Soil Science - Study Mode
[#421] Solodization refers to the removal of . . . . . . . . from the exchange sites
Correct Answer
(C) Na +
Explanation
Solution: Solodization also known as dealkalization is the process of gradual removal of sodium ions from the exchange sites. It is nothing but the leaching of sodium from the upper soil horizons to remove alkalis. The sodium ions from the exchange sites can be removed by adding Gypsum to the soil. This process involves the dispersion of clay.
[#422] Calcium cynamide is a/an
Correct Answer
(B) Amide fertilisers
Explanation
Solution: Calcium cyanamide is an amide fertilizer. It is an inorganic compound with the formula CaCN 2 . It is the calcium salt of the cyanamide anion. In contact with water, it decomposes and liberates ammonia. This chemical is used as fertilizer and is commercially known as nitrolime. It was first synthesized in 1898 by Adolph Frank and Nikoden Caro.
[#423] Pressure membrane apparatus is used to measure matric potential moisture content relations at potential values as low as
Correct Answer
(C) 100 bar
Explanation
Solution: Pressure membrane apparatus is used to measure matric potential moisture content relations at potential values as low as 100 bar. Application of specific potential to set samples, their soil water contents are determined gravimetrically. Saturated soil samples are placed on a semi-permeable cellophane membrane with microscopic pores. This membrane allows the passage of water from the sample but retains the air pressure applied to the upper surface of the membrane.
[#424] Which one is self-indicator?
Correct Answer
(B) KMnO 4
Explanation
Solution: Potassium permanganate (KMnO 4 ) is the self-indicator among the following options. The self indicator is the chemical substance that can indicate the presence of the specific substance in the solvent mixture as a colour change at the end of the titration. Potassium permanganate is a flexible and potent oxidant that can be used by overt or indirect titration to classify many compounds.
[#425] Who gave the statement 'water was the sole nutrient of plants'
Correct Answer
(D) J. V. Helmont
Explanation
Solution: Jan Van Helmont gave the statement,” Water was the sole nutrient of plants”. He demonstrated that plants do not simply take up the soil as they grow and concluded that water was the sole source of the increased weight of the plant. He was the first to use a quantitative and ingenious experimental approach to show that plants obtain nutrition from the nutrients in the water.