Geo Ch 1 Resources and development

 Ch 1 Resources and development

Dt:21/4/21

Classification of Soil:

Soil is categorized in many types on the basis of texture, colour, age, chemical properties, etc. India is a vast country which comprises of many types of land. Thus, many types of soils are found in different regions in India.

Alluvial Soil

Availability: Alluvial soil is found near the river or plains formed by rivers. Alluvial soil is considered relatively younger in age. In India, alluvial soil is found in the north eastern plain where Ganga, Yamuna, and Brahmaputra flow. Alluvial soil is deposited by river system. Entire northern plain is made of alluvial soil.

Alluvial soil is also found in eastern coastal plains near the Mahanadi, the Krishna, the Godavari and the Kaveri rivers.

Nature: Alluvial soil is very fertile, thus plains of Ganga, Brahmaputra, Yamuna, etc. are densely populated. Alluvial soil is the mixture of various proportions of silt, sand and clay. Alluvial soils differ in the size of their particles at the area of break of slope.

Apart from the size of particles of grains, soils are also classified on the basis of their age. The older alluvial soil is known as Bangar and new alluvial soil or Khadar. New alluvial soil has more concentration of coarse grains while Old alluvial soil has plenty of fine particles.

Alluvial soil is rich in potash, phosphoric acid and lime. Because of presence of these chemicals alluvial soil is good for the growth of sugarcane, paddy, wheat, maize, and pulses.

Black Soil

Availability: Because of black colour, this type of soil is called black soil. It is also known as Regur Soil. Black soil is found in the north west deccan plateau. It is found in the plateau of Maharashtra, Saurashtra, Malwa, Madhya Pradesh and Chattisgarh and extent along with the valley of Krishna and Godavari Rivers.

Nature: Black soil has high concentration of fine particles and thus can hold moisture for long time. It contains calcium, potassium, magnesium and lime. Black soil is suitable for the growth of cotton, but many other crop are grown in the area of black soil.

Red and Yellow Soil

The soil looks red due to presence of iron in crystalline or metamorphic rocks. When the soil look yellow when it occurs in dehydrated form. Red soil is present in the eastern and southern parts of the Deccan Plateau. Red soil is also found in Orissa, Chhattisgarh, on the southern part of the Gangetic plains and along the piedomont zone of the Western Ghats.

Laterite Soil

Laterite soil is formed in regions which get high rainfall with high temperature. This causes leaching of the soil and microorganisms are killed during the process. Due to this, laterite soil does not contain humus or contains very low amount of humus. This soil is mainly found in Kerala, Karnataka, Tamil Nadu, Madhya Pradesh and in hilly areas of Orissa and Assam. This soil can be made cultivable with heavy dose of manures.

Arid Soil

Arid soil is found in those areas which receive scanty rainfall. Due to high temperature, evaporation is faster in these regions. The soil has a high content of salt. Arid soil can be made cultivable with proper treatment. Arid soil is present in Rajasthan and Gujarat.

Forest Soil

The forest soil is found in hilly areas. The soil in upper parts is highly acidic because of denudation. The soil in the lower part is highly fertile.

Soil Erosion and Soil Conservation

Removal of top soil is called soil erosion. Intense farming, grazing, construction activities and other human activities; along with deforestation have led to soil erosion. Soil erosion; if not checked in time; can even lead to desertification.

Soil conservation is important to prevent soil erosion. Soil conservation can be done by many methods. Afforestation is the main method because trees hold the topsoil in place. Terrace farming and shelter belt planting also help in soil conservation.