Soil Resources

Question 1

What is soil?

Answer 1

Soil is the layer of loose mixture of small rock particles and rotting organic matter that make up much of the world’s land surface.

Question 2

What is the importance of soil?

Answer 2

1. It provides a medium for plant growth
2. It supports life
3. Useful for groundwater storage

Question 3

Why is humus important in soil?

Answer 3

It is made up of organic matter and determines the fertility of soil.
It helps it hold more moisture
It restores plant nutrients
it removes excessive alkaline soil or acids
Helps in the formation of the crumb structure and allows more aeriation

Question 4

Advantages and disadvantages of different textures of soil.

Answer 4

Sandy soil:
Water and air can easily permeate through the soil, aerating plant roots but the soil dries up easily.

Clayey soil:
Can hold moisture which is released to plants during dry seasons. When it is wet, it is hard to plough

Loamy soil:
Good for farming and gardening

Question 5

What is soil fertility?

Answer 5

THe power of soil to support vegetation

Question 6

Characteristics of fertile soil.

Answer 6

Adequate depth - space for roots to grow completely and provides proper aeration
Adequate nutrients - for proper plant growth
High moisture levels - Helps with uptake of dissolved nutrients

Question 7

How is alluvial soil formed?

Answer 7

Formed by alluvial deposits on river banks and streams. The material is brought from deposition of erosional products and laid down by various rivers. It is ex situ soil.

Question 8

Characteristics of alluvial soil.

Answer 8

1. Sandy and course in upper layer, clayey and fine is lower layer
2. Fertile - rich in minerals like lime, potash, potassium.
3. Deficient in nitrogen & humus except in the Ganga deltaic region which is rich in humus
4. More alkaline in drier areas

growing rice and jute

Question 9

What is Bhangar soil? What are its features?

Answer 9

Old alluvium soil found in higher regions of rivers
1. clayey, non-porous
2. coarser texture - presence of kankar (lime nodules)
3. less fertile - not replenished by floods every year

Question 10

Where are the different types of alluvial soil found?

Answer 10

Inland - Indus, Ganga, Brahmaputra - Punjab and Sindh to Bangladesh and Assam. Incl. Haryana, Punjab, Bihar, UP, WB, Assam

Deltaic - ganga, Mahanadi, Kaveri, Krishna, Godavari, Brahmaputra

Coastal - Coastal strips of peninsular India

Question 11

Why is Black soil also called Volcanic soil?

Answer 11

Called volcanic, lava, residual, regur or black cotton soil as it is formed from weathering of laval rocks (basalt)