Institute Food Agricultural Sciences (IFAS ......6/22/2008 WBL 9 [50%] 1996 Florida 2003 North...

1

Biogeochemistry of WetlandsS i d A li tiS i d A li ti

Institute of Food and Agricultural Sciences (IFAS)

Science and ApplicationsScience and Applications

Wetland Biogeochemistry LaboratorySoil and Water Science Department

Phosphorus Cycling Processes Phosphorus Cycling Processes

6/22/2008 WBL 16/22/2008 16/22/2008 WBL 1

InstructorK. Ramesh [email protected]

Soil and Water Science DepartmentUniversity of Florida

Phosphorus Cycling ProcessesInstitute of Food and Agricultural Sciences (IFAS)

PPPP

PPPPDRPDRP

DRPDRP

Water columnWater column

6/22/2008 WBL 26/22/2008 WBL 2

PPPPDRPDRPSoilSoil

2

Topic Outline

Phosphorus Cycling Processes

Water Column

IntroductionForms of phosphorusInorganic Phosphorus retention mechanismsOrganic phosphorus dynamicsPhosphorus exchange between soil and overlying water columnRegulators of phosphorus reactivity and

Soil

6/22/2008 WBL 36/22/2008 3

Regulators of phosphorus reactivity and mobilityPhosphorus memory in wetlands

Learning Objectives

Id tif d i i d i f f


Identify sources, and inorganic and organic forms of phosphorusInorganic phosphorus retention mechanisms in soilDescibe the influence of soil type on inorganic phosphorus retentionRole of enzymes and microorganisms in organic phosphorus mineralizationBiotic regulation phosphorus retentionPh h h b t il d l i t

6/22/2008 WBL 46/22/2008 4

Phosphorus exchange between soil and overlying water columnDraw the phosphorus cycle and indentify, storages, abiotic and biotic processes, and fluxes in soil and water column

3

TerminologyTerminologyTotal Phosphorus (TP) Dissolved total P (DTP)

Total P in solutions filtered through 0.45 um membrane filterTotal P in solutions filtered through 0.45 um membrane filter

Dissolved reactive P (DRP) or Soluble Reactive P (SRP) Water samples filtered through 0.45 um membrane filter and analyzed for ortho-P.

Dissolved Organic P (DOP) DTP – DRP = DOP

Particulate inorganic P (PIP)

6/22/2008 WBL 56/22/2008 5

Particulate inorganic P (PIP)Particulate matter or soil extracted with acid

Particulate organic P (POP)TP-PIP = POP

Plant biomass PRunoff,

Phosphorus Cycle

AEROBIC

Peataccretion

[Fe, Al or Ca-bound P]

Litterfall

DOP DIP PIPPOP

DIP

DIP

Runoff, Atmospheric Deposition

Outflow

Periphyton P

6/22/2008 WBL 6

ANAEROBIC

accretionPIP

Ca-bound P]Adsorbed

IP

DIP

POP DOPDOP

DIP

4

Fertilizers, Animal wastesBiosolids, Wastewaters

Phosphorus Transfer

Wetlands & Streams

[sink/source]

Uplands[sink/source]

6/22/2008 WBL 7

LakeOkeechobee

Lake [sink]

Phosphorus Imports from Various Sources: Florida

69%8%

8%10% 0%

Fertilizers

AtmosphericDepositionAnimal

Manures

Wastewater

Composts (?)Natural weathering of minerals (?)

6/22/2008 WBL 8

5%Biosolids

1996Total = 61,300 mt P per year

5

Fertilizer Phosphorus Inputs

[8%]

Florida Florida 42,660 42,660

metric ton yearmetric ton year--11

[ ]

[5%]

[17%]

[20%]

North AmericaNorth America1.85 x 101.85 x 1066

6/22/2008 WBL 9

[50%]

1996 Florida2003 North America2003 World

metric tons yearmetric tons year--11

WorldWorld14 x 1014 x 1066

metric tons yearmetric tons year--11

[Mullins et al., 2005]

[Mullins et al., 2005]

Phosphorus Loads from UplandsUplands have been a steady source of P to wetlands and aquatic systems, where

b t ti l t f P h l t d isubstantial amounts of P has accumulated in soils and sedimentsBest management practices and other remedial measures can significantly reduce P loads from uplands to wetlands and aquatic systemsHow will wetlands and aquatic systems respond to P load reduction?

6/22/2008 WBL 10

to P load reduction?How long P memory lasts in wetlands and aquatic systems before they reach stable condition?

