Tag: soil profile

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Questions Related to soil profile

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

The Precambrian red rock indicates the ________________.

  1. Presence of the free oxygen

  2. Absence of free oxygen

  3. Presence of hydrogen

  4. Presence of water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The presence of red rocks (often banded iron formations) from the Precambrian era indicates oxidation of iron, which required the presence of free oxygen in the atmosphere.

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

The geological age of a rock is determined by.

  1. The fossil flora and fauna

  2. Chemical composition of the rocks

  3. Radiometric dating

  4. Spectroscopic data
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fossil flora and fauna are used in biostratigraphy to determine the relative geological age of sedimentary rock layers, as specific species existed only during certain time periods.

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

Humification results in the formation of ............. substance.

  1. Colloidal and Basic

  2. Acidic and Dark colored

  3. Amorphous and Light colored

  4. Light coloured colloidal
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Humification is a process in which organic material decomposes and breaks down. It results in the formation of humus. Humus is a dark-coloured, amorphous and acidic substance. 
  • It occurs in soils and peats. It improves the quality of soil by providing nutrient substances like nitrogen.

Thus, the correct answer is 'Acidic, Dark coloured.'

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

'X' is an organic substance obtained from the decomposition of plant or animals wastes which provides lots of humus to the soil. Identify the incorrect statements regarding decomposition.

  1. It makes the soil porous

  2. It reduces the water holding capacity of the soil

  3. it increase the number of friendly microbes

  4. It improves the texture of the soil
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Humus is the dark, organic material formed in the soil when plant and animal matter decays.
It is important as it retains-
1)  Moisture content in the soil.

2) Loosens the soil which allows better aeration and drainage.
3) It encourages the increase of soil organisms which help make nutrients available to plants. 
4) It makes the soil more porous.
5) High humus content increases water holding capacity of the soil.
So, the correct answer is 'It improves the texture of the soil'.

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

When a small amount of garden soil is put into a glass jar containing water, stirred and allowed to stand for two hours, the layers from top to bottom would be

  1. Debris, water, sand and clay

  2. Humus, water, clay and sand

  3. Debris, clay, gravel and sand

  4. Humus, clay, gravel and sand
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Soil is comprised of air spaces and organic matter, but mostly mineral particles. There are three kinds of soil minerals, sand, silt and clay. The relative percentage of each of these particles in the soil determines its texture. Sand has the largest soil particles (0.4- to 0.01-inch diameter) and the largest pores between particles. Silt soil particle size is between clay and sand (0.01- to 0.0001-inch diameter). The characteristics of silty soil are similar to those of clay, but are moderated by its larger particle size. Clay soil has the smallest soil particles (less than 0.0001-inch diameter) and the least amount of water and air spaces between particles. Humus is dark, organic material that forms in soil when plant and animal matter decays. The thick brown or black substance that remains after most of the organic litter has decomposed is called as humus. Hence, humus settles at the topmost and sand the lowermost since, its size is maximum.

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

Match the following.

Column I Column II
I. Sandy soil A. 85% sand + 15% clay or silt
II. Loam soil B. 70% sand + 30% clay or silt
III. Silt C. 50% sand + 50% clay or silt or both
  D. 90% silt + 10% sand

  1. I-A, II-D, lll-C

  2. I- A, II- B, lll- D

  3. I- A, II- D, lll- B

  4. I- A, II- B, lll- C

  5. I- A, II- C, lll- D
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Sand can refer to a textural class of soil or soil type; i.e., a soil containing more than 85% sand-sized particles (by mass) and 15% clay.

A loamy soil is one that combines sand and clay particles in relatively equal amounts. Loamy soil is ideal for most garden plants because it holds plenty of moisture but also drains well so that sufficient air can reach the roots. Loam is soil composed mostly of sand and silt, and a smaller amount of clay (about 70%-30% concentration, respectively). The soil can be called as silt if its silt content is greater than 90 percent.

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

Which of the following characteristics is not a function of humus in soil?

  1. Provides nutrients

  2. Raises pH

  3. Retains moisture

  4. Humus does all of the above in soil
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Explanation: Humus is the end product of broken down (decayed) organic matter. Humus is an essential component of healthy soils that has many great benefits.

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

Mineral nodules present in ocean which can meet shortage of important soil nutrient are

  1. Manganese nodules

  2. Phosphorite nodules

  3. Magnesium nodules

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Phosphorite rocks are spherical concentrations that are randomly distributed along the floor of continental shelves. It contains high amounts of phosphate minerals. 
  • The size of Phosphorite nodules can range up to several tens of centimetres.
  • Hence Mineral nodules present in the ocean which can meet the shortage of important soil nutrient are Phosphorite nodules.
  • So, the correct answer is 'Phosphorite nodules'.