QUESTION – 2
The upper layer of the earth which is composed of different thin rock particles is helpful in the growth of vegetation and plants that is called soil.
Basic Components of Soil
Soil has three basic components.
1. Solid particles like salt, mineral and organic matter.
Importance of Soil
The kind of soil totally depends upon climate, location, vegetation and rock material. The agriculture of a country depends upon her soil’s structure and kinds. Soil is a gift of nature.
Those materials which are transported from one place to another by rivers and deposited at other places are called alluvium.
Similarly wind also transports the material from one place to another which is deposited over the surface that is called Aeolian Soil.
Classification of Soils
The soil of Pakistan may be classified according to the regional basis.
Indus basin Soils
The indus plain is made with the deposition of alluvium by the indus river its tributaries. For the last thousands of years rivers have been depositing the soil in the form of layers. These soils have more calcium carbonate and less organic matter. These soils are divided into three main categories.
Bongar soils cover a vast area of indus plain. The area includes most of the part of Punjab, Peshawar, Mardan, Bannu and Kachhi plain. A major part of the province of sindh is also comprised of these soils. Some of these soils are rich and irrigated give very good production. Usually these soils are far from the present rivers beds.
Khaddar soils are also formed along the rivers. So every year new layer of salt clay is deposited. These soils have low content of organic matter and salt.
Indus Delta Soils
These soils cover the river Indus Delta. They extent from Hyderabad to the south coastal area. Most of the soils is clay and developed under floodwater. Rice is cultivated in the major part of these soils.
These soils mostly cover the highlands of northern and western areas of Pakistan. The soils of northern mountainous areas have high content of organic matters because the climate is moist. Whereas the soils of western mountainous areas have high content of calcium carbonate and low content of organic matter because the climate of these areas is arid and semi-arid. The soils of Pothwar plateau have high lime content. They are productive when plenty of water is available.
Sandy Desert Soils
The soils cover the western areas of Balochistan, Cholistan and the desert of Thar in Pakistan. They are formed by layers of sand particles. They have moderate quantity of calcium carbonate. They are made of disposition of sandy soil layer by layer Arid and semi-arid type of climate effect these soils. So the economic activities are very low in deserts.