6

Capacity for storing phosphorus in

Phosphorus Memory in a Watershed

Water ColumnCapacity for storing phosphorus in various ecosystem components (uplands, wetlands, and aquatic systems)

Transient poolsStable pools

Capacity for showing effects as the result of past practices

Detritus

PP

PP

6/22/2008 WBL 11

result of past practices Length of time over which phosphorus release extends before returning to a stable condition

Soil

Phosphorus Transfer [Lake Okeechobee Basin]

Uplands (82%)

[4157]

Phosphorus BudgetUplands (82%)

[754]

[415] (10%)

[tons/year]

6/22/2008 WBL 126/22/2008 WBL 12

Wetlands& Streams

(8%) LakeOkeechobee

[415] (10%)

7

Phosphorus Gradient in Wetlands

PhosphorusOutflow

PhosphorusLoading

Gradient in nutrient enrichment insoil and water column

6/22/2008 WBL 136/22/2008 WBL 13

[ Distance from inflow]

soil and water column

150

Water column TP - WCA-2A transect

Tota

l P (µ

g/L)

50

100

6/22/2008 WBL 146/22/2008 WBL 14

0 2 4 6 8 10 12 14 160

Distance from Inflow (km)

8

Phosphorus accretion rates inEverglades WCA-2A

y-1 )

1.2AC

CU

MU

LATI

ON

(g m

-2y

0.4

0.6

0.8

1.0

6/22/2008 WBL 156/22/2008 WBL 15

P A

DISTANCE FROM INFLOW (km)0 2 4 6 8 10 12 14 16

0.2

0

Total P concentration in WCA-2A soil (0-10 cm)

1990 1998

6/22/2008 WBL 166/22/2008 WBL 16

9

Everglades – Soil phosphorus

6/22/2008 WBL 176/22/2008 WBL 17

0-40-44-8

Soil Phosphorus Blue Cypress Marsh-1992

Dep

th (c

m) 8-12

16-20

24-28

32 36

4 88-12

12-1616-2020-2424-28 Impacted

6/22/2008 WBL 186/22/2008 WBL 18

D 32-36

36-40

0 1,000 2,000

24-2832-3640-44

0 1,000 2,000Total P (mg /kg)

Unimpactedp

10

External LoadReduction

horu

s

Phosphorus Memory

Internal Memory

BackgroundLevel

r Col

umn

Pho

sph

6/22/2008 WBL 19

Lag time for Recovery

Wat

er

Time - Years

Ecological Significance –Phosphorus Loading

WATERWATER

PLANTS

Labile DETRITUSDETRITUS

N C PN C

6/22/2008 WBL 206/22/2008 WBL 20SOILP N

Microbial Biomass

N

Microbial Biomass

P

P

11


Phosphorus Cycle

AEROBIC

Peataccretion


Litterfall

DOP DIP PIPPOP

DIP

DIP


Outflow

Periphyton P

6/22/2008 WBL 21

ANAEROBIC

accretionPIP

Ca-bound P]Adsorbed

IP

DIP

POP DOPDOP

DIP

Phosphorus in Wetlands Organic

phosphorusPhosphorus Uptake by

Soil porewaterphosphorus[dissolved]

p ploading algae and

plants

Metal o ides

6/22/2008 WBL 226/22/2008 WBL 22

Metal oxidesand clay mineral

surfaces

Discretephosphate

minerals

12

Soil Phosphorus FormsInorganic PKCl Pi Bioavailable P— KCl-Pi - Bioavailable P

— NaOH-Pi - Fe-/Al- P [slowly available]

— HCl-Pi - Ca-/Mg- P [slowly available]

Organic PMicrobial Biomass P Bioavailable P

6/22/2008 WBL 236/22/2008 WBL 23

— Microbial Biomass P - Bioavailable P — NaOH-Po - Fulvic Acid -P [slowly available] — NaOH-Po - Humic Acid -P [very slowly available]— Residual P -Highly resistant [unavailable]

Phosphate ions and pHPhosphate ions and pHH3PO4 = H+ + H2PO4

- pK = 2.15H2PO4

- = H+ + HPO42- pK = 7.20

HPO42- = H+ + PO4

3- pK = 12.35

H3PO4 PO43-

Oxidation number for P

[+5] [+5]

6/22/2008 WBL 246/22/2008 WBL 24

3 4H2PO4

-

HPO42-

4

PH3

[ 5][+5][+5]

[ ][-3]

13

1 000

3,000

kg-1

) Y = 0.01X1.54

R2 =0 897; n=390

Inorganic Phosphorus-Organic Soils - WCA-2A

10

30

100

300

1,000no

rgan

ic P

(mg

k

WCA1

WCA2

WCA3

R 0.897; n 390

6/22/2008 WBL 256/22/2008 WBL 25

50 100 200 500 1,000 2,000 5,0001

3

Total Phosphorus (mg kg-1 )

Tota

l In WCA3

HWMAEAA

KCl-Pi (available)

