Environmental Studies · Biology

Soil Science and Fertilizers

1,537 Questions

Soil science focuses on soil formation, classification, and fertility management using fertilizers and organic amendments. Agricultural and environmental science exams heavily feature questions on biofertilizers, mycorrhiza, and phytoremediation. Practice these questions to build a strong understanding of soil nutrient cycles.

Phytoremediation techniquesOrganic soil amendmentsBiofertilizers and mycorrhizaNitrous oxide emissionsIn-situ soil remediationGreen manuring effects

Soil Science and Fertilizers Questions

Multiple choice
  1. Sulphur

  2. Gypsum

  3. Lime

  4. Calcium Chloride

  5. Ferrous Sulphate

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Lime (calcium carbonate or calcium oxide) is used to reclaim acidic soils because it neutralizes soil acidity by raising the pH level. The calcium in lime replaces hydrogen and aluminum ions, making nutrients more available to plants. Sulphur would make soil more acidic, while Gypsum is used for sodic/alkaline soils, not acidic ones.

Multiple choice
  1. fertility rate

  2. iron and lime content

  3. water retention

  4. acid content

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Soil pH measures the acidity or alkalinity of soil on a scale of 0-14, with 7 being neutral. It indicates the concentration of hydrogen ions in the soil solution, which determines acid content. pH affects nutrient availability and microbial activity. Fertility, iron-lime content, and water retention are important soil properties but are not measured by pH.

Multiple choice
  1. mineral salts absorbed by the plant

  2. organic matter of the plant

  3. mineral salts and organic matter

  4. None of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Plant ash is an indication of mineral salts absorbed by the plant.

Multiple choice
  1. A bio-fertilizer can symbiotically associate with plant roots.

  2. It maintains the natural habitat of the soil.

  3. Bio-fertilizers are cost-effective.

  4. Azolla is an alternative phosphorus source.

  5. Rhizobium inoculation is a well-known agronomic practice to ensure adequate nitrogen.

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Azolla is a small, eukaryotic, aquatic fern having global distribution. Prokaryotic blue green algae Anabena azolla resides in its leaves as a symbiont. Azolla is an alternative nitrogen source. This association has gained wide interest because of its potential use as an alternative to chemical fertilizers.

Multiple choice
  1. Compost

  2. Humus

  3. Urea

  4. None of these

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Urea (NH2)2CO is a synthetic nitrogen fertilizer produced industrially through the Haber-Bosch process combining atmospheric nitrogen with hydrogen. Compost and humus are organic natural fertilizers, while urea is manufactured synthetically in chemical plants.

Multiple choice
  1. humus

  2. pests

  3. fertilizer

  4. rubble

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Humus is the dark, organic matter formed from the decomposition of plant and animal matter in soil. It is rich in nutrients and essential for soil fertility. Pests are harmful organisms, fertilizers are added to enhance soil, and rubble refers to broken stones or debris.

Multiple choice

As per the passage, which of the following items of expenditure involved in fertilizer pricing is not mentioned in the list of those which can be reduced?

Directions: Read the passage below and answer the question that follows:

Natural gas is the most efficient feedstock for production of urea. Energy consumption as well as the total cost of production of fertilizers is the least in gas–based plants as compared to the plants of comparable vintage based on naphtha, fuel oil and coal. At present, only 43.4 per cent of the capacity for producing nitrogen is based on natural gas.
It is, therefore, imperative that sufficient allocation of natural gas should be ensured for production of nitrogenous fertilizers. It has been reported that a lot of difficulties are being experienced by the fertilizer industry in getting allocation of gas for new projects which are about ten in number and even for expansion of existing projects.

The committee notes that the demand for gas by sectors other than fertilizer is mainly for energy, whereas fertilizer uses gas for both chemical and energy. In order to produce fertilizer at the least cost and to make the most productive use of gas, the Committee recommends that timely and sufficient allocation of gas on top priority basis be made to fertilizer projects.

One item of expenditure which can be considerably reduced by fertilizer units is advertisement through various media. Expenditure incurred by 22 units on advertisements amounted to as much as Rs. 2731 crores in 1988–89 and Rs. 2251 crores in 1989–90. As against this the expenditure incurred by those units for encouraging farmers to use fertilizers by distributing free samples, carrying out soil testing, etc. was a meagre amount of Rs. 298 crores and Rs. 417 crores in 1988–89 and 1989–90, respectively.

In the committee's view, the huge expenditure on advertisements through TV, etc., for promoting an individual company's products is largely avoidable as that amount correspondingly adds to fertilizer subsidy. The committee would recommend that fertilizer units should instead spend more on 'demonstration and sample' which is an effective and productive way of promoting fertilizer consumption.

Natural gas is the main feedstock for fertilizer industry, the price of natural gas supplied to fertilizer industry does not seem to reflect its true cost. The committee notes that about 22 percent of the total gas produced is flared by ONGC for want of facilities and the cost of gas so flared during the two years 1989–90 and 1990–91 alone amounted to as much as nearly Rs. 1800 crores. The committee notes that for determining the consumer prices of natural gas the cost of imported furnace oil is taken as the basis which has no relation to the actual cost of production. Similarly the producer price of gas is reportedly based on the cost of production of gas from South Bassein field. This does not take into account the weighted average of the cost of gas from other sources including the cost of gas flared. In view of these facts, the committee recommends that the price should be fixed on a rational calculation of production cost based on total production.

