nutrient cycles - phosphorus cycle

what is mycorrhize?

• fungi that form symbiotic relationships with the roots of plants

• they help the plants absorb inorganic ions and water from the soil

what is mycorrhizae made up of?

• thin, long strands called hyphae, which connect to the plant’s roots

what does the hyphae do?

• increases the surface area of the plant root system

• this helps plants take up ions that are in short supply, such as phosphorus, and water at a faster rate

steps of the phosphorus cycle?

• phosphate ions in rocks are released into the soil by weathering

• phosphate ions are taken into the plants through the roots

  • mychorrhizae greatly increase the rate at which phosphorus can be assimilated

• phosphate ions are transferred through the food chain as animals eat the plants and in turn are eaten by other animals

• phosphate ions are lost from animals in waste product

• when plants and animals die, saprobionts are involved in breaking down the organic compounds, releasing phosphate ions into the soil for assimilation by plants

  • these microorganisms also released the phosphate ions from urine and faeces

• weathering of rocks also releases phosphate ions into seas, lakes and rivers.

• this is taken up by aquatic producers, such as algae, and passed along the food chain to birds

• the waste produced by sea birds is known as guano and contains a high proportion of phosphate ions

  • guano returns a significant amount of phosphate ions to soils (particularly in coastal areas)

  • it is often used as a natural fertiliser