Which of these is not a correct difference between carbon cycle and phosphorus cycle ?

Options

A. Carbon cycle is gaseous type of nutrient cycle while phosphorus cycle is a sedimentary type of nutrient cycle.
B. The reservoir of carbon is ocean while the reservoir of phosphorus is rock
C. In carbon cycle , there is respiratory release of carbon into atmosphere while this doesn't happen in phosphorus cycle
D. Atmospheric inputs of phosphorus through rainfall are much larger than carbon inputs

Answer

To determine which of the provided statements is not a correct difference between the carbon cycle and the phosphorus cycle, we will analyze each statement step by step.

### Step-by-Step Solution:

1. **Understanding the Carbon Cycle**:
- The carbon cycle is primarily a gaseous nutrient cycle. Carbon exists in the atmosphere as carbon dioxide (CO2) and is exchanged between the atmosphere, oceans, and living organisms.

**Hint**: Remember that the carbon cycle involves processes like photosynthesis and respiration, which release and absorb gases.

2. **Understanding the Phosphorus Cycle**:
- The phosphorus cycle is considered a sedimentary nutrient cycle. Phosphorus is not found in a gaseous state in the atmosphere; instead, it is primarily found in rocks and soil.

**Hint**: Focus on the fact that phosphorus does not have a significant gaseous phase in its cycle.

3. **Reservoirs of the Nutrients**:
- For the carbon cycle, the ocean acts as a major reservoir of carbon. Approximately 71% of the Earth's carbon is stored in the oceans.
- For the phosphorus cycle, the primary reservoir is rocks, as phosphorus is released from weathering of these rocks into the soil and water.

**Hint**: Identify the main storage locations for each nutrient in their respective cycles.

4. **Respiratory Release**:
- In the carbon cycle, carbon is released into the atmosphere through respiration by living organisms, which produce carbon dioxide.
- In contrast, the phosphorus cycle does not involve a respiratory release of phosphorus, as it does not exist in a gaseous state.

**Hint**: Think about how living organisms contribute to the carbon cycle versus the phosphorus cycle.

5. **Atmospheric Inputs**:
- The statement claims that atmospheric inputs of phosphorus through rainfall are much larger than carbon inputs. This is incorrect because phosphorus does not enter the atmosphere in significant amounts; it primarily cycles through soil and water.
- In contrast, carbon does enter the atmosphere through various processes, including respiration and combustion.

**Hint**: Consider how each nutrient enters the atmosphere and the scale of those inputs.

### Conclusion:
Based on the analysis, the statement that "atmospheric inputs of phosphorus through rainfall are much larger than the carbon input" is the incorrect difference between the carbon cycle and the phosphorus cycle. Therefore, this statement is not a correct difference.

**Final Answer**: The statement that is not a correct difference is: "Atmospheric inputs of phosphorus through rainfall are much larger than the carbon input."