Final answer:
The phosphorus cycle involves the movement of phosphorus as the phosphate ion through the environment, including weathering, use of fertilizers, excretion, dissolution in water, and geologic processes.
Step-by-step explanation:
The phosphorus cycle is a biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Phosphorus typically exists in nature as the phosphate ion (PO4³-). The primary steps in the phosphorus cycle, in order, are as follows:
- Weathering of rocks, whereby phosphate is released into the soil, water, and air.
- Use of fertilizers, which can add phosphate to the soil.
- Excretion and Decomposition of organic matter, which returns phosphate to the soil.
- Movement of dissolved phosphates into aquatic food webs and eventually into the ocean.
- Geologic uplift, where sediment is lifted, over geologic time, exposing new phosphate-rich rock.
The cycle is crucial for life as phosphorus is a key component of DNA, RNA, ATP, and phospholipids, among other biological molecules. Human influence, especially through the use of fertilizers, has significant impacts on the natural phosphorus cycle.