Lesson 32 Mineral Cycling - Alaska Geobotany Center

A sedimentary cycle: the phosphorus cycle
• Marine sediments and
volcanic apatite are the
source of P in phosphate
rocks and soils.
• P is taken up by plants as
H 2 PO - 4 or HPO -2 4 , where it
becomes a component of
energy-carrying phosphate
compounds (ATP and ADP),
nucleic acids, several
essential coenzymes, and
phospholipids.
http://arnica.csustan.edu/carosella
/Biol4050W03/figures/phosphoru
s_cycle.htm
• Chemical erosion has
reduced P 2 O 5 content of
midwest soils by 36% in the
last 50 y.
Odum and Odum 1959