Soil Science - Study Mode

[#506] Gypsum is an important amendment for problem of alkaline soils widely occurs in the state of
Correct Answer

(B) Rajasthan

Explanation

Solution: Gypsum is an important amendment to the problem of alkaline soils widely occurring in the state of Rajasthan . Gypsum is a soft sulphate mineral composed of calcium dehydrate. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard, or sidewalk chalk. Gypsum is a common mineral, with thick and extensive sedimentary rocks.

[#507] The rate of weathering is generally high in
Correct Answer

(C) Humid tropical climate

Explanation

Solution: The rate of weathering of rocks depends on the composition of the rock, the climate of the area, the topography of the land and the activities of humans, animals and plants. The rate of weathering is generally high in a humid tropical climate, because of the combination of high heat and heavy rainfall. Generally, hot wet climates accelerate chemical weathering while cold dry climates accelerate physical weathering.

[#508] Phosphorus fixation occurs in soil by means of
Correct Answer

(D) All of the above

Explanation

Solution: Phosphorus fixation refers to the conversion of the phosphorus element into a fixed compound or absorbed by plants that are further unavailable for use. It occurs in soil using: Intercrystalline adsorption- adsorption of phosphate takes place on the surface of constant charge which interacts with phosphorus mainly through the cations held tightly to their plate-like surfaces and on the surfaces of variable charge. Isomorphous substitution- through this process the mechanism of the phosphate fixation is by the replacement with hydroxyl or silicate anions up to a certain amount of silicate released from the tetrahedrons. Double decomposition- based on the solubility product principles, a variety of reactions is significant in the fixation of soluble phosphates. However, the formation of insoluble precipitates of the phosphatic compound will depend on the pH of the system.

[#509] Molybdenosis, a disease in cattle, is caused by an imbalance of Mo and Cu in the diet, when Mo content of the forage is greater than . . . . . . . .
Correct Answer

(A) 5 ppm

Explanation

Solution: Molybdenosis, a disease in cattle, is caused by an imbalance of Mo and Cu in the diet when the Mo content of the forage is greater than 5 ppm. Molybdenosis is a disease of ruminants, especially cattle, caused by dietary intake of excessive molybdenum with resultant copper deficiency characterized by persistent diarrhea and, especially around the eyes, a fading of coat pigment.

[#510] The water is available between the 15 atm and
Correct Answer

(A) $$frac{1}{3}$$ atm

Explanation

Solution: Soil moisture is defined as force per unit area that must be exerted to extract water from the soil. Soil moisture tension is usually expressed in terms of atmosphere. For a given soil, soil moisture tension is inversely proportional to water content in the soil. In soil, water is available between the 15 atm and $$frac{1}{3}$$ atm.