Question 1

Question 1How are soils formed?

Accepted Answer

The soils are formed by disintegration and denudation of rocks under specific natural conditions. The natural forces responsible for soil formation are water, wind, vegetation, animals and temperature variations. These forces lead to weathering of the rocks and formation of soil. This process of formation of soil is called pedogenesis.

Question 2

Question 2Name the factors responsible for soil formation.

Accepted Answer

The factors responsible for soil formation are following:Parent rock materialReliefClimateVegetationAnimalsInsectsMan

Question 3

Question 3Name the main components of soil.

Accepted Answer

The soil is composed of inorganic and organic components.Inorganic components: Following are the inorganic components of soil:Silica — is present in the soil in the form of small crystalline grains, the main constituent of sand.Clay — is a mixture of silicates and many other minerals such as iron, calcium, sodium, potassium and aluminium.Chalk (Calcium Carbonate) — provides the most essential elements for plant growth which is calcium.Organic components: Organic matter is formed by the decomposition of plant remains, animal waste and dead animals. The ultimate form of organic matter is humus.

Question 4

Question 4Name the major soils of India.

Accepted Answer

The major soils of India are:Alluvial SoilsBlack SoilsRed SoilsLaterite and Lateritic Soils

Question 5

Question 5Why are alluvial soils very fertile?

Accepted Answer

Alluvial soils are very fertile because of following reasons:It is rich in minerals like iron, magnesia, alumina, potash and lime. It is also rich in organic matter and humus.It is loamy.It has sufficient depth.It is renewed annually / replenished by floods.It is transported soil which brings along lots of minerals, alluvium and silt.It is non-porous and water retentive if all the minerals are present.

Question 6

Question 6How are black soils formed?

Accepted Answer

Black soils are formed from solidification of basic lava spread over large areas of Deccan Plateau during volcanic activity. Therefore, they are essentially formed by weathering of Deccan Trap. Black soils are formed in situ i.e., formed where they are found.

Question 7

Question 7Does black soil undergo leaching?

Accepted Answer

No, black soil does not undergo leaching. Black soil retains moisture and becomes sticky when wet. Due to this property, black soil does not undergo leaching.

Question 8

Question 8Give the other names for black soil. Name two characteristic features of black soil.

Accepted Answer

The other names for black soil are Regur Soil and Black Cotton Soil.The two characteristic features of black soil are:The black soil retains moisture and becomes sticky when wet.It releases moisture during dry period.

Question 9

Question 9Why are red soils not suitable for agriculture?

Accepted Answer

Red soils are generally low in nutrients and have poor water-holding capacity. They lack lime, magnesia, phosphate, nitrogen and humus. This makes red soils unsuitable for agriculture.

Question 10

Question 10What is leaching? Give an example of a leached soil.

Accepted Answer

Leaching is defined as the loss of soluble nutrients or substances and colloids from the top layer of soil by percolation or runoff due to heavy rainfall.Laterite soils are leached soils.

Question 11

Question 11What type of soil is widely distributed over the Ganga Basin?

Accepted Answer

Alluvial soils are widely distributed over the Ganga Basin.

Question 12

Question 12Which is the most widely transported soil?

Accepted Answer

Alluvial soil is the most widely transported soil as they are carried by the rivers.

Question 13

Question 13Which soil is found suitable for growing coffee in India?

Accepted Answer

Laterite soil is found suitable for growing coffee in India.

Question 14

Question 14Name the soil found on the summits of Eastern Ghats.

Accepted Answer

Laterite soils are found on the summits of Eastern Ghats.

Question 15

Question 15Name one important characteristic of mountain soil.

Accepted Answer

The mountain soils are heterogeneous in nature, and their character changes with mountainous environment and altitude.

Question 16

Question 16What are the properties of desert soils?

Accepted Answer

The properties of desert soils are:Low organic matter — Desert soils tend to have a low concentration of organic matter, as the dry conditions make it difficult for decomposing organisms to thrive.Low nutrient levels — Desert soils are often low in nutrients, particularly nitrogen and phosphorus, due to the limited availability of organic matter and the high rates of evaporation that occur in these regions.High salt content — Desert soils may have a high concentration of salt due to the dry conditions, which can cause salt to accumulate in the soil.Poor water-holding capacity — Desert soils tend to be well-drained and have a low water-holding capacity due to the low levels of organic matter and the high evaporation rates in these regions.

Question 17

Question 17How are laterite soils formed?

Accepted Answer

Laterite soils are formed due to atmospheric weathering of rocks under conditions of high temperature and heavy rainfall with alternate wet and dry periods. They are formed strictly under monsoon conditions. They are the residual soils formed by leaching due to tropical rains.

Question 18

Question 18Why does laterite soil undergo leaching?

Accepted Answer

The laterite soils are formed in area of high temperature and heavy rainfall. High temperature and heavy rainfall leads to leaching of Laterite soils. In addition, laterite soil tends to be well-drained, which means it does not retain water well. As it does not become sticky and wet, this also leads to its leaching.

Question 19

Question 19What is soil erosion? Name the different types of soil erosion.

Accepted Answer

The removal of topsoil by different agents of weathering like wind, running water, human activities, plants and animals is known as soil erosion.The different types of soil erosion are:Splash erosionSheet erosionGully erosion/ Rill erosion

Question 20

Question 20What is soil conservation? State two ways in which one can reduce soil erosion.

Accepted Answer

Soil conservation means the efforts made to prevent or reduce the loss of soil due to soil erosion and prevention of reduced fertility of soil caused by over-use, acidification, salinisation or other types of soil contamination.Two ways in which one can reduce soil erosion are:Through afforestation by increasing area under forests and stopping indiscriminate felling of trees.By checking overgrazing in grasslands

Soil Resources in India