Environmental Studies ยท 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

A balance fertilizer for plants is

  1. urea

  2. super phosphate of time

  3. ammonium sulphate

  4. compost
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Compost is considered a balanced fertilizer because it contains a mix of essential nutrients (nitrogen, phosphorus, potassium) and organic matter that improves soil structure. Urea, super phosphate, and ammonium sulfate are single-nutrient fertilizers, lacking the complete balance plants need.

Multiple choice

Which of the following statement is/are false? a. Dark coloured soils are rich in organic matter than the light coloured soils. b. The difference in soil colour does not depends on the geographical location of the soil. c. Microorganisms cause the decomposition of dead plants and animals and release the minerals back to the soil.

  1. Only a

  2. a and b

  3. Only b

  4. a and c

  5. Only c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The difference in soil colour does not depend on the geographical location of the soil, is a false statement. Hence, it is the correct option.

Multiple choice

Which one of the following stands for the symbol pH?

  1. Phosphorus and hydrogen content in soil

  2. Percentage of Hydrogen in soil

  3. Proportion of potash and hydrogen in soil

  4. Concentration of hydrogen ions in the soil
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The symbol pH stands for 'potential of Hydrogen'. It is a logarithmic scale used to specify the acidity or basicity of an aqueous solution, based on the concentration of hydrogen ions (H+).

Multiple choice

Cattle-bone powder is used as fertilizer as it is rich in

  1. sodium

  2. phosphorus

  3. nitrogen

  4. potassium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cattle-bone powder, often called bone meal, is a slow-release organic fertilizer. It is highly valued for its high phosphorus content, which is essential for root development and flowering in plants.

Multiple choice

Which of these is not a nutrient for plants?

  1. Water

  2. Mineral ions

  3. Carbon dioxide

  4. Nitrogen gas
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Although nitrogen is an essential nutrient, most plants cannot utilize nitrogen gas (N2) directly from the air. They must absorb nitrogen from the soil in the form of nitrates or ammonium ions.

Multiple choice

All of the following contributes to the availability of nitrogen compounds in the soil, except

  1. azotobacter

  2. thunders from clouds

  3. bacterial decay of animal refuse

  4. addition of lime
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Azotobacter fixes atmospheric nitrogen, lightning converts nitrogen into oxides, and bacterial decay releases nitrogen from organic matter. Lime (calcium carbonate) is used to neutralize soil acidity and does not provide nitrogen compounds.

Multiple choice

Most of the plants obtain nitrogen from the soil in the form of

  1. nitric acid

  2. nitrites

  3. nitrates

  4. free nitrogen gas
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

While plants can absorb nitrogen as ammonium, the most common and abundant form of nitrogen uptake from the soil is nitrate (NO3-). Nitrates are highly soluble and easily transported through the plant's xylem.

Multiple choice

Which of the following substances is obtained from soil by a plant?

  1. Nitrogen

  2. Oxygen

  3. Carbon dioxide

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Plants absorb nitrogen from the soil in the form of nitrates or nitrites through their roots. While oxygen and carbon dioxide are primarily obtained from the air through leaves during respiration and photosynthesis, nitrogen is a crucial mineral nutrient sourced from the ground. Other minerals like phosphorus and potassium are also obtained from the soil.

Multiple choice

A technique used for studying the effect of deficiency or toxicity of mineral nutrients on plant growth and metabolism is called ______.

  1. hydroculture

  2. hydroponics

  3. solution culture

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Solution culture is the standard technique for growing plants in a nutrient solution to study the effects of specific mineral deficiencies or toxicities. Hydroponics is a broader term for growing plants in water, but solution culture is the specific experimental method for nutrient studies.

Multiple choice

Which of the following options is a dangerous aspect of lichens?

  1. Lichens are used for dye preparation.

  2. Lichens are used as nitrogen fixers.

  3. Lichens are used as indicators of pollution.

  4. Lichens accumulate minerals and radioactive derivatives.

  5. Lichens are soil-forming organisms.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lichens accumulate harmless minerals as well as radioactive derivatives of strontium and cesium, which are retained in high concentration. These isotopes get ingested by the animals feeding on it. When these animals are eaten by humans, it may reach at a dangerous level.

Multiple choice

A complete fertiliser is the one that

  1. is commercially manufactured using chemicals

  2. contains all three critical minerals like potassium, phosphorus and nitrogen

  3. adds humus to the soil

  4. contains organic farm waste

  5. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct answer as complete fertiliser is the one that has these three vital elements in it.

Multiple choice

Green manure is formed by which of the following?

  1. Decomposing farm waste material in pits

  2. Green plants roots, leaves and stem

  3. Action of earthworm on organic waste

  4. Mulching and ploughing sun hemp into soil

  5. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct answer because green manure is prepared by mulching and ploughing some plants like sun hemp and guar into the soil. These green plants turn into green manure which helps in enriching soil.

Multiple choice

Find the incorrect statement(s) about fertilisers.

  1. Fertilisers are a commercially produced plant nutrients.

  2. Fertilisers help in destroying soil fertility, if used in excess amount.

  3. Fertilisers are a rich source of potassium, nitrogen and phosphorus.

  4. Fertilisers contain organic matters such as farm waste, cow dung and vegetable waste.

  5. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Fertilisers do not contain any kind of organic matter.