Stream Sediments –Okeechobee Drainage Basin

2% 29%

6%

50%

13%

1%7%

10%

Fe- and Al-bound P

Alkali extractable organic P

Ca- and Mg-bound P

Residual P

DL-StreamT l P 8 P/k

6/22/2008 WBL 266/22/2008 WBL 26

71%11%

7%Total P = 877 mg P/kg

Rucks-StreamTotal P + 93 mg P/kg

14

KCl-Pi (available)<0 1%

1%

Organic Wetland Soils –Drainage Effects

1% 7%

Fe- and Al-bound P

Alkali extractable organic P

Ca- and Mg-bound P

Residual P

<0.1%4%

72%

23%

Peat Depth < 10 cmT t l P 836 P/k

6/22/2008 WBL 276/22/2008 WBL 27

24%

21%

47%

Total P = 836 mg P/kg

Peat Depth > 30 cmTotal P = 411 mg P/kg

Inorganic Phosphorus

yPore ater P

Bio

avai

labi

lity High

Low

Pore water P ExchangeableFe-/Al- bound PCa-/Mg-bound PR id l P

6/22/2008 WBL 286/22/2008 WBL 28

Residual P

15

Inorganic PhosphorusAcid soils

AlPO4 . 2H2O [Variscite]AlPO4 . 2H2O [Variscite]FePO4 . 2H2O [Strengite]

Alkaline soilsCa (H2PO4)2 [Monocalcium phosphate]Ca HPO4. 2H2O [Dicalcium phosphate]Ca8 (H2 PO4)6 . H2O [Octacalcium phosphate]

6/22/2008 WBL 296/22/2008 WBL 29

8 ( 2 4)6 2 [ p p ]Ca3 (PO4)2 [Tricalcium phosphate]Ca5 (PO4)3 OH [Hydroxyapatite]Ca5 (PO4)3 F [Fluorapatite]

Phosphate Minerals

5 m

m

1 m

m

6/22/2008 WBL 306/22/2008 WBL 30

VivianiteVivianiteApatiteApatite

W. G. Harris, 2002

16

Phosphate AvailabilityReadily available phosphates

Soil porewaterSoil porewater.

Slowly available phosphatesFe, Al, and Mn phosphates (acid soils) and Ca and Mg

phosphates (alkaline soils) that have been freshly precipitated or are held mostly on the surface of fine particles in the soil. Labile organic compounds.

V l l il bl h h t

6/22/2008 WBL 316/22/2008 WBL 31

Very slowly available phosphatesPrecipitates of Fe, Al, Mn, Ca, and Mg phosphates that

have aged and are well crystallized. Phosphates that were held on particle surfaces have penetrated the particles, little remaining on the surface. Stable organic compounds

PhosphorusIs P one of the redox elements ?Is P one of the redox elements ?

HPO42- + 10H+ + 8e- = PH3 + 4H2O

Is P solubility affected by changes in redox potential?

FePO4 + H+ + e- = Fe2+ + HPO42-

6/22/2008 WBL 326/22/2008 WBL 32

17

Phosphorus RetentionPhosphorus Retentionby Soilsby Soils

Adsorption DesorptionAdsorption –DesorptionPrecipitation – DissolutionImmobilization - mineralization

Retention = Adsorption + Precipitation

6/22/2008 WBL 336/22/2008 WBL 33

Retention = Adsorption + Precipitation+ Immobilization

Sorption of PhosphateIntensity factorIntensity factor : Concentration of h h t i il tphosphate in soil porewater.

Capacity factorCapacity factor : Ability of solid phases to replenish phosphate as it is depleted from solution.

6/22/2008 WBL 346/22/2008 WBL 34

PsolutionPadsorbed

Solidphase

18

Inorganic Phosphate Reactions

Precipitation by Al, Fe, Mn, Ca, and Mg ionsAl3+ + H2PO4

- + 2H2O = 2H+ + Al (OH)2 H2PO4 (insoluble) (Variscite)

Anion exchange

Reaction with hydrous oxidesAl OH2

+ OH + H2PO4- = Al OH2

+ H2PO4 + OH-

OHOH

+ H PO - = AlOHOH + OH-Al

6/22/2008 WBL 356/22/2008 WBL 35

Fixation by silicate claysAl2 SiO5 (OH)4 + 2H2PO4

- = 2Al (OH)2 H2PO4 + Si2O52-

OHOH

+ H2PO4 = AlH2PO4

OH + OHAl

pH- Dependent Charge on Solid Phase

0

[+]

[-]

Cha

rge

Negative charge[loss of H+]

Positive chargeZPC

[ i t h ]

6/22/2008 WBL 366/22/2008 WBL 36

[ ]

