Phosphorus

P biological uses

cell walls, DNA, RNA, ATP

P industrial uses

fertiliser, fire retardant, organophosphorus, matches

P water reservoirs → plants & animals

assimilation

P plants & animals → soil

death & excretion

P soil → deep-sea sediment

surface leaking & precipitation

P deep-sea sediment → sedimentary rock

mineralisation & tectonic activity

P sedimentary rock → water reservoir

weathering & erosion

P cycle components

• organic P

• soil solution P

• secondary compounds

• mineral surfaces

• primary materials

P input to soil

• animal manure

• plant residues

• atmospheric deposition

• mineral fertilisers

P losses from soil

• crop harvest

• leaching

• runoff & erosion

• plant uptake

P units

terra grams

determines form of available P

pH

P in acid soils (low pH)

• iron & aluminium binding

• becomes immobilised

P in basic soils (high pH)

• calcium binding

• forms apatite (immobilised)

pH with most available P?

pH 6-7

P sedimentary rock → water reservoirs

weathering & erosion

P water reservoirs → plants & animals

assimilation

P plants & animals → soil

death & excretion

P soil → deep sea sediment

leaking & precipitation

P deep sea sediment → sedimentary rock

mineralisation & tectonic activity