1. Storage as Plant Products, Feeds, Mineral Supplements CROPS
Phosphorus Cycle
Storage as Plant Products, Feeds, Mineral Supplements
Mineral Fertilizers
Surface Runoff, Wind Erosion, Leaching (sandy soils, low OM, Na and K phosphates)
Non labile P
80-90% of total soil P
Labile P
Soil Solution P ~
0.01% of total soil P
P sorbed to clays
and to Al, Fe oxides
Fe, Al,
Mn, Ca, Mg
phosphates that have aged
and formed rigid
crystal structures
Stable organic phosphates
Surface-adsorbed PO 4 s
Newly-precipitated
Fe, Al, Mn phosphates
on acid soils;
Ca, Mg phosphates on
alkaline soils H 2
- and HPO4=
ions released from
labile forms of P or
added via fertilizers
CROPS
ANIMALS, HUMANS
SOIL
Microbial Decomposition
Plant Roots
Mycorrhiza
Microbial
Storage as Animal and Human Excrement