3 4 5 6 7 8 9 10pH

Positive charge[gains H+]

[zero point charge]

19

No chargeSolid phase

SoilSolution

Negative chargeSolid phase

Variable Charge on Solid Phase

Al – OH + OH- = Al–O- + H2O

COOH + OH- = COO- + H2O

AlOH + H+ = AlOH2+

6/22/2008 WBL 376/22/2008 WBL 37

AlO- + H+ AlOH + H+ AlOH2+

Negative charge[high pH]

No charge[Intermediate pH]

Positive charge[low pH]

Inorganic Phosphate ReactionsInorganic Phosphate Reactions

Alkaline pH conditions:Alkaline pH conditions:Ca2+ + 2H2PO4

- = Ca (H2PO4)2

Ca (H2PO4)2 + Ca2+ + 2OH- = 2CaHPO4 + 2H2O2CaHPO4 + Ca2+ + 2OH- = 2Ca3 (PO4)2 + 2H2O

6/22/2008 WBL 386/22/2008 WBL 38

20

I: Initial equilibriumcondition

Solid phase Solution phaseI

Sorption of Phosphate

condition

II: Increase in solutionP concentration ---Rapid adsorption tosolid surface

= Phosphate ions

II

6/22/2008 WBL 396/22/2008 WBL 39

III: Diffusion intosolid phase

[Time = seconds to minutes]

[Time = hours to days]

III

ptio

n Smax

Phosphorus Sorption Isotherm

EPCo

Ads

orp

orpt

ion

slope = KDPw

PsPad Pret

Soil

Water

6/22/2008 WBL 406/22/2008 WBL 40

Phosphorus in Soil Porewater

P desorption underambient conditionsD

eso

SoSoil

21


tion

Low P Load

EPCo

Ads

orpt

orpt

ion

EPCoHigh P Load

P Retention

6/22/2008 WBL 416/22/2008 WBL 41


Des

o P Release

Influence of Phosphorus Loading on EPC0

[Nair et al. 1997][Nair et al. 1997]

Land use Total P (mg/kg) EPCo (mg/L)

Intensive 2,330 5.0HoldingPasture 31

181 1.40.1

6/22/2008 WBL 426/22/2008 WBL 42

Beef 31Forage 23 0.2Native

0.1

0.118

22

2

Anaerobic 0-10 cm

Influence of Phosphorus Loading on EPC0

[Everglades – WCA-2a]

0.5

1

1.5

EPC

o (m

g P/

L)

Anaerobic 0-10 cm

Aerobic 0-10 cm

6/22/2008 WBL 436/22/2008 WBL 43

0 2 4 6 8 10 120

Distance from inflow (km)

3000

2400g

Swamp forestMineral/peat soil

[Richardson, 1985]Phosphorus Sorption

2400

1800

1200

P so

rbed

, mg/

kg

Houghton fenPeat soil

Pocosin bogMineral/peat soil

6/22/2008 WBL 446/22/2008 WBL 44

600

00 30 90 150 210

P in solution, mg/L

Pocosin bogPeat soil

23

P Sorption by WCA-2A soils

1,000

1,500

2,000

/kg) DesorptionSite 1

[Anaerobic]

Ambient PW-P

0.01 0.1 1 10 1000

500

Site 8

1 000

1,500

rbed

P (m

g P

Sorption

[Anaerobic]

[Anaerobic]Ambient PW-P

6/22/2008 WBL 456/22/2008 WBL 45

0.001 0.01 0.1 1 10 1000

500

1,000

Solution P concentration (mg P/L)

Sor

SorptionDesorption

Phosphorus Sorption IsothermLinear Equation

S K CS = KL Cwhere: S = mass of P sorbed per mass of solid phase;

C = P concentration in solution; KL = adsorption coefficient related to binding strength

Freundlich EquationS = KF CN [log S = N log C + log KF]where: S = mass of P sorbed per mass of solid phase;

6/22/2008 WBL 466/22/2008 WBL 46

where: S = mass of P sorbed per mass of solid phase; C = P concentration in solution; KF = adsorption coefficient related to binding strength; N = empirical constant

24


Langmuir Equation Slope = 1/SLangmuir EquationS = [k C Smax]/1 + k CC/S = [1/Smax] C + 1/k Smaxwhere: S = mass of P sorbed per mass

of solid phase; C = P concentration in solution; k = constant related to

(C/S

)

