Soil Science - Study Mode

[#186] Chemical formula of pyrite reclaiment is
Correct Answer

(D) FeS 2

Explanation

Solution: The mineral pyrite or iron pyrite also known as fool's gold, is an iron sulphide with the chemical formula FeS 2 . 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.

[#187] Under low N supply, tillering in plants
Correct Answer

(B) Increases

[#188] Law of limiting factor is given by
Correct Answer

(A) Blackman

Explanation

Solution: 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.

[#189] Specific Surface of a spherical soil particle having 1.5 mm diameter is
Correct Answer

(C) 4

Explanation

Solution: 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.

[#190] Cat Clay or Acid Sulphate soils found in Kerala is known as
Correct Answer

(D) Both A and B

Explanation

Solution: 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.