Soil Science - Study Mode
[#521] Feldspar is a
Correct Answer
(A) Primary mineral
Explanation
Solution: Feldspar is the primary mineral and group of naturally occurring aluminosilicate minerals containing varying amounts of potassium, sodium, calcium or lithium which occur in igneous rocks. Feldspars make up about 60% of the earth's crust, 41% of the Earth's crust and 41% of the Earth's continental crust by weight.
[#522] The use of balanced fertiliser use is most desirable because it
Correct Answer
(B) Corrects all deficiencies
Explanation
Solution: The use of balanced fertilizer use is most desirable because it corrects all deficiencies. A balanced fertilizer is a fertilizer that has three numbers that are about the same, like a ratio of 10 : 10 : 10. Balanced application of fertilizers enhances fertilizer use efficiency and leads to an increase in crop yields by improving the physical, chemical and biological environment of the soil.
[#523] The chemical composition of basic slag is
Correct Answer
(B) (CaO) 3 P 2 O 5 , SiO 2
Explanation
Solution: Basic slag is low in silica and high in base-forming oxides that are used in the basic process of steelmaking and that are subsequently useful as a fertilizer. A basic slag contains oxides like MgO and CaO, which makes the slag thicker. The chemical composition of basic slag is (CaO) 3 P 2 O 5 , SiO 2 .
[#524] The particle density of normal soil is
Correct Answer
(C) 2.65 gm/cm 3
Explanation
Solution: The particle density of normal soil is 2.65 gm/cm 3 . It is defined as the mass of a unit volume of sediment solids. Particle density is the density of the solid particles that collectively make up a soil sample. The value is commonly expressed in grams per cubic centimeter.
[#525] Bacteria Population constitute how much . . . . . . . . % of Organic matter.
Correct Answer
(C) 2 - 4%
Explanation
Solution: The bacterial population constitutes 2 - 4% of organic matter. Soil organic matter is the organic component of soil, consisting of three primary parts including small and fresh plant residues, small living soil microorganisms, decomposing active organic matter and stable organic matter. Soil organic matter is the primary source of carbon which gives energy and nutrients to soil organisms.