press.
  • https://en.wikipedia.org/wiki/Fertilizer#cite_note-Ullmann1-1
  • Dittmar, Heinrich; Drach, Manfred; Vosskamp, Ralf; Trenkel, Martin E.; Gutser, Reinhold; Steffens, Günter (2009). “Fertilizers, 2. Types”. Ullmann’s Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH.
  • https://byjus.com/biology/fertilizers/
  • https://thefactfactor.com/facts/pure_science/biology/chemical-fertilizers/2225/

About Author

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Jyoti Bashyal

Jyoti Bashyal, a graduate of the Central Department of Chemistry, is an avid explorer of the molecular realm. Fueled by her fascination with chemical reactions and natural compounds, she navigates her field's complexities with precision and passion. Outside the lab, Jyoti is dedicated to making science accessible to all. She aspires to deepen audiences' understanding of the wonders of various scientific subjects and their impact on the world by sharing them with a wide range of readers through her writing.

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