The most important climatic factors that regulate decomposition through their effects on the activities of soil microbes are:
(A) Sunlight
(B) Temperature
(C) Soil moisture
(D) Pressure
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (B) and (C) only
Decomposition is the breakdown of dead organic matter (detritus) into simple inorganic substances by soil microbes. So any climatic factor that speeds up or slows down these microbes changes the rate of decomposition.
(A) Sunlight — Incorrect. Soil microbes do not need sunlight. Decomposition goes on in the dark, inside the soil.
(B) Temperature — Correct. Microbes work faster in warm conditions. Low temperature slows them down, so organic matter builds up.
(C) Soil moisture — Correct. A moist soil favours decomposition. In waterlogged soil there is no oxygen (anaerobiosis), and decomposition slows down.
(D) Pressure — Incorrect. Pressure is not a climatic factor that controls decomposition.
NCERT Extract:
Decomposition – …
