Page 88 - Science Class 07

saline layer forms a hard crust. These soils are Importance of Soil
generally sandy and deficient in organic ma er. Soil is one of the most important natural
This soil has a very poor water retena on resources which support plant growth and
capacity. However, it contains good amount of ul mately help in produc on of food for all
soluble salt. So, it can be made fer le by adding living beings.

adequate amount of water to it. Let’s study importance of soil:
Mountain Soil v All kinds of vegeta on depend on soil for
Mountain soil is found in the Himalayan region. minerals, water, humus and physical

Heavy rainfall and abundant amount of humus support. However, different types of soil
present in the soil makes it very fer le. support different types of plant growth.
However, the composi on of mountain soil v Desert soil has very low water reten on
varies from place to place. But, due to capacity, besides, low rainfall also makes it
deforesta on this soil is losing its fer lity. dry. Therefore, the plants found in deserts
MOISTURE IN SOIL have deep roots that go deep in search of
Soil moisture is the water stored in the soil and water. Their leaves are modified into spines

is affected by precipita on, temperature, soil to prevent water loss. Their stems are
characteris cs and more. These some factors succulent to store water. The green stems
help determine the type of biome present, and of these plants also carry on photosyn-
the suitability of land for growing crops. The thesis. Cactus, bushes (Shrubs) are found in
health of our crops relies upon an adequate desert soil.
supply of moisture and soil nutrients, among v Clayey soil behaves like a hard mass. But
other things. As moisture availability declines, the plants that grow in clayey soil have
the normal func on and growth of plants are strong roots which loosen the soil and
disrupted, and crop yields are reduced. And, as prenetrate deep into the soil.
our climate changes, moisture availability is

becoming more variable.

Aim : To show that soil contains moisture.
Method : Take a small quan ty of soil from the garden and put it into
a boiling tube. Adjust the apparatus as shown below. Heat the tube.

On hea ng, your will observe water vapour condensing on the inner
sides of the tube. This water vapour comes from the soil. This
experiment proves that soil contains moisture.
In this way, these roots do not let the soil to form clump and keep
the soil aerated. This soil is good for growing rice, wheat, etc.

Loamy soil supports all types of plant growth because it is a good
mixture of sand, clay and humus. Besides it is rich in mineral
contents.

88 Science-7