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?

The correct answer is Option 3

Key Points

• Phosphorus cycle:
  • The Phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere.
  • Phosphorus moves in a cycle through rocks, water, soil and sediments and organisms.
  • Over time, rain and weathering cause rocks to release phosphate ions and other minerals.
  • This inorganic phosphate is then distributed in soils and water.  Hence, Option 3 is correct.
  • Plants take up inorganic phosphate from the soil.
  • Phosphorus is an essential nutrient for animals and plants.
  • It plays a critical role in cell development and is a key component of molecules that store energy, such as ATP (adenosine triphosphate), DNA and lipids.
• The global phosphorus cycle includes four major processes:
  • Tectonic uplift and exposure of phosphorus-bearing rocks such as apatite to surface weathering.
  • Physical erosion, and chemical and biological weathering of phosphorus-bearing rocks to provide dissolved and particulate phosphorus to soils, lakes and rivers.
  • Riverine and subsurface transportation of phosphorus to various lakes and run-off to the ocean.
  • Sedimentation of particulate phosphorus (e.g., phosphorus associated with organic matter and oxide/carbonate minerals) and eventually burial in marine sediments.