Soil Science - Study Mode
[#881] Principle factors governing K fixation in clay lattice are
Correct Answer
(C) Both A and B
Explanation
Solution: Principle factors governing K fixation in clay lattice are Both Ionic radii as well as Hydration energy. Potassium ions and other cations are readily fixed because they have relatively low energies of hydration. Fixation occurs when K is held in highly charged sites in the interlayer region of vermiculite and mica minerals. This differs from exchangeable K which is held at lower charged sites, on the surface and edges of clay minerals.
[#882] Gypsum Requirement of gypsum is
Correct Answer
(B) 1
Explanation
Solution: The amount of gypsum required by soil is known as the gypsum requirement. Gypsum is a soft sulphate mineral composed of calcium sulphate dihydrate. Gypsum is one of the earliest forms of fertilizer. Gypsum is a moderately soluble source of the essential plant nutrients, calcium and Sulphur, and can improve overall plant growth. Gypsum Requirement of Gypsum is 1.
[#883] The B horizon is generally absent in
Correct Answer
(A) Black soils
Explanation
Solution: The B horizon is generally absent in Black soils. Black soils are young soils or soils highly resistant to weathering and it usually lacks a B horizon. Black soils are mineral soils that have a black surface horizon, enriched with organic carbon that is at least 25 cm deep. It is very fertile soil rich in humus and nutrients.
[#884] A soil, which has pH more than 8.5 and ESP more than 15 and EC is greater than 4 m mhos/cm, the soil is called
Correct Answer
(C) Saline alkaline soil
Explanation
Solution: A soil, which has a pH of more than 8.5 and ESP of more than 15 and EC is greater than 4 m mhos/cm, the soil is called saline-alkaline soil. ESP is Exchangeable sodium percentage and it measures the proportion of cation exchange sites occupied by sodium. Soil Electrical Conductivity (EC) is a measure of the number of salts in the soil. it is an excellent indicator of nutrient availability and loss, soil texture and available water capacity.
[#885] Earthworm cast is rich in which nutrient?
Correct Answer
(A) Ca
Explanation
Solution: Earthworm casts are the indurated soil material surrounding channels left in the soil by earthworms. The earthworm castings help increase soil’s water retention, improve soil aeration, anchor plant nutrients and boost soil fertility. The casting of earthworms is rich in Calcium along with nitrogen, potassium, phosphorus and magnesium.