Phosphorus Cycle

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Phosphorus Cycle
Environmental Plant Phys.
Amanda Kevin Sarah
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Phosphorus

• P is a common element found all around us.
• Present in lakes, streams, oceans, soil, rocks,
  animals, and plants.

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Phosphorus in Plants

• P is one of 17 essential nutrients for plant
  growth.
• Nitrogen and potassium are the only other
  essential plant nutrients taken up in greater
  amounts.

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Importance of Phosphorus

• P is integral in plant metabolism and ATP
  production, as well as forming the backbone of
  DNA and RNA.
• P plays an essential role in the Calvin Cylce and
  the conversion of sunlight to useable forms of
  energy (glucose).

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Calvin Cycle
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The P Cycle

• Describes the process by which P travels through
  the lithosphere, hydrosphere, and biosphere.
• Unique in that P is rarely found in the
  atmosphere.

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Origin of Phosphorus

• P is present in rocks as well as in salts in
  ocean sediments.
• Over time weathering releases P from rocks where
  it finds its way into the soil and water.

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P Cycle and Life

• From the soil and water P is taken up by plants
  and algae.
• P then travels up the food chain going from
  consumer to consumer.
• P finds its ways back into the soil and water
  through excretion by consumers and the finals
  decomposition of organisms.

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The P Cycle and Humans

• Phosphate is mined and used to make fertilizer,
  which may be applied to farmers soil.
• Corn that is grown there may be used to feed
  cattle.
• Part of phosphate from the roots of the corn
  plants absorbed end up in feedlot wastes, which
  is usually used as fertilizer and washed into
  rivers.
• Beef from cattle may be consumed by people, where
  it ends up in human waste and flushed into sewer
  systems.
• To make up for steady loss of phosphate from
  land, farmers add phosphate fertilizer to fields.

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Human Impact

• When P finds its way into waterways in large
  amounts, as result of runoff from the use of
  fertilizers, it can greatly contribute to
  eutrophication.
• The process of eutrophication causes excessive
  growth of water plants and algae, thus depleting
  oxygen levels and suffocating fish and other
  aquatic fauna.

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SOURCES
www.ikzm-d.de/abbildungen/59_phosphoruscycle.gif
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basics.html http//www.enviroliteracy.org/article
.php/480.html http//www.ppi-far.org/ppiweb/ppiba
se.nsf/webindex/article88446F25852568F20064198A1
48EEE97 http//arnica.csustan.edu/carosella/Biol4
050W03/figures/phosphorus_cycle.htm http//en.wik
ipedia.org/wiki/Phosphorus_cycle