C

1/kSmax

Slope = 1/Smax

6/22/2008 WBL 476/22/2008 WBL 47

binding strength; Smax = maximum amount of P sorbed per mass of solid phase

C

ion Adsorption


EPCo

Ads

orpt

ptio

n

Smax

slope = KD

Precipitation

6/22/2008 WBL 486/22/2008 WBL 48


P desorption underambient conditionsD

esor

So

25

Saturation Index (SI)Ca Ab = aC + bA

[C]a [A]b

[Ca Ab]K =

Ion Activity Product (IAP) =Ion Activity Product (IAP) = [C][C]a a [A][A]bb

Sat ration Inde (SI) IAP/KSat ration Inde (SI) IAP/K

6/22/2008 WBL 496/22/2008 WBL 49

Saturation Index (SI) = IAP/KSaturation Index (SI) = IAP/KSI < 1 = Solution is “undersaturated”SI > 1 = Solution is “supersaturated”SI = 1 = Solution saturated (near equilibrium)

P in solution; t = 0r

Precipitation of Phosphate

1

AB

P in solution; t 0

Supersaturation withrespect to B

Supersaturation withrespect to Cen

sity

Fac

tor 1

2

3

6/22/2008 WBL 506/22/2008 WBL 50

C

Capacity Factor

Inte

26

Co-precipitation of Phosphorus

Coating of hydrated ferric oxide(Fe2O3 nH2O) co-precipitatedwith ferric phosphate, aluminum phosphate, and calcium phosphate

6/22/2008 WBL 516/22/2008 WBL 51

Silt or Clay Particle

Pmaxon

Phosphorus Retention Isotherm

Overlying Water

EPCw

P release under

Pmax

slope = AP re

tent

ioea

se

Overlying Water

Rel

ease

Retention

6/22/2008 WBL 526/22/2008 WBL 52

P release underambient conditions

Phosphorus in Water Column

P re

leSediment/Soil

27

High0

Phosphorus Retention Isotherm

P added to water column – range of concentrations

EPCw

6/22/2008 WBL 536/22/2008 WBL 53

Phosphorus Retention byWetlands Soils and Stream

Sediments[Okeechobee Basin Florida]

WetlandsPr = 118 [SRP] - 54.2 r2 = 0.71 n = 11EPCw = 0.47 mg P/L

Stream sediments

[Okeechobee Basin, Florida]

6/22/2008 WBL 546/22/2008 WBL 54

Stream sedimentsPr = 128 [SRP] - 12.4 r2 = 0.95 n = 175EPCw = 0.1 mg P/L

28

20

40ea

se

EPCw=33 ug/L

Phosphorus Retention byMud Sediments – Lake Okeechobee

-80

-60

-40

-20

00 20 40 60 80 100 120 140

P re

tent

ion/

rele

(mg/

m2

Year

)

P re

leas

e y

sedi

men

ts

P retention by sediments

6/22/2008 WBL 556/22/2008 WBL 55

-120

-100

DR

P

Water Column DRP ug/L

by

1,2002

Phosphorus Adsorption Coefficient[Organic Soils]

K [

L/kg

]

400

600

800

1,000 r2 = 0.89n = 36

6/22/2008 WBL 566/22/2008 WBL 56

0 20 40 60 800

200

Ash content (%)

29

50kg

)

Phosphorus Retention CapacityPhosphorus Retention CapacityMineral Wetland Soils Mineral Wetland Soils -- Okeechobee

Basin

10

20

30

40

ax (m

mol

es P

/k Smax = 1.74 + 0.172 [Fe + Al]r2 = 0.78 n = 285

0.1 0.3 1 3 10 30 100 3000Sm

a

Oxalate Extractable [Fe + Al] (mmol/kg)

200

160 Y = 1 21+0 015(x)

Phosphorus Retention Phosphorus Retention ––Peat/Mineral Wetland Soils Peat/Mineral Wetland Soils

160

120

80

sorb

ed [m

g/kg

]/og

of P

in s

olut

ion Y = 1.21+0.015(x)

R2 = 0.87

6/22/2008 WBL 586/22/2008 WBL 58

40

0 0 2 4 6 8 10

P lo

Oxalate extractable Al, g/kg

Richardson, 1985

30

Phosphorus solubility as a function of pH and Eh

6/22/2008 WBL 596/22/2008 WBL 59

Iron solubility as a function of pH and Eh

6/22/2008 WBL 606/22/2008 WBL 60

31

P)

Dissolved P in Sediments

Dis

solv

ed P

(uM

6/22/2008 WBL 616/22/2008 WBL 61

Phosphorus Solubility under Anaerobic Soil Conditions

SO42- H2S + FePO4

Fe2+ + PO43- FePO4FeS

Fe(OH)2-PO4

[Strengite]

6/22/2008 WBL 626/22/2008 WBL 62

Fe3(PO4)2[Vivianite]

[Strengite]

