Q. In case of which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrient to enter the cycle?

[A] Carbon cycle

[B] Nitrogen cycle

[C] Phosphorus cycle

[D] Sulphur cycle

Answer: C

Why this question:  

  • Important static topic: Biogeochemical cycles 
  • Recently, the Government has prepared an Action Plan to make India Aatmanirbhar in Rock Phosphate, the key raw material of DAP and NPK Fertilisers 

Ans) c 

Exp) Option c is correct. 


Option c is correct. Carbon and Nitrogen cycle are the gaseous cycles. Here, the main reservoir of nutrient is the atmosphere or the hydrosphere. In sulphur cycle, nutrient is released by weathering of rocks, erosional runoff and decomposition of organic matter. The sulphur cycle is mostly sedimentary but two of its compounds hydrogen sulphide (H2S) and sulphur dioxide (SO2) add a gaseous component to its normal sedimentary cycle. 

In Phosphorus cycle, nutrients got released mainly by weathering of rocks since the Phosphorus mainly occurs as a mineral in phosphate rocks. It enters the cycle from erosion and mining activities.  

Source) Shankar Ias Book chapter-2 page-19, 20 

Subject) Environment