Soil Science MCQ Question and Answer | Agriculture MCQ Question

Tourlamine is the one mineral among the given options that is the main source of boron in soils.
Tourmaline is a crystalline silicate mineral group in which boron is compounded with elements such as aluminium, iron, magnesium, sodium, lithium or potassium.
It occurs as long, slender to thick prismatic and columnar crystals that are usually triangular in cross-section.

Azotobacter, Beijerinickia and Rhizobium all the given options are an example of Gum producing Bacteria.
The gums produced by bacteria are polysaccharides, high molecular weight polymers that are produced by the cell-wall anchored enzymes of microorganisms. The gums are composed of sugar residues linked by glycosidic linkages and may be linear or highly branched.

Bone meal is a mixture of finely and coarsely ground animal bones and slaughterhouse waste products. It is used as a dietary supplement to supply calcium and phosphorus to monogastric livestock in the form of hydroxyapatite.
It is slow release organic fertilizer, it supplies phosphorus, Calcium and a small amount to plants.
Bone meal contains 20% of P₂O₅.

Equivalent acidity is defined as the acidity developed by a fertilizer when applied to soils, measured in terms of calcium carbonate required for its neutralization.
It can be calculated as the calcium carbonate required to neutralize the acid residues caused by acidic fertilizers in the soil.
The equivalent acidity of anhydrous ammonia is 148. It is the highest among all the fertilizers.

Chernozems are humus-rich fertile black grassland soils used extensively for growing cereals or for raising livestock. It has a lighter lime-rich layer beneath, typically occurring in the temperate occurring in the temperate grasslands of Russian steppes. Thus it is mainly found in Russia.
Wheat, barley and maize are typically the principal crops grown, alongside other food crops and vegetables.

The mineral pyrite or iron pyrite also known as fool's gold, is an iron sulphide with the chemical formula FeS₂. Pyrite is the most abundant sulphide mineral.
Its metallic luster and pale brass hue give it a superficial resemblance to gold, thus also known as fool’s gold.
It is usually found associated with other sulphide or oxides in quartz veins, sedimentary rock and metamorphic rock, as well as in coal beds.

The Law of limiting factors is given by Blackman in 1905. He was a plant physiologist with his study on limiting factors on a plant's photosynthesis system.
As per the law, he stated that several factors regulate the biological process but the factors in different amounts affect the process on the whole.
Like in the case of the process of photosynthesis, the rate of the photosynthesis process is limited by the pace of the slowest factor.

The specific surface area of a soil sample is the total surface area contained in a unit mass of soil. Soils with high specific surface areas have high water-holding capacities, more adsorption of contaminants, and greater swell potentials.
The specific surface is calculated by the surface area of the solid particles divided by the mass of the solid particles.
The specific surface of a spherical soil particle having a 1.5 diameter is 4.

Cat clay or Acid Sulpahte soils found in Kerela is known as Kari soils and Pokkali soils. Acid sulphate soils are naturally occurring soils, sediments, or organic substrates that are formed under waterlogged conditions.
Kari soil of Kerala is the rice bowl of Kerala, is a problem soil affected by severe acidity and periodic saline water inundation with consequent accumulation of soluble salts which results in lower yield.
Pokkali soil is formed from river alluvium and Sulphur rich marine sediments and is potential acid sulphate.