Soil Science - Study Mode
[#221] Percent pore space can be calculated by using of which formula
Correct Answer
(B) $$\% { ext{PS}} = { ext{100}} - left( {frac{{{{ ext{D}}_{ ext{b}}}}}{{{{ ext{D}}_{ ext{p}}}}} imes 100}
ight)$$
Explanation
Solution: Percent pore space is defined by the porosity of a material possessing free space between the mineral grains expressed in percentage. It is proposed by Rebollo et al., 1996. It depends on the size and sorting of the particles as a cubic or hexagonal package. $$\% { ext{PS}} = 100 - left( {frac{{{{ ext{D}}_{ ext{b}}}}}{{{{ ext{D}}_{ ext{p}}}}} imes 100}
ight)$$
[#222] Walkley & Black method is associated with
Correct Answer
(B) Org.C
Explanation
Solution: Walkley & Black method is associated with soil organic Carbon. It helps in determining carbon. This method quantifies the amount of oxidizable organic matter in which OM is oxidized with a known amount of chromate in the presence of Sulphuric acid. The remaining chromate is determined spectrophotometrically at 600 nm wavelength.
[#223] Which soil order derived from volcanic ejecta and dominated by allophane
Correct Answer
(B) Andisols
Explanation
Solution: Andisols are derived from volcanic ejecta and are dominated by allophane. Andisols are an essential tool for agriculture and can be used to cultivate sugarcane, tobacco, potatoes, tea, vegetables, wheat, rice and other crops. These soils also sustain fragile ecosystems in the Andes mountains from forests to paramos, helping to provide essential nutrients and regulate the water cycle.
[#224] Acidulation process is associated with
Correct Answer
(A) Nitrophosphate
Explanation
Solution: In the acidulation reaction process, phosphoric acid is produced by reacting sulphuric acid with phosphate rock. This process is associated with nitrophosphate . It should be mentioned that this reaction takes place in the presence of an excessively large amount of H 3 PO 4 .
[#225] Which index proved to be useful to assess the dominating type of clay mineral in soil proposed by Martin and Russell
Correct Answer
(A) Y-index
Explanation
Solution: Y-index is proved to be useful to assess the dominating type of clay mineral in soil proposed by Martin and Russell. An index is defined as a numerical value describing the relative status of a population on a graduated scale with definite upper and lower limits, which permits and facilitates comparison with other groups classified by the same criteria & method.