Environmental Studies · Biology

Soil Science and Fertilizers

1,509 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

From where do the plants get nitrogen?

  1. Soil

  2. Atmosphere

  3. Water

  4. Both (1) and (3)

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

Plants get nitrogen from the soil by the activity of bacteria present in their root nodules, which convert atmospheric nitrogen into usable form. 

Multiple choice

Which of the following options is not a function of bacteria?

  1. Breakdown of organic waste into harmless and usable substances

  2. Decomposition of non-biodegradable waste

  3. Increase in soil fertility

  4. Used in baking industry for preparation of breads, pasteries and cakes

  5. Preparation of medicine
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bacteria do not decompose non-biodegradable wastes.

Multiple choice

How plant waste is decomposed?

  1. By the action of enzymes present in the waste.

  2. Soil provides catalyst which helps in decomposition.

  3. By the action of microbes present in the soil.

  4. Nutrients and minerals present in the soil helps in decomposition.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Plant waste decomposition is carried out by soil microbes (bacteria, fungi, actinomycetes) that secrete enzymes breaking down cellulose, lignin, and other organic compounds into simpler substances for nutrient cycling.

Multiple choice

Consider the following facts:

  1. Nutrient cycle traces the movement of only organic matter in the living world.
  2. Detritus is the term used to describe non-living organic material.

Which of the above given facts is/are true?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A nutrient cycle (or ecological recycling) is the movement and exchange of organic and inorganic matter back into the production of living matter. The process is regulated by food web pathways that decompose matter into mineral nutrients. In biology, detritus is non-living particulate organic material (as opposed to dissolved organic material). It typically includes the bodies or fragments of dead organisms, as well as faecal material.

Multiple choice

Which of the following organisms do not decompose the organic matter in the soil?

  1. Fungi

  2. Plants

  3. Bacteria

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

Plants are producers, not decomposers. They do not break down organic matter; rather, they contribute organic matter to soil through leaf litter and root death. Fungi, bacteria, and earthworms are all decomposers that break down organic material, recycling nutrients back into the soil.

Multiple choice

Which of the following is a biotic component that affects the fertility of soil?

  1. pH

  2. Air content

  3. Fertilisers

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

Among the options, only plants (D) are biotic (living) components. pH and air content are abiotic factors, while fertilizers are human-added inputs. Plants affect soil fertility through organic matter addition, root exudates, and nutrient cycling - they are living components of the soil ecosystem.

Multiple choice

What should be added to soil, if it is alkaline in nature?

  1. Lime

  2. Calcium Carbonate

  3. Peat

  4. Water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Alkaline soil has high pH and needs acidification. Peat is acidic and organic, making it ideal for lowering soil pH. Lime (calcium oxide) and calcium carbonate would make soil more alkaline - they're used to treat acidic soil, not alkaline soil. Water is neutral and won't change pH.

Multiple choice

Vermicomposting is hastened by ________ .

  1. chemicals

  2. earthworms

  3. birds

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

Vermicomposting is the process of composting organic waste using earthworms, which accelerate decomposition by breaking down matter through their digestive system. Chemicals would be harmful, while birds and insects are not the primary agents in vermicomposting.

Multiple choice

Which of the following is composed of inorganic matter, which supplies nitrogen, phosphorus and potassium to the plants?

  1. Manure

  2. Pesticides

  3. Weedicides

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

Fertilizers are manufactured or mined substances containing inorganic compounds of nitrogen (N), phosphorus (P), and potassium (K) - the three primary macronutrients plants need in large quantities. Manure is organic matter from decomposed waste. Pesticides kill pests, and weedicides specifically target weeds. Fertilizers are distinct because they supply concentrated inorganic nutrients.