In phosphorus cycle phosphorus is mainly added to the cycle by

Options

A. volcanic gases
B. decomposers
C. Weathering
D. Rain water

Answer

**Step-by-Step Solution:**

1. **Understanding the Phosphorus Cycle**: The phosphorus cycle describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike other biogeochemical cycles, phosphorus does not have a gaseous phase under normal conditions.

2. **Identifying the Main Reservoir**: The primary reservoir of phosphorus in the cycle is found in rocks, specifically in the form of phosphate minerals.

3. **Weathering Process**: The cycle begins with the weathering of these phosphate rocks. Weathering is the process that breaks down rocks, releasing phosphorus into the soil.

4. **Phosphorus Absorption**: Once released into the soil, phosphorus can be absorbed by plants. Animals then obtain phosphorus by consuming these plants.

5. **Role of Decomposers**: When plants and animals die, decomposers break them down, returning phosphorus back to the soil, but this is a secondary process in the cycle.

6. **Other Contributions**: While volcanic eruptions can also contribute phosphorus to the cycle, they are not the primary source. Acid rain can introduce small amounts of phosphorus, but again, this is not significant compared to weathering.

7. **Conclusion**: The main way phosphorus is added to the phosphorus cycle is through the weathering of phosphate rocks.

**Final Answer**: Phosphorus is mainly added to the phosphorus cycle by the weathering of rocks.

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