Phosphorus Cycle

• This cycle is not found in the atmosphere, it is 100% geological (rocks).
• This is the longest cycle.
• There are 4 steps in the phosphorus cycle.
• The 1st step- Weathering: breaking down of rocks with weather. It takes thousands of years to break down. It breaks down into soil with water and wind.
• The second step - Absorbtion: plants absorb phosphorus from soil via roots or animals eating plants.
• The 3rd step - Decomposition: releases when plants/animals die.
• The 4th step - Sediments: breaks down to the bottom of the ocean.
• Geological Uplift: turns into mountains (takes millions of years).
• Humans rely on the Absorbtion and Decomposition steps.
• Humans can affect the cycle by adding commercial inorganic fertilizer. Excess water enters causing eutrophication. When it enters the water cycle, it causes acid rain.
• Humans can affect the cycle by removing phosphorus from the cycle for fertilizer because it spends a long time in the water and oceans.