Soil Science

The crops are specific for the occurrence of symptoms of a particular deficient nutrient element exhibiting characteristic symptoms. Such crops are called Indicator crops for deficiency of that particular element.
Citrus fruits and cereals like wheat is the indicator of the copper element. A general wilting of the whole plant occurs at early tillering.

Soil physics is the study of soil’s physical properties and processes. It is applied to the management and protection of natural and managed ecosystems. Soil physics deals with the dynamics of physical soil components and their phases as solids, liquids and gases.
Daniel Hillel is the father of soil physics.

In agricultural soils, 10% of the total nitrogen is found as fixed ammonium ions. Ammonium and nitrate ions are the predominant inorganic forms of nitrogen in soils. Ammonium is available in the soil atmosphere in both exchangeable as well as non-exchangeable forms.
Nitrogen is a widely available element in our environment, it is available in different forms like ammonium ions, nitrate ions, nitrite ions or elemental forms.

Out of the given options, calcium is the immobile element. Immobile elements are such elements that cannot be moved by plants along with the nutrients within themselves from older tissues to newer tissues.

The solum (plural sola) in soil science consists of surface and subsoil layers that have undergone the same soil forming conditions.
The base of the solum is un-weathered parent material and it is the upper surface can also be called as ‘floor’.

Grasslands are areas where the vegetation is dominated by grasses.
The spheroidal structure is dominant in grasslands, these have granular soil structure. The aggregates are 1 – 10 mm in diameter with rounded corners. This structure is usually seen in the A horizon or the layer of fine or medium-textured soils.

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.

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.

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.

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.