32

6000

7000l) OxidizedOxidized

Lake Okeechobee

2000

3000

4000

5000

6000ac

tivity

(cpm

/ml

ReducedReduced

6/22/2008 WBL 636/22/2008 WBL 63

Littoral Peat Mud Mud Mud Mud0

1000

2000

32P

a

Mechanisms of Phosphorus Release in Wetlands

Reduction of insoluble ferric phosphate to more p psoluble ferrous phosphateRelease occluded phosphate by reduction of hydrated ferric oxide coatingHigher solubility of ferric and aluminum phosphates due to increased soil pHDisplacement of phosphate from ferric and aluminum phosphate by organic anions

6/22/2008 WBL 646/22/2008 WBL 64

p p y gIncreased phosphate availability during sulfate reductionIncreased solubility of calcium phosphate in alkaline soils as result of pH decrease under flooded conditions

33

Regulators of Inorganic Phosphorus Retention

pH and EhpH and EhPhosphate concentrationClay contentIron and aluminum oxidesOrganic matter content

6/22/2008 WBL 656/22/2008 WBL 65

Calcium carbonate contentTime of reaction/agingTemperature


Phosphorus Cycle

AEROBIC

Peataccretion


Litterfall

DOP DIP PIPPOP

DIP

DIP


Outflow

Periphyton P

6/22/2008 WBL 666/22/2008 WBL 66

ANAEROBIC

accretionPIP

Ca-bound P]Adsorbe

d IP

DIP

POP DOPDOP

DIP

34

Plant LitterAttached POP DOP Epiphytic

i h tEALeaching

Organic Phosphorus

Attached to plant

Detritusdeposited

on soil surface

Decomposeddetritus from pervious years

POP periphyton

POP DOP DIP Benthic periphyton

Microbialbiomass

POP DOP DIPInorganicsolids

Microbial

EA EA

EA EA

6/22/2008 WBL 676/22/2008 WBL 67

Well decomposeddetritus accreted

into soil

Microbialbiomass

POP DOP DIPInorganicsolids

EA EA

Detrital Matter

Organic Phosphorus

PhytinPhospholipidsNucleic acids

Sugar phosphatesPlantsAnimalsMicrobes

Humus

6/22/2008 WBL 686/22/2008 WBL 68

Inorganic Phosphate

Microbes

35

Organic P fractions (% of total organic P) in growing organisms and soils*

>5025102220Monoesters

523302015Phospholipids

252605865Nucleic Acids

SoilsNicotianaSpirodellaFungiE. coli

6/22/2008 WBL 696/22/2008 WBL 69

*From Magid, et al., (1996) after numerous sources.

Soil Phosphorus

TPo = -49 + 0.89 TP1,000

Blue Cypress Marsh

600

800

TPo

(mg

kg-1

)

NENW

6/22/2008 WBL 706/22/2008 WBL 70

400

T

400 600 800 1000TP (mg kg-1)

NWSW

36

Organic PhosphorusOrganic Phosphorus

Microbial biomass P y Hi hMicrobial biomass PLabile organic PFulvic acid - PHumic acid - PResidual organic P

Bio

avai

labi

lity High

Low

6/22/2008 WBL 716/22/2008 WBL 71

Residual organic P

Soil phosphorus compositionSoil phosphorus composition

O th h h t tO th h h t t

Solution 31P NMR spectrum of an alkaline extract of a Swedish tundra soil

Solution 31P NMR spectrum of an alkaline extract of a Swedish tundra soil

PhosphonatesPhosphonates

Inorganic orthophosphate

Inorganic orthophosphate

PhospholipidsPhospholipids

Orthophosphate monoestersOrthophosphate monoesters

Polyphosphate end-groupsPolyphosphate end-groups

Mid-chain l h h

Mid-chain l h h

DNADNA

P h hP h h

6/22/2008 WBL 726/22/2008 WBL 72

pppolyphosphatespolyphosphatesPyrophosphatePyrophosphate

Chemical shift (ppm)Chemical shift (ppm)-20-20-10-100010102020

37

OxygenReduction

ExtracellularEnzymaticActivity

Organic Matter Decomposition and Nutrient Release

Simple

Compounds

ComplexOrganic

OrganicMatter

Hydrolysis

OrganicCompounds

Acid Fermentation

ManganeseReduction

Iron Reduction

NitrateReduction

Sulfate

BioavailableNutrients

Activity

CO2

6/22/2008 WBL 736/22/2008 WBL 73

Short-chainFatty Acids CO

Reduction

SulfateReduction

2

BioavailableNutrients

CH4Hydrogen

Periphyton/Macrophytes

Phosphorus Availability

Detrital MatterPh i

Organic P + P+Organic

PhytinPhospholipidsNucleic acids

Sugar phosphates

6/22/2008 WBL 746/22/2008 WBL 74

EnzymesPhosphatases

38

S +S + EE EE SS EE PP

Enzyme – Catalyzed Reaction

S + S + EE E E SS EE + P+ P

S = Substrate E = Enzyme P = Product

R - O-PO32- + H2O R-OH + HO-PO32-

6/22/2008 WBL 756/22/2008 WBL 75

R O PO3 H2O R OH HO PO3

Alkaline phosphataseEsterlinkage

Phosphatase ActivityPeriphyton APA along the WCA 2a

Nutrient GradientJuly 1996 [Newman, S]

