Soil Science - Study Mode

[#391] Nitrogen loss from urea application in paddy field is known as
Correct Answer

(A) Denitrification

Explanation

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.

[#392] Which type of soil survey use the lowest categories of taxonomic and mapping units, i.e., types and phases
Correct Answer

(A) Detailed survey

Explanation

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.

[#393] Due to Nitrification process soil pH
Correct Answer

(B) Decreases

Explanation

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.

[#394] Single super phosphate has chemical composition
Correct Answer

(C) Ca (H 2 PO 4 ) 2

Explanation

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(H 2 PO 4 ) 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.

[#395] The rhizosphere effect can be quantitatively represented by
Correct Answer

(C) R : S ratio

Explanation

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.