Question

The soil that has very poor fertility status ____________.
A. Alluvial soils
B. Black cotton or regular soils
C. Laterite soils
D. Red soils

Answer 1

Hint: Soil is a layer of unconsolidated material at the surface of the earth, derived from organic matters and rocks through the disintegration and decay of rocks and organic matter. Nature takes thousands of years to build up soils.

Complete Answer: The productivity of soil depends upon its fertility. A number of physical properties such as texture, colour and arrangement of the particles of soil, the volume and form of its pores and its effective depth decide soil fertility. The flow and storage of water, the movement of air and the ability of the soil to supply nutrients to plants depend upon its physical properties.

Now let us examine the options:
Option A - Alluvial soils have come into existence due to the deposition of silt by rivers. This type of soil is rich in mineral contents, potash, phosphoric acid and lime. Rich in organic matter with a thickness exceeding 390 metres make it suitable for agricultural purposes.
Option B - Black soil came into existence by weathering of lava spread over large areas during the volcanic eruption. The soil is very fertile and manuring of the field is not required. Soil nutrients like calcium, carbonate, magnesium carbonate and iron contents are found in abundance. This soil is capable of maintaining moisture for long periods.
Option C - The soil which came into existence because of the leaching processes in the heavy rainfall areas of tropical India, is called Laterite Soil. It is less fertile and only grows grass in abundance. Option D - Red soils have come into existence by the weathering of igneous rocks of the old Gondwanaland. It contains higher contents of lime, potash and iron. These soils are full of pebbles and gravels. Hence, they are less fertile and are capable of growing millets only. Where they are fine-grained, they are more fertile.

The Laterite soil is less fertile as compared to the other soils. Thus, the correct answer is option (C).

Note: The soil with poor fertility status lacks moisture as the leaching process enables moisture to go down. It is devoid of soda and lime, phosphorus and nitrogen are found in insufficient amounts. Regions, where these types of soils are found, include Sahyadris, Chota Nagpur Plateau, parts of Orissa, Andhra Pradesh and Tamil Nadu.