200

300

400

500

6/22/2008 WBL 766/22/2008 WBL 76Source: Newman, unpubl’d data

0

100

0 2 4 6 8 10 12 14 16Distance from the S10s (km)

39

Periphyton

6/22/2008 WBL 776/22/2008 WBL 77

Phosphatase-Cyanobacterial Cells

PPB

C

6/22/2008 WBL 786/22/2008 WBL 78

40

20

25May 1996l )

Alkaline Phosphatase ActivityEverglades- WCA-2A

5

10

15

20

p-ni

troph

enol

(mg

g-1hr

-1) Litter

0-10 cm10-30 cm

6/22/2008 WBL 796/22/2008 WBL 79

00 1 2 3 4 5 6 7 8 9 10 11


our

Soil Phosphatase Activity

400 NE

Blue Cypress Marsh

PA, m

g M

UF/

g h

o

100

200

300NW [R]

SW

6/22/2008 WBL 806/22/2008 WBL 80

Mar June July Sept Dec Jan

2001 2002

AP

0

41

Phosphatase Activity[Sunnyhill Farm Wetland]

gg--1 1 hh--11 400

Acid Phosphatase

pp--ni

trop

heno

l g

nitr

ophe

nol

g

100

200

300Acid PhosphataseAlkaline PhosphataseTotal Phosphatase

6/22/2008 WBL 816/22/2008 WBL 81

μμg g pp

Oxygen Nitrate Sulfate BicarbonateEh (mV) 616 228 -162 -217pH 4.7 7.5 7.7 6.6

0

y = 0.36x - 0.32R2 = 0.72100

120140

izat

ion

h-1

Sunnyhill Farm Wetland

020406080

100

anic

P M

iner

alm

g P

g-1 dw

6/22/2008 WBL 826/22/2008 WBL 82

00 100 200 300

Total Phosphatase Activitymg p-nitrophenol g-1 h-1

Org

42

30

Microbial Biomass P[Sunnyhill Farm Wetland][Sunnyhill Farm Wetland]

10

20

Mic

robi

al P

,M

icro

bial

P,

(% o

f tot

al P

)(%

of t

otal

P)

6/22/2008 WBL 836/22/2008 WBL 83

0Oxygen Nitrate Sulfate icarbonate

Eh (mV) 616 228 -162 -217pH 4.7 7.5 7.7 6.6

25Feb'96 Aug.'96 Mar. '97

P

Microbial Biomass Phosphorus[Water Conservation Area[Water Conservation Area--2A]2A]

510

15

20 0-10 cm Soil Depth

robi

al b

iom

ass

(as %

tot

al P

)

05

0 2 4 6 8 10Distance from inflow (km)

