The Fertilizers focuses on natural or synthetic substances applied to soil or plant tissues to supply essential nutrients crucial for growth and agricultural productivity.
Assertion (A) : Chemical fertilizers are necessary for the phosphorus need of plants.
Reason (R) : One metric ton of organic manure can barely supply 2 or 3 kg of phosphorus.
(A) and (R) are true and (R) is the correct explanation of
(A).
Correct Answer:
(A) and (R) are true but (R) is not the correct explanation of
The fertilizer is a substance added to soil to improve plant growth and yield. Nitrogen, Phosphorus and Potassium (N,P,K) are necessary elements of plants. Only 1.5 to 3 kg of Phosphorus is obtained from 1 metric ton of an organic manure. Thus, chemical fertilizers are necessary for the phosphorus need of plants.
Ques: 2
For wheat cultivation which fertilizer is used?
Correct Answer:
(A) Nitrogen
Nitrogen is an essential element of plants. For wheat cultivation, the nitrogen fertilizer is most important for its growth and development. The deficiency of nitrogen is probably the most common nutritional problem affecting the plants.
Ques: 3
The element not provided by the fertilizers is –
Correct Answer:
(B) Hydrogen
The fertilizer is a chemical or natural substance added to the soil to increase its fertility. There are at least 16 elements essential for the growth of the plant. Carbon, Hydrogen and Oxygen are derived from carbon dioxide and water. Nitrogen, Phosphorous, Potassium, Calcium, Magnesium, Boron, Chlorine, Copper, Iron, Manganese, Molybdenum and Zinc are normally derived from the soil in the form of inorganic salts.
Ques: 4
Which one of the following fertilizers leaves maximum acidity in the soil ?
Correct Answer:
(B) Ammonium Sulphate
The soil acidic causes a reduction in the yields of acid- sensitive crops. The acidic soils are readily identified by a soil test showing a low pH value. The soil reaction is alkaline when the pH value is above 7, neutral at 7 and acidic below 7. The extensive use of ammonium sulphate is not recommended on acidic soils because of its greater acidifying properties compared to other nitrogen fertilizers.
Ques: 5
Urea is
Correct Answer:
(A) A nitrogen containing organic compound
Urea is an organic compound whose chemical formula is CO(NH2)2. Nearly 46.7% of nitrogen in the urea is present in the form of amide. In the field of organic chemicals it is also called carbamide.
Ques: 6
Catalytic converters are generally made from:
Correct Answer:
(C) Hydrogen
Transition metals are used directly as catalysts in the anti–pollution catalytic converters in car exhausts. For example, expensive transition metals such as Platinum and rhodium are used in the catalytic converters in car exhausts to reduce the emission of carbon monoxide and nitrogen monoxide, which are converted to the non–polluting gases nitrogen and carbon dioxide.
2NO (g) + 2CO(g) —> N2 (g) + 2CO2 (g)
Ques: 7
Which of the following chemical fertilizers is relatively more soluble in water at 20oC?
Correct Answer:
(B) Urea
Urea is an organic compound that is only stable in an acidic environment. It is named after the Greek word 'Oura' meaning urine. Urea is very easily soluble in water as compared to other fertilizers.
Ques: 8
With reference to chemical fertilizers in India, consider the following statements :
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?
Correct Answer:
(B) 2 and 3 only
Statement 1 is incorrect as urea is a main chemical fertilizer and MRP of urea is statutorily fixed by the Government. Government has implemented the Nutrient Based Subsidy (NBS) policy w.e.f. 1.4.2010 for Phosphatic and Potassic (P&K) fertilizers. Under the policy, MRP of P&K fertilizers has been left open and fertilizer manufacturers/marketers are allowed to fix the MRP at reasonable rates as per market dynamics, while the Government announces nutrient based subsidy for them. Ammonia is used to produce various nitrogenous fertilizers, including urea. For the industrial purposes, ammonia is manufactured by Haber's process, for which hydrogen is obtained from natural gas. Natural gas contains methane (CH4) which is used to produce hydrogen with thermal processes, such as steam-methane reformation and partial oxidation. Hence, statement 2 is correct. Statement 3 is also correct as in India the domestic production of elemental sulphur is limited to by - product recoveries from petroleum refineries which is a raw material for phosphoric acid fertilizers.
Ques: 9
What can be the impact of the excessive/ inappropriate use of nitrogenous fertilizers in agriculture?
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.
Correct Answer:
(C) 2 and 3 only
The excess use of nitrogenous fertilizers in agriculture can affect environment in various manners for example, increment of acidity in the soil, leaching of ground water, eutrophication etc.