Soil Science MCQ Question and Answer | Agriculture MCQ Question

Answer: Option A

An amphibole is a group of inosilicate minerals, forming a prism or needle-like crystals, composed of double chain SiO₄ tetrahedra, linked at the vertices and generally containing ions of iron and magnesium in their structures.
Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right hence, it is referred to as a dark amphibole.

Answer: Option D

Silicate clay is the electro-microscopic clay mineral, which a diameter of fewer than 2 microns.
The sources of negative charges on silicate clays are due to exposed crystal edges, Isomorphus substitution and anion exchange.

Answer: Option B

Sulphur is the most important nutrient for oil seed production. It is necessary for the synthesis of proteins, oils and vitamins. Sulphur is involved in the formation of chlorophyll, glucosides and glucosinolates and the activation of enzymes and sulphydrl (-SH) linkages that are the source of pungency in oils.

Answer: Option A

Flooded soils are a condition in which an area of soil is oversaturated with water, often due to natural occurrence or with the intended purpose of agricultural reasons like the cultivation of rice.
The most conspicuous chemical change that takes place in the flooded soil is the reduction of iron (Fe).
Competition generally limits the use of weaker electron acceptors, iron reducers may exist in the soil but will be dominated by the presence of denitrifiers, who will grow faster with access to their stronger electron acceptor.

Answer: Option D

The mineral Olivine is a magnesium iron silicate with the chemical formula (Mg²⁺, Fe²⁺)₂SiO₄. It is the primary component of Earth’s upper mantle, it is a common mineral in Earth’s subsurface, but weathers quickly on the surface.
Olivine is rich in magnesium as per the chemical formula. Magnesium-rich olivine crystallizes from magma that is rich in magnesium and rich in silica.