Phosphorus Cycle Geochemical Cycles continued Objectives Describe the

Phosphorus Cycle Geochemical Cycles continued

Objectives: Describe the process of cycling phosphorus throughout environment. Describe the role that fertilizer plays in both the nitrogen and phosphorus cycle.

What is phosphorus? • An element [P] that forms molecules that make up the cells of living organisms • Helps form bones and teeth in animals

How do organisms get P? • Plants: get P from soil and water • Animals: get P from eating the plants Phosphorus cycle: movement of phosphorus from the environment to organisms and then back to the environment.

Phosphorus cycle • Occurs very slowly • Doesn’t occur in atmosphere because P is rarely a gas.

How does P get in soil and water? • 1 st way: rocks erode and small amounts of P dissolve in soil and water • Plants absorb P in the soil through roots • 2 nd way: Excretion, death and decomposition • 3 rd way: washes off the land into oceans – Phosphate salts-don’t dissolve in water-accumulate at bottom

How can too much N or P effect an ecosystem? • Fertilizers contain both Nitrogen and Phosphorus to stimulate faster plant growth • What happens when there is an excessive amount of fertilizer used?

Overuse of fertilizer… • Excess fertilizer can enter terrestrial and aquatic ecosystems through runoff • Causes rapid growth of algae -Algal bloom • Algal blooms can deplete ecosystems of nutrients like oxygen & kill organisms