The royalty paid by fertilizer industry on natural gas during 1990–91 amounted to nearly Rs. 100 crores out of which the share of the Central government was about Rs. 89 crore. The committee desires that with a view to bringing down the subsidy burden on nitrogenous fertilizer the Central royalty on natural gas may be done away with. The transportation charges for gas sold along the HBJ pipeline appears to be on the higher side. As per the information furnished by the ministry of petroleum and natural gas, the cost of transportation of 1000 cu. mt gas for 1000 kms works out to Rs. 440. Against this, the rate charged is Rs. 875 per 1000 cu. mt, irrespective of distance.

The committee desires the government to examine this aspect and the transportation charges for gas sold to fertilizer units along the HBJ pipeline should be reviewed and re-fixed on reasonable and realistic bases. The committee also desires that in order to bring down the cost of transportation of gas along the HBJ pipelines, depreciation for HBJ pipelines may be raised to 25 years instead of ten years.

  1. Processing

  2. Advertising

  3. Transportation

  4. Cost of raw material

  5. None of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The author has described advertisement, transportation and cost of raw materials as factors of expenditure involved in pricing of fertilizers, which according to the committee’s recommendation can be reduced. Processing does not figure in the passage.

Multiple choice

Compared to 1988–89, advertising costs for fertilizers in 1989–90 have

Directions: Read the passage below and answer the question that follows:

Natural gas is the most efficient feedstock for production of urea. Energy consumption as well as the total cost of production of fertilizers is the least in gas–based plants as compared to the plants of comparable vintage based on naphtha, fuel oil and coal. At present, only 43.4 per cent of the capacity for producing nitrogen is based on natural gas.
It is, therefore, imperative that sufficient allocation of natural gas should be ensured for production of nitrogenous fertilizers. It has been reported that a lot of difficulties are being experienced by the fertilizer industry in getting allocation of gas for new projects which are about ten in number and even for expansion of existing projects.

The committee notes that the demand for gas by sectors other than fertilizer is mainly for energy, whereas fertilizer uses gas for both chemical and energy. In order to produce fertilizer at the least cost and to make the most productive use of gas, the Committee recommends that timely and sufficient allocation of gas on top priority basis be made to fertilizer projects.

One item of expenditure which can be considerably reduced by fertilizer units is advertisement through various media. Expenditure incurred by 22 units on advertisements amounted to as much as Rs. 2731 crores in 1988–89 and Rs. 2251 crores in 1989–90. As against this the expenditure incurred by those units for encouraging farmers to use fertilizers by distributing free samples, carrying out soil testing, etc. was a meagre amount of Rs. 298 crores and Rs. 417 crores in 1988–89 and 1989–90, respectively.

In the committee's view, the huge expenditure on advertisements through TV, etc., for promoting an individual company's products is largely avoidable as that amount correspondingly adds to fertilizer subsidy. The committee would recommend that fertilizer units should instead spend more on 'demonstration and sample' which is an effective and productive way of promoting fertilizer consumption.

Natural gas is the main feedstock for fertilizer industry, the price of natural gas supplied to fertilizer industry does not seem to reflect its true cost. The committee notes that about 22 percent of the total gas produced is flared by ONGC for want of facilities and the cost of gas so flared during the two years 1989–90 and 1990–91 alone amounted to as much as nearly Rs. 1800 crores. The committee notes that for determining the consumer prices of natural gas the cost of imported furnace oil is taken as the basis which has no relation to the actual cost of production. Similarly the producer price of gas is reportedly based on the cost of production of gas from South Bassein field. This does not take into account the weighted average of the cost of gas from other sources including the cost of gas flared. In view of these facts, the committee recommends that the price should be fixed on a rational calculation of production cost based on total production.

The royalty paid by fertilizer industry on natural gas during 1990–91 amounted to nearly Rs. 100 crores out of which the share of the Central government was about Rs. 89 crore. The committee desires that with a view to bringing down the subsidy burden on nitrogenous fertilizer the Central royalty on natural gas may be done away with. The transportation charges for gas sold along the HBJ pipeline appears to be on the higher side. As per the information furnished by the ministry of petroleum and natural gas, the cost of transportation of 1000 cu. mt gas for 1000 kms works out to Rs. 440. Against this, the rate charged is Rs. 875 per 1000 cu. mt, irrespective of distance.

The committee desires the government to examine this aspect and the transportation charges for gas sold to fertilizer units along the HBJ pipeline should be reviewed and re-fixed on reasonable and realistic bases. The committee also desires that in order to bring down the cost of transportation of gas along the HBJ pipelines, depreciation for HBJ pipelines may be raised to 25 years instead of ten years.

  1. decreased by 21%

  2. increased by 17%

  3. decreased by 18%

  4. decreased by 7%

  5. None of these

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Advertisement cost in 1988-89 = Rs. 2731 crore

Advertisement cost in 1989-90 = Rs. 2251 crore

Decrease                        = Rs. 480 crore
Decrease in percentage   = 480 x 100/2731                                        = 18% (approx.)