The Fertilizers

Total Questions: 21

11. How much amount of urea will be required for supplying 1 kg of nitrogen? [U.P. B.E.O. (Pre) 2019]

(a) 2.0 kg
(b) 2.2 kg
(c) 2.5 kg
(d) 2.7 kg

Correct Answer: (b) 2.2 kg

Solution:The amount of nitrogen in urea is approximately 46%. To supply 46 g of nitrogen, 100 g of urea is required. Therefore, for supplying 1000 g (1 kg) of nitrogen:

Hence, approximately 2.2 kg of urea will be required to supply 1 kg of nitrogen

12. With reference to chemical fertilizers in India, consider the following statements: [I.A.S. (Pre) 2020]

At present, the retail price of chemical fertilizers is market-driven and not administered by the Government.
Ammonia, which is an input of urea, is produced from natural gas.
Sulphur, which is a raw material for phosphoric acid fertilizer, is a by-product of oil refineries.

Which of the statements given above is/are correct?

(a) 1 only
(b) 2 and 3 only
(c) 2 only
(d) 1, 2, and 3

Correct Answer: (b) 2 and 3 only

Solution:Statement 1 is incorrect as urea is a main chemical fertilizer, and the MRP of urea is statutorily fixed by the Government. The Government has implemented the Nutrient-Based Subsidy (NBS) policy from 1st April 2010 for phosphatic and potassic fertilizers.

13. What can be the impact of the excessive/inappropriate use of nitrogenous fertilizers in agriculture? [I.A.S. (Pre) 2015]

The proliferation of nitrogen-fixing microorganisms in soil can occur.
The increase in the acidity of soil can take place.
Leaching of nitrate to the groundwater can occur.

Select the correct answer using the code given below:

(a) 1 and 3 only
(b) 2 only
(c) 2 and 3 only
(d) 1, 2, and 3

Correct Answer: (c) 2 and 3 only

Solution:The excessive use of nitrogenous fertilizers in agriculture can negatively impact the environment in various ways, such as increasing soil acidity, leaching into groundwater, and causing eutrophication.

14. Which of the following is consumed in the manufacture of urea fertilizer? [Uttarakhand P.C.S. (Mains) 2006]

(a) Carbon dioxide
(b) Sulphur dioxide
(c) Chlorine
(d) Nitric acid

Correct Answer: (a) Carbon dioxide

Solution:Urea or carbamide [CO(NH₂)₂] is an organic compound. It is colorless, odorless, highly soluble in water, and practically non-toxic. In industry, urea is produced using synthetic ammonia and carbon dioxide.

15. Why does the Government of India promote the use of 'Neem-coated Urea' in agriculture? [I.A.S. (Pre) 2016]

(a) Release of Neem oil in the soil increases nitrogen fixation by the soil microorganisms.
(b) Neem coating slows down the rate of dissolution of urea in the soil.
(c) Nitrous oxide, which is a greenhouse gas, is not at all released into the atmosphere by crop fields.
(d) It is a combination of a weedicide and a fertilizer for particular crops.

Correct Answer: (b) Neem coating slows down the rate of dissolution of urea in the soil.

Solution:When urea is applied to soil, it is hydrolyzed to ammonium (NH₄⁺) and then converted to nitrate (NO₃⁻) through nitrification. If nitrification occurs too quickly, nitrogen escapes into the atmosphere, reducing efficiency. Neem-coated urea slows this process, releasing nitrogen gradually, allowing plants to absorb more nutrients and leading to higher yields.

16. What percentage of phosphorus (P₂O₅) and nitrogen (N) is present in DAP? [U.P.P.C.S. (Mains) 2008]

(a) 10% N and 20% P₂O₅
(b) 18% N and 46% P₂O₅
(c) 30% N and 60% P₂O₅
(d) 35% N and 70% P₂O₅

Correct Answer: (b) 18% N and 46% P₂O₅

Solution:Diammonium phosphate (DAP) is a commonly used fertilizer with the formula (NH₄)₂HPO₄. It contains 18% nitrogen (N) and 46% phosphorus pentoxide (P₂O₅).

17. Which one of the following is a mixed fertilizer? [I.A.S. (Pre) 1995]

(a) Urea
(b) CAM
(c) Ammonium Sulphate
(d) NPK

Correct Answer: (d) NPK

Solution:NPK is a mixed fertilizer, composed primarily of nitrogen (N), phosphorus (P), and potassium (K). It is used to meet the different nutritional needs of plants.

18. Which of the following is not a chemical fertilizer? [Uttarakhand P.C.S. (Pre) 2010]

(a) Urea
(b) Sodium Sulphate
(c) Super Phosphate
(d) Potassium Nitrate

Correct Answer: (b) Sodium Sulphate

Solution:Urea, super phosphate, and potassium nitrate are chemical fertilizers. Sodium sulphate (Na₂SO₄) is the sodium salt of sulphuric acid and is not used as a chemical fertilizer.

19. The most popular fertilizer for foliar application is: [U.P. Lower Sub. (Pre) 2015 U.P.P.C.S. (Mains) 2015]

(a) Sodium Nitrate
(b) Urea
(c) D.A.P.
(d) Potassium Chloride

Correct Answer: (b) Urea

Solution:

Foliar fertilization means applying nutrients to plant leaves or needles. Urea is commonly used for foliar fertilization due to its high solubility and its rapid and effective absorption by leaves.

20. 'Humus' is an example of: [U.P.R.O./A.R.O. (Pre) 2014]

(a) Soil Structure
(b) Crystalloids
(c) Organic colloids
(d) None of the above

Correct Answer: (c) Organic colloids

Solution:Humus refers to the natural decay of material, such as leaves, in the soil's top layer. It is a dark organic material that forms when plant and animal matter decays.

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