Question

The soil formed by leaching and oxidation is___________.
a.Black soil
b.Laterite soil
c.Arid soil
d.Alluvial soil

Answer 1

Hint: Soil, the biologically robust, porous channel that has evolved in the uppermost layer of Earth’s crust.It is developed through weathering processes led by biological, climatic, geologic, and topographic effects.

Complete Step by Step Answer:
Laterite is both a soil and a rock type abundant in iron and aluminium. Nearly all laterites are of rusty-red coloration, due to high iron oxide content. The important characteristics of the lateritic soils are their unusual color, poor fertility, and high clay content and lower cation exchange ability.

Looking at the above options:

Option a: Black soil is formed by the weathering of igneous rocks and also by the solidification of lava from the volcano eruption. It is most abundantly found in Chhattisgarh, Madhya Pradesh, Maharashtra and in some southern parts of India, comprising the Godavari and near to the Krishna valleys. This option is incorrect.

Option b: The laterite soil is formed under high temperature and heavy rainfall with alternate wet and dry periods. This directs leaching of soil, removing only oxides of iron and aluminum causing oxidation. It lacks fertility due to a lower base-exchanging ability and a lower quantity of nitrogen, phosphorus, and potassium. This option is correct.

Option c: Arid soils are formed due to fragmentation of adjacent rocks and are mostly blown from the Indus valley area and coastal regions. These soils lack nitrogen and humus with normal phosphate and iron content. They are mineral rich soils but the primary limitation is the lack of water. This option is incorrect.

Option d: Alluvial soils form by flooding. This is because floods occasionally deposit new sediment at the surface, alluvial soils can have an unusual layered look. Dark and light colors interchange, along with assorted sizes of gravel particles. This unusual layering method is called stratification. This option is incorrect.

Option 'b' is correct.

Note: Soil plays a crucial role in the Earth’s ecosystem. Without soil human life would be very tough. Soil furnishes plants with food for their roots and holds the essential nutrients for plants to grow; filters the rainwater and administers the discharge of excess rainwater thus, preventing flooding. Soil advantages are general capacities of soils that are vital for many agricultural, environmental, nature protection, landscape architecture and urban applications.