Tag: soil profile

Questions Related to soil profile

Humus is an example of

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Crystalloids

  2. Organic colloids

  3. Soil structure

  4. None of the above

Show answer
Correct Option: B
Explanation:

There are four major types of colloids present in soil :

1. Layer silicate clays 
2. Iron and aluminum oxide clays (sesquioxide clays) 
3. Allophane and associated amorphous clays 
4. Humus. 
Layer silicate clays, iron and aluminum oxide clays, allophane and associated amorphous clays are inorganic colloids while humus is an organic colloid.
Therefore, the correct answer is option B. 

Pure clay is not suitable for plant growth because

evs mud and stones soil - formation and profile soil-nature soil profile

  1. It is chemically inert

  2. It is chemically active

  3. It forms a solid non penetrable mass

  4. All of the above

Show answer
Correct Option: C
Explanation:

Clay soil is soil that contains a high percentage of clay particles. It is slow to drain water and quick to harden leading to water logging. It blocks root absorption, which prevents plants from getting nutrients required for survival. Hence it is not suitable for plant growth. Thus the correct answer is option C.

Good soil is

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Which allows the limited amount of water into it

  2. Which allows to percolate the water slowly from it

  3. Which allows to pass water very quickly from it

  4. Which holds whole of water into it

Show answer
Correct Option: B
Explanation:

A good soil needs to be deep, fine-textured, moist, free-draining, loamy, and have an organic-rich topsoil. These properties best enable plant roots to take up nutrients, water and oxygen, and get enough support for rapid growth. In clay soils with small pore spaces, water moves slowly and spreads outward from where it is applied due to capillary action. In sandy soil, irrigation water can penetrate to 72 inches below the surface within 24 hours of application. In soils with a heavy clay content, water only penetrates to roughly 36 inches in 24 hours.

Therefore, the correct answer is option B.

Why is organic matter (humus) an important part of soil?

evs mud and stones soil - formation and profile soil-nature soil profile

  1. It helps to improve water infiltration

  2. It can break down organic pollutants

  3. It converts nitrogen in the air into nitrates used by plants

  4. It is rich in nutrients, which is important for fertility

Show answer
Correct Option: D
Explanation:

Humus controls and regulates many soil functions, as well as plant growth. The better the humus count in the soil, the healthier and more productive soil will be. Regardless of the program one uses in farming operations, the higher the humus count, the better the crop is grown yield. Good humus count in the soil will hold soil moisture longer, thus less water is required for crop production. Also, good humus count reduces both water and wind erosion of soil.

The soil near the surface is usually darker than about one meter down, this is because the top soil


evs mud and stones soil - formation and profile soil-nature soil profile

  1. Is richer in Ca and Mg

  2. Contains more organic matter

  3. Is wetter than the sub soil

  4. Is drier than the sub soil

Show answer
Correct Option: B
Explanation:

(b) Top soil contains decomposed and amorphous organic matter composing of sand with humus.

Humus is defined as

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Physical texture of soil

  2. Chemical composition of soil

  3. Decomposed organic matter in soil

  4. None of the above

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Correct Option: C

Precious stones, such as gem stones, are products of

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Volcanic rocks

  2. Sedimentary rocks

  3. Metamorphic racks

  4. Igneous rocks

Show answer
Correct Option: D
Explanation:
  • A gemstone, also known as the precious stone, jewel, a gem is a piece of mineral crystal which is cut and polished and it is used to make jewellery or other accessories. Gemstones are formed from igneous rocks. Interlocking crystals grow within intrusive igneous rock and may form gemstones depending on elements present, cooling time and the environment.
  • Hence precious stones, such as gemstones, are products of igneous rocks.
  • So, the correct answer is 'Igneous rocks'.

Column I represent the size of the soil particles and Column II
represents type of solid components. Which of the following is
correct match for the Column I and Column II.

Column I Column II
A. 0.2 to 2.00mm (i) Slit
B. Less than 0.002 mm (ii) Clay
C. 0.02 to 0.2 mm (iii) Coarse and particle
D. 0.002 to 0.02 mm (iv) Fine sand particle



evs mud and stones soil - formation and profile soil-nature soil profile

  1. (A) - (ii), (B) - (iii), (C) - (iv), (D) - (i)

  2. (A) - (iv), (B) - (i), (C) - (iii) , (D) - (ii)

  3. (A) - (iii) , (B) - (ii) , (C)-(iv), (D) - (i)

  4. None of the above

Show answer
Correct Option: C
Explanation:

The texture of soil is determined by the proportions of particles of different sizes. Coarse sand particles are of 0.2 to 2.00 mm in size; 0.02 to 0.2 mm particles constitute fine sand; 0.002 to 0.02 particles represent silt and particles smaller than 0.002 mm are called clay.




Major constituent of soil is

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Organic matter

  2. Inorganic matter

  3. Soil air

  4. Soil water

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Correct Option: B

O-horizon is a

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Top soil

  2. Sub-soil

  3. Organic layer

  4. Solum

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Correct Option: C