🧫 FERTILIZERS - USE

Fertilizer use efficiency depends on balanced nutrient supply, product choice, and legal quality controls. This lesson introduces fertilizer use patterns, classification, and regulatory context.

---

LECTURE 20

---

FERTILIZERS - USE AND LEGISLATION

Definition, Classification, Indian Scene, products,

consumption, Legislation

Fertilizers

Fertilizers are the materials either natural or manufactured, containing

nutrients essential for normal growth and development of plants. It may also

be defined that any material or substance intended for use as a nutrient

carrier in soil or crops for boosting crop yields.

In India, the use of artificial fertilizers was first initiated in 1896 when

imported Chilean nitrate was used as a fertilizer. By about 1905 calcium

nitrate, calcium cyanamide, ammonium sulphate, super phosphate and

potassium sulphate were also imported and used.

After the World War I, the Imperial Chemical Industries carried out

valuable field experiments on different crops particularly on rice with

ammonium sulphate during the period 1920-30, which established the

26 (2/2)

general superiority over other nitrogenous fertilizers. The manufacture of

ammonium sulphate in India was first started at Belegolla in Mysore in

1938 on a small scale.

Share of total fertilizer consumption (%) in 12 (2/2) India	Col2
Rice	40.5
Wheat	24.2
Sugarcane	8.7

Later in 1947, its manufacture was started at Alwaye . In 1951, the

Government of India set up fertilizer factory at Sindri for the production of

ammonium sulphate in the public sector. Gradually several factories were

established and use of fertilizers become increasingly popular.

Presently India is the Third producer of N and P fertilizers in the

world.

Classification of fertilizers

The fertilizer materials may be classified in several ways

Based on fertilizer mixture behavior

• Straight or simple nitrogenous, phosphatic or Potassic

fertilizers;

• Complex fertilizers having more than one nutrient in single material

and fertilizers having more than one nutrient in single material

• Fertilizer mixtures home mixed or factory mixed materials.

Based on their chemical reaction and nature

• Acidic, neutral, and basic fertilizers

Based on nutrients present

• Simple fertilizers which contain only one nutrient

(Single carrier)

• Compound fertilizers which contain more than one nutrient

(Multinutrient carrier)

Physical properties of fertilizers:

Physical properties of fertilizers have bearing on bagging storage,

transportation, handling, and application. They are properties include –

hygroscopic nature, free moisture content, particle size, melting point,

solubility, specific gravity, segregation,

granule hardness, angle of response, drillability etc.,

Chemical properties of fertilizers:

Chemical properties include the nature and amount of nutrients

present, associated elements, their chemical reaction, and salt index .

These make a basis for their selection by the cultivators so that they may

achieve highest productivity with least damage to soil fertility and least unit

cost of fertilizers.

INDIAN FERTILIZER SCENE

India is the Third largest producer and consumer of fertilizers in the world.

At present, there are 59 large size fertilizer plants in the country manufacturing

range of fertilizers. The current installed capacity is 12.1 m tonnes per annum

(tpa).

This fertilizer sector is highly subsidized. It relies heavily on imports to

meet domestic demand. Indian Government incurs a total subsidy bill about 14%

of fiscal deficit every year.

The major grades of fertilizers are Nitrogenous (N), Phosphatic (P)

and Potassic (K). N accounts for 71%, P for 22%, and K for 7% of the total

fertilizer consumption. Potassic grade of fertilizer is totally imported and is

not manufactured in India.

Urea (85% of N fertilizer consumption) constitutes 58% of the total

consumption of fertilizers in India. Di-ammonium phosphate (DAP) accounts

for approximately 66% of consumption of phosphatic fertilizers.

The N based fertilizer uses indigenously available feedstock (raw

material) to produce ammonia, which is processed further to make urea.

Rock phosphate and potash, the key raw materials for Phosphatic

and Potassic fertilizers respectively are imported into India, due to lack of

domestic availability.

Before April 1, 1997, the State Governments fixed fertilizer prices at non

remunerative levels. In addition, there were procedural delays in fixing prices

for each crop season, and delays in reimbursing subsidy to the producers.

The reimbursement price fixation is now done by the Central Government,

which may lead to more realistic price levels, and faster disbursements of

subsidies.

27 (3/8)

Consumption of Fertilizer by Nutrients (‘000 tonnes)

Year	N	P O 2 5	K O 2	Total
1951-52	58.7	6.9	-	65.6
1961-62	249.8	60.5	28.0	338.3
1971-72	1798.0	558.2	300.6	2656.8
1981-82	4068.7	1322.3	676.2	6067.2
1991-92	8046.3	3321.2	1360.6	12728.0
1992-93	8426.8	2843.8	883.9	12154.5
1993-94	8788.3	2669.3	908.7	12366.3
1994-95	9507.1	2931.7	1124.8	13563.6
1995-96	9822.8	2897.5	1155.8	13876.2
1996-97	10301.8	2976.8	1029.6	14308.1
1997-98	10901.8	3913.6	1372.5	16187.8
1998-99	11353.8	4112.2	1331.5	16797.5
1999-00	11592.7	4798.3	1678.7	18069.7
2000-01	10861.9	4212.4	1557.1	16631.4

Important Fertilizer Products in India

Col1	Grade (%)	Consumption (1999-2000) ‘000 tonnes
Produced in India	Produced in India	Produced in India
Straight Nitrogenous	Straight Nitrogenous	Straight Nitrogenous
Urea	46 N	20277.66
Ammonium sulphate	20.6 N	638.10
Ammonium chloride	25 N	75.19
Calcium ammonium nitrate	25 N	347.25
Straight Phosphatic	Straight Phosphatic	Straight Phosphatic
Single super phosphate	16 P2O5	3600.99
Diammonium phosphate	18-46-0	6937.68
NP/NPK Complex FertilizersN: P2O5: K2O	NP/NPK Complex FertilizersN: P2O5: K2O	NP/NPK Complex FertilizersN: P2O5: K2O
Ammonium Phosphate Sulphate	16-20-0	220.89
Nitro Phosphate with Potash	15-15-15	341.82
Urea Ammonium Phosphate 27 (4/	28-28-0 8)	173.66
Urea Ammonium Phosphate 27 (4/	14-35-14	184.32
Nitro Phosphate	20-20-0	1531.56
Nitro Phosphate	23-23-0	222.19
Others	10-26-26	529.79
Others	12-32-16	499.45
Others	17-17-17	681.00
Others	19-19-19	126.63

Col1	14-28-14	11.47
Imported Fertilizers	Imported Fertilizers	Imported Fertilizers
Straight Potassic	Straight Potassic	Straight Potassic
Muriate of potash	60 K2O	2049.24
Sulphate of potash	50 K2O	17.50
Straight Phosphatic
Rock phosphate	12-18 P2O5	102.96

27 (5/8)

---

Summary Cheat Sheet

Key Recall Points

• FERTILIZERS - USE is exam-relevant for SSAC122 and objective questions in soil science.
• Use soil-test based interpretation with focus on pH, CEC, and nutrient availability.
• Apply the 4R principle: right source, right rate, right time, and right method.

Exam Traps

• Do not mix up soil fertility concepts with fertilizer quantity alone.
• Numerical and term-based questions often test definitions, units, and threshold values.
• In problem-solving, interpretation must follow soil reaction, crop stage, and management context.

References

3 sources • [1] [2] [3]

[1]

ICAR e-Course: Soil Chemistry, Soil Fertility and Nutrient Management

Official

[2]

Brady and Weil, The Nature and Properties of Soils

Book

[3]

Indian Council of Agricultural Research

Official