Chapter 6
Soil
1. 1. Find the correct answer from the following answers.
(i) Which of the following types of soil is widely available and more productive?
(a) Alluvial soils
(b) Laterite soils
(c) Black soil
(d) Forest land
Answer: (a) Loam soil.
(ii) Which is also known as regur soil
(a) Saline soils
(b) Dry soil
(c) Black soil
(d) Laterite soils
Answer: (c) Black soil.
(iii) Which of the following causes the topsoil of India to disappear?
(a) Wind mining
(b) Water excavation
(c) excessive leaching
(d) None of the above
Answer: (a) Wind mining.
(iv) Which of the following irrigation increases the salinity of the cultivated soil?
(a) Gypsum addition
(b) Eating too much grass
(c) Excessive water supply
(d) Application of fertilizers
Answer: (c) Excessive water supply.
2. 2. Answer within 30 words.
(i) What is soil?
Answer: A substance formed by the combination of rock formations and organic matter on the surface of the Earth. It is called the soil. This is the substance in which plants grow.
(ii) What are the main factors responsible for soil formation?
Answer: The main factors responsible for soil formation are relief, nutrients, climate, plant life and time. In addition to these, human activities have a significant impact.
(iii) Mention the three horizons or zones of the soil profile
Answer: The three horizons or zones of the soil profile are:
(a) Horizon 'A'
(b) Horizon 'B'
(c) Horizon 'C'
Horizon 'A' is the level at the very top of the ground. Here organic matter is attached to metallic matter as well as nutrients and water which facilitate plant growth. Horizon 'B' is an intermediate zone A' and 'Zone C'. The materials of this horizon or zone come from Zone A and Zone C. This horizon or zone contains some organic matter but mostly inorganic matter that is subject to degradation. Horizon C consists of completely missing bedrock.
(iv) What is meant by soil degradation?
Answer: Years of soil use reduce the fertility of the soil. This destroys the natural properties of the soil. This soil degradation is called soil degradation.
(v) What is the difference between khadar and bhangar?
Answer: The difference between shaft and cannabis is-
(a) Ditch type is new silty soil and it is deposited annually by floods on the banks of rivers. Cannabis, on the other hand, is old alluvial soil, found far from floodplains.
(b) Trench soils are more fertile. Cannabis soils, on the other hand, are less fertile.
3. 3. Answer in 125 words.
(i) What is black soil? How is it formed and what are its characteristics?
Answer: Soils that are usually deep and impermeable and swell and become sticky when water falls and shrink in dry weather. Soil with such properties is called black soil. This soil is also called 'rest soil' or 'black cotton soil' This soil is derived from basaltic rock. Due to its low water absorption and quick release, black soils retain water vapor for a long time which helps rain dependent crops to survive even in drought. It is found mainly in Maharashtra, Madhya Pradesh, Gujarat, Andhra Pradesh and Tamil Nadu.
The main characteristics of black soil are:
(a) Black soils are high in lime, iron, magnesia, alumina etc.
(b) Sufficiently fertile and suitable for crop production.
(c) This soil is low in phosphorus, nitrogen and organic matter.
(d) This soil is very suitable for cotton cultivation. Therefore, this soil is also called black cotton soil.
(e) This soil can retain water vapor for a long time.
(f) The color of this soil is usually deep black to gray.
(ii) What is soil conservation? Write about some ways to conserve soil.
Answer: Soil conservation is a method by which soil fertility can be maintained, soil erosion can be prevented and soil degradation can be improved.
Currently, various methods are used to conserve soil. Some of the ways of soil conservation are convex dams, convex altars, regularization of forests, control of cattle grazing, cultivation of cover crops, mixed farming, crop rotation etc.
Convex dams to prevent soil excavation on sloping soils will conserve soil in hilly areas.
The soil becomes loose as grazing animals eat grass and trees. As a result, the soil is not preserved. Controlling cattle grazing will prevent soil loosening and preserve the soil.
In the absence of forests, soil is excavated very quickly. It is very important that we plant trees to prevent this mining.
(iii) How do you know if a type of soil is fertile? Write down the differences between naturally fertilized soil and artificially fertilized soil.
Answer: The differences between naturally fertilized soil and artificially fertilized soil are:
The fertility of naturally fertile soils increases naturally. Therefore, these soils are called natural fertile soils. This soil is very suitable for cultivation. Natural fertile soils have different composition, color and soil properties. This humus is also found.
To increase the fertility of artificially fertilized soils, certain amounts of chemical fertilizers should be applied to the soil. This means that the fertility of the soil is increased only by the application of chemical fertilizers. Therefore, this soil is called artificially fertilized soil. Chemical fertilizers are applied every year to cultivate this soil. Otherwise, this fertility will be lost if fertilizer is not applied. This causes deterioration of soil properties. etc.
