Final answer:
Phosphorus is mostly found in non-living things, while carbon and nitrogen are found in both living and non-living things. Phosphorus is not present in significant amounts in the atmosphere. Phosphorus is cycled through weathering and erosion, while carbon and nitrogen are cycled through biological processes.
Step-by-step explanation:
One key difference between the phosphorus cycle and the carbon and nitrogen cycles is that phosphorus is mostly found in non-living things whereas carbon and nitrogen are found in both living and non-living things. Phosphorus is not present in significant amounts in the atmosphere, unlike carbon and nitrogen which are found in the atmosphere in various forms. Phosphorus is primarily cycled through weathering and erosion, while carbon and nitrogen are cycled through biological processes such as photosynthesis, respiration, and decomposition.