Phosphorus cycle and fertiliser runoff

BiologyCell BiologyCommunity

A box-and-arrow model of the phosphorus cycle through rocks, soil, plants, animals, a lake, the ocean and sediments. Arrow thickness shows the flow per year and box fill shows the amount stored. Change fertiliser, rainfall, shore plant cover and weathering to see how much phosphate reaches the lake and how algae and oxygen respond.

Lesson: Phosphorus has no gas phase, so it moves only through rock, soil, living things and water. Natural flows such as weathering are slow, and much of the phosphorus ends up locked in ocean sediments until uplift turns them back into rock over millions of years. Fertiliser adds extra phosphate to the soil. Rain washes some of it into lakes, where it feeds algae. When the algae die, decomposers use up the oxygen in the water. Plants along the shore reduce runoff. Phosphate stored in the lake mud keeps being released for years, so a lake recovers slowly.

Created by a teacher with Simulic AI and reviewed by the Simulic team.