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Soil Science MCQ Question and Answer | Agriculture MCQ Question

Soil Science MCQ Question and Answer with easy explanations in Agriculture mcq. Soil Science MCQ section is suitable for aspirants preparing for IBPS- AFO (Agriculture Field Officer) Iffco, Kribhco, NFL, NSC, ICAR-JRF/SRF/ ARS, IARI, SADO, DDA,ADA,FCI,ASRB,B.Sc Agriculture and M.SC Agriculture. Page-10 section-5

Each section contains 100 MCQs on Soil Science .
91
Concentration of nitrogen in soil air is
Discuss
Answer & Solution
Answer: Option C
Solution:
Our environment is the air around us. Earth’s atmosphere is made up of five main gases, nitrogen, oxygen, water vapour, argon and carbon dioxide.
The concentration of nitrogen in soil air is 78%. And the other major component of air is 21% of oxygen.
92
Main difference between Soil profile and pedon
Discuss
Answer & Solution
Answer: Option A
Solution:
The soil profile is the vertical section of the soil from the ground surface downwards to where the soil meets the underlying rock. Whereas a pedon is a sample of a body of soil that is 1 m2 at the surface and extends to the bottom of the soil.
A soil profile is smaller than a pedon.
A soil profile is 2-D whereas a pedon is 3-D.
93
Which nitrogenous fertilizer industrially made first?
Discuss
Answer & Solution
Answer: Option D
Solution:
Calcium cyanamide (CaCN2) is the nitrogenous fertilizer industrially made first. It is commercially known as Nitrolime. It was first synthesized in 1998 by Adolph Frank and Nikodem Caro.
It is an inorganic compound with calcium salt of the cyanamide anion that is widely used as fertilizer. In contact with water, it decomposes and liberates ammonia.
94
Saline soils are managed by
Discuss
Answer & Solution
Answer: Option D
Solution:
Saline soils are managed by the leaching of soluble salt. It is done by the application of water in excess quantities than the need of plants and this method is termed as leaching requirement method.
Managing the salinity involves striking a balance between the volume of water entering (recharge) and leaving (discharging) the groundwater system.
95
Nitrogen loss from urea application in paddy field is known as
Discuss
Answer & Solution
Answer: Option A
Solution:
Nitrogen loss from urea application in the paddy field is known as Denitrification.
Denitrification in paddy soils is an environmentally important reaction, which reduces leaching or emission of nitrogen pollutants. It is the process that converts nitrate to nitrogen gas, thus removing bioavailable nitrogen and returning it to the atmosphere.
96
Which type of soil survey use the lowest categories of taxonomic and mapping units, i.e., types and phases
Discuss
Answer & Solution
Answer: Option A
Solution:
A detailed survey is the elaborated mapping of soil survey that use the lowest categories of taxonomic and mapping units, i.e. types and phases, which are genetically quite homogenous.
The main objective of a soil survey is to get information about the soil genesis and provide information about the soil resources of the area.
97
Due to Nitrification process soil pH
Discuss
Answer & Solution
Answer: Option B
Solution:
Due to the nitrification process soil pH Decreases.
As the ammonium -N in fertilizers undergoes nitrification i.e. conversion of ammonium to nitrate in soils by bacteria, hydrogen (H+) is released, which can increase acidity. As the percentage of ammonium increases in a given fertilizer, the acidifying potential will also be increased, thus reducing pH.
98
Single super phosphate has chemical composition
Discuss
Answer & Solution
Answer: Option C
Solution:
SSP (single super phosphate), a multi nutrient fertilizer containing Phosphorus (14.5%), Sulphur (11%) and calcium (21%).
The chemical formula of SSP is Ca(H2PO4)2. It is applied as a basal fertilizer with other chemicals and organic fertilizers. It has a tremendous impact on plant growth and also assists in maintaining soil health and protection against pests and diseases.
99
The rhizosphere effect can be quantitatively represented by
Discuss
Answer & Solution
Answer: Option C
Solution:
The rhizosphere effect can be quantitatively represented by the R : S ratio.
The term rhizosphere to soil ratio indicates the number of microbes in rhizospheric soil divided by the number of microbes in soil free of plant roots. R:S ratio is greater for bacteria (20 : 1) and less for fungi and actinomycetes.
100
One ton is equal to (kg)
Discuss
Answer & Solution
Answer: Option B
Solution:
The ton is a unit of measure principally a unit of weight. It is also used informally to mean a large amount of any material.
In the United Kingdom, the Imperial ton is a statute measure and defined as 2,240 pounds (about 1016 kg).
In the United States and Canada, a ton is defined to be 2000 pounds i.e. equals 907 kg.