Soil Science - Study Mode
[#541] Cellulose decomposing bacteria are
Correct Answer
(D) All of the above
Explanation
Solution: Cellulose decomposing bacteria are Cytophaga, Angiococcus and Polyngium. Microorganisms that can produce cellulase enzymes for the degradation of cellulose are cellulose decomposing organisms. Cytophaga is a genus of gram-negative, gliding, rod-shaped bacteria and it rapidly digests crystalline cellulose C.
[#542] Which of the following nutrient elements is responsible for resistance to plant disease?
Correct Answer
(D) K
Explanation
Solution: Potassium is the nutrient element responsible for resistance to plant disease. Disease resistance is the ability to prevent or reduce the presence of diseases in otherwise susceptible hosts. And potassium is an essential element for plant growth it is important to food crops. It helps use water and resist drought and enhances fruits and vegetable production.
[#543] Select the correct sequence of weathering stages in soil formation
Correct Answer
(C) Initial - juvenile - virile - senile - final
Explanation
Solution: The correct stages of a sequence of weathering stages in soil formation are: Initial - Juvenile - virile - senile - final. Mohr and Van Baren have differentiated soil formation into 5 stages. Initial - The un-weathered parent rock. Juvenile - weathering just started. Virile - Easily weatherable minerals have been decomposed for the greater part and the clay content has increased. Senile - decomposition is on the verge of completion. Final - soil formation has been completed, the parent material is completely weathered.
[#544] For Upper plastic Limit / Liquid Limit pF value is
Correct Answer
(B) 0.5
Explanation
Solution: The liquid limit (LL) or upper plastic limit is the e-water content at which the soil changes from a liquid state to an aplastic state. The pF value is a quantity that indicates the quality of water contained in the soil. A pF value near 0 indicates that the soil is filled with water. For the upper plastic limit or liquid limit, the pF value is 0.5.
[#545] Salt index is given by
Correct Answer
(A) Puri
Explanation
Solution: The salt index is a numeric ratio of the increase in osmotic pressure produced by a selected fertilizer product compared to that produced by the same weight of sodium nitrate, where sodium nitrate is assigned a relative value of 100. The salt index is given by Puri .