Soil Science - Study Mode

[#826] The smallest volume that can be called 'a soil' is
Correct Answer

(A) Pedon

Explanation

Solution: Pedon is the smallest unit or volume of soil that contains all the soil horizons of a particular soil type. Soils as unions of modules known as pedons. Soils are encountered on the landscape as groups of similar pedons, called polypedons, that contain sufficient area to qualify as a taxonomic unit.

[#827] The diagnostic surface horizons are called
Correct Answer

(C) Epipedons

Explanation

Solution: The diagnostic surface horizons are called Epipedons . A horizon that forms at or near the surface and in which most of the rock structure has been destroyed. Epipedons are characterized by their colour, texture, structure and content of organic matter and certain plant nutrients.

[#828] B-horizon of the soil is also known as
Correct Answer

(A) Illuviated soil

Explanation

Solution: A soil profile is a vertical section of soil, divided into several layers called horizons. The main horizons are A, B, C and D. B horizon is commonly referred to as “Subsoil”. The B-horizon can accumulate minerals and organic matter that are migrating downwards from the A and E horizons. Because of this, it is also known as the illuviated or illuvial horizon .

[#829] Podzolization is a process of accumulation in soil
Correct Answer

(A) Silica

Explanation

Solution: Podsolization is a complex soil formation process by which dissolved organic matter like silica and ions of iron and aluminium, released through weathering of various minerals, form organo-mineral complexes and are moved from the upper parts of the soil profile and deposit in the deeper parts of soil. The surface soils have relatively infertile and high in silica because of the process of podsolization.

[#830] The bulk density of clay soil is
Correct Answer

(C) 1.10 gm/cm 3

Explanation

Solution: Bulk density is defined as the dry weight of soil per unit volume of soil. Bulk density is dependent on soil organic matter, soil texture, the density of soil minerals (sand, silt and clay) and their packing arrangement.
The bulk density of the clay soil is 1.10 grams per cubic centimetre.