Which one is the main source of minerals essential for man and other organisms?

Identify the function of soil.

Which of the following types of soil is transported by air?

The $O$ soil layer is rich in:

Select the correct statements regarding the role of soil:
$(I)$ Soil is a reservoir of essential elements.
$(II)$ Soil not only supplies minerals but also harbours nitrogen-fixing bacteria.
$(III)$ Soil acts as a matrix.
$(IV)$ Soil holds water and supplies air to the roots.

Give scientific reasons:
$(1)$ Hydroponic method is most suitable for plant culture.
$(2)$ Soil is known as reservoir of mineral elements.