Tag: soil properties

Questions Related to soil properties

Physical and chemical conditions of soil are studied under ..... factors.

  1. Biotic

  2. Climatic

  3. Edaphic

  4. Topographic


Correct Option: C
Explanation:

Edaphic factor is an abiotic factor relating to the physical or chemical composition of the soil found in a particular area. For example, very alkaline soil may be an edaphic factor limiting the variety of plants growing in a region.

An example of nitrogen fixing bacteria in the soil

  1. Rhizobium

  2. Nostoc

  3. Azotobacter

  4. Nitrobacter


Correct Option: C

Plants flourishing in acidic soils are

  1. Psammophytes

  2. Oxalophytes

  3. Sciophytes

  4. Heliophytes


Correct Option: B
Explanation:

Oxalophytes are the plants that grow in acidic soil that maintained at pH 5.5 as this enables the plant to absorb nutrients required for the growth.

Plants growing on sandy soils are known as psammophytes. 
Sciophytes are shade loving plants while heliophytes are sun loving plants. 
Thus, correct answer is option B. 

A good soil is that which 

  1. Holds whole of the water entering into it

  2. Allows limited amount of water into it

  3. Allows the water to percolate slowly into it

  4. Allows the water to pass very quickly from it


Correct Option: C
Explanation:

A good soil is that which allows the water to percolate slowly into groundwater. These soils can remove pollutants and they promote the growth of healthy vegetation, which in turn reduces soil erosion. 

Therefore, the correct answer is option C.

pH of a normal fertile soil is

  1. 4 - 5

  2. 6 - 7

  3. 7.2 - 9.0

  4. None of the above


Correct Option: B
Explanation:

Soil pH is in the range of 6 to 7 for most plants but some prefer acid or alkaline conditions. At this pH soil organic matter and structure is very good. A lot of micro-organisms, that support plant growth can live in the soil at this pH.

The soil near the surface is usually darker, than the soil about one meter down. This is because the topsoil is 

  1. Young and wet

  2. Richer in organic matter

  3. Richer in Ca and Mg

  4. Dry


Correct Option: B
Explanation:

Plants and animals aid in the development of a soil through the addition of organic matter. Fungi and bacteria decompose this organic matter into a semi-soluble chemical substance, known as humus. Larger soil organisms, like earthworms, beetles, and termites, vertically redistribute this humus within the mineral matter found beneath the surface of a soil. Humus is the biochemical substance, that makes the upper layers of the soil become dark. It is coloured as dark brown to black. 

Solubility and availability of plant nutrients are related to

  1. Soil pH

  2. Soil porosity

  3. Soil temperature

  4. Soil colour


Correct Option: A
Explanation:

Soil pH is important because it influences several soil factors affecting plant growth, such as :

(1) soil bacteria, 
(2) nutrient leaching, 
(3) nutrient availability, 
(4) toxic elements, and 
(5) soil structure. 
Bacterial activity that releases nitrogen from organic matter and certain fertilizers is particularly affected by soil pH, because bacteria operate best in the pH range of 5.5 to 7.0. Plant nutrients leach out of soils with a pH below 5.0 much more rapidly than from soils with values between 5.0 and 7.5. Plant nutrients are generally most available to plants in the pH range 5.5 to 6.5.

Which is best for plant growth?

  1. Loamy soil

  2. Silt

  3. Sandy soil

  4. Clay soil


Correct Option: A
Explanation:

Loam is considered ideal for gardening and agricultural uses, because it retains nutrients well and retains water, while still allowing excess water to drain away. 

Silt is granular material of a size between sand and clay, whose mineral origin is quartz and feldspar. 
Sandy soils are granular soils, that contain small rock and mineral particles. 
Clay is a fine-grained natural rock or soil material, that combines one or more clay minerals with traces of metal oxides and organic matter.

Soil hold water in it, it is called as 

  1. Soil water

  2. Ground water

  3. Soil moisture

  4. None of the above


Correct Option: C
Explanation:

Soil water is often referred to as soil moisture. Soil is the amount of water present in the interparticle spaces in the soil and is available to plants. When soil moisture gets depleted, enough water is not available for plants. So they have to apply more pressure in obtaining water from around the soil particles. 

So, option C "Soil Moisture" is the correct option.

A fertile soil is likely to have a pH value of

  1. 3-4

  2. 8-9

  3. 6-7

  4. 10-11


Correct Option: C
Explanation:

Soil pH is important because it influences several soil factors affecting plant growth, such as (1) soil bacteria, (2) nutrient leaching, (3) nutrient availability, (4) toxic elements and (5) soil structure. Bacterial activity that releases nitrogen from organic matter and certain fertilizers is particularly affected by soil pH, because bacteria operate best in the pH range of 5.5 to 7.0. Plant nutrients leach out of soils with a pH below 5.0 much more rapidly than from soils with values between 5.0 and 7.5. Plant nutrients are generally most available to plants in the pH range 5.5 to 6.5. For most plants, the optimum pH range is from 5.5 to 7.0.

Therefore, the correct answer is option D.