Mic (

43

6070

m-2

1.5

Lake Apopka Marsh

1020304050

uble

reac

tive

P, m

g m

0.5

1SO4 -S

NO3 -N

O

g m

-2

6/22/2008 WBL 856/22/2008 WBL 85

4 60

10

Time, daysSo

lu0

02 4 6

Time, days

O2

0 2

Soluble P, mg L-1

1 2Dissolved Fe, mg L-1

3

Lake Apopka Marsh

Water

epth

, cm

0102030

2 4 6 8 1 20 0 3

6/22/2008 WBL 866/22/2008 WBL 86

De 0

-20-10 Soil

44

BP = Benthic PeriphytonFP = Floating PeriphytonEP = Epiphytic Periphyton

Periphyton-Phosphorus-Interactions

Soluble PEPFP

BP

Ca Ca -P

EP Epiphytic Periphyton

Water

6/22/2008 WBL 876/22/2008 WBL 87

BP

Soluble PSoil

Calcareous Periphyton Mats

6/22/2008 WBL 886/22/2008 WBL 88

45

Calcareous Periphyton Mats

6/22/2008 WBL 896/22/2008 WBL 89

With CaCOWith CaCO33 Without CaCOWithout CaCO33

6/22/2008 WBL 90

46

6/22/2008 WBL 91

Distribution of 32P between Water and Benthic Periphyton

1010 2211

WaterWater

Abi tiAbi ti

Light = 10 W mLight = 10 W m--22

22%22%

5%5%

10%10%

2%2%

Water DRP = 5 ug LWater DRP = 5 ug L--11

PeriphytonPeriphyton

6/22/2008 WBL 926/22/2008 WBL 92

AbioticAbiotic

BioticBiotic

1 hour1 hour 12 hour12 hour

74%74%22%22%

88%88%

47

P

Periphyton-Phosphorus-CaCO3 Interactions

P

P

P

PPeriphyton

6/22/2008 WBL 936/22/2008 WBL 93

PSolution P CaCO3

3000

) Live-above ground

Plant Tissue PhosphorusPlant Tissue Phosphorus--WCAWCA--2A2A

500

1000

1500

2000

2500

Tota

l P (m

g kg

-1 Detritus-above groundBelow ground

6/22/2008 WBL 946/22/2008 WBL 94

0

500

F-1 Typha

F-3 Typha

F-3 Cladium

F-5 Cladium

T

Impacted Transition Unimpacted

48

1

1.2

tion

Everglades-WCA 2AR2 = 0.969

0.2

0.4

0.6

0.81

phor

us A

ccum

ulat

(g/m

2ye

ar)

6/22/2008 WBL 956/22/2008 WBL 95

0 5 10 15 20 25 30 350

0.2

Calcium Accumulation (g/m 2 year)

Phos

p

DIP DOP

Soil/Sediment-Water Interactions

DIP DOP PIP POP

SedimentationResuspensionDiffusionWater

Soil/Sediment

DIP DOPPorewater

PIP POP

49

Total Phosphorus in WCA-2A soils (0-10 cm)

1990 1998

6/22/2008 WBL 976/22/2008 WBL 97DeBusk et al. 2001

External LoadReduction

horu

s

Phosphorus Memory

Internal Memory

BackgroundLevel

r Col

umn

Pho

sph

6/22/2008 WBL 986/22/2008 WBL 98

Lag time for Recovery

Wat

er

Time - Years

50

Water Column

Internal Phosphorus Load

Soil

6/22/2008 WBL 996/22/2008 WBL 99

ExternalNutrient Periphyton

Nutrient Impacts in Wetlands

Load

InternalNutrient

Load

Vegetation

Detritus

Water

6/22/2008 WBL 1006/22/2008 WBL 100

Microbial/ChemicalProcesses

Load0-10 cm

10-30 cm

51

Soluble Phosphorus Flux from Sediments

6/22/2008 WBL 1016/22/2008 WBL 101

Lower St. Johns River- SRP ProfilesBeauclair

BluffDoctors

LakeColleeCove

RacyPoint

-20

-15

-20

-15

-20

-15

-20-15

-20

-15

-20

-15

-20

-15

[Malecki et al. 2003]

Dep

th (c

m)

-10

5

10

15

20

25

30

15

-10

-5

5

10

15

20

25

-15

-10

-5

05

10

15

20

25

15-10-50

-15

-10

-5

051015202530

5

10

15

20

25

15

-10

-5

5

10

15

20

25

-15

-10

-5

0

5

10

15

20

25

6/22/2008 WBL 1026/22/2008 WBL 102

2.64 ± 0.85 mg m-2 d-1

7.38 ± 1.71 mg m-2 d-1

1.26 ± 0.29 mg m-2 d-1

4.09 ± 0.03 mg m-2 d-1

SRP conc. (mg L-1)

35

4045

SRP concentration (mg L -1)

25

30

35

SRP concentration (mg L -1) SRP concentration (mg L -1)

30

350 4 8 12

SRP conc. (mg L-1) SRP conc. (mg L-1) SRP conc. (mg L-1)0 4 8 12 0 4 8 12 0 4 8 12

35 25

30

35

25

30

35

25

30

35

52

Internal vs. External Loads

44%32%

TN Lower St. Johns River Estuary

24%

Total Non-pointTotal Point SourceTotal Internal Load

42%25%TP

Total = 7,969 mt year-1

6/22/2008 WBL 103

33%

Total Non-point Total Point SourceTotal Internal Load

[J. R. white 2004]Total = 1,600 mt year-1

Phosphorus Flux from Soil to Water ColumnStation Porewater Benthic IncubatedStation Porewater

equilibratorsBenthicchambers

IncubatedSoil cores

[km]

1.4 0.3 10.0 6.5

[mg P/m2 day]

6/22/2008 WBL 1046/22/2008 WBL 104

3.3 0.8 9.1 1.5

10.1 -0.001 ND ND

53

Flooded Agricultural Land Lake Griffin Flow-way, Florida

Station P – Flux EPCw

mg P m-2 day-1

DRP TP

w

mg L-1

1D 0.40 0.74 0.11

2E 0.94 1.54 0.25

6/22/2008 WBL 105

3D 1.62 2.38 0.43

5C 0.25 0.34 0.07

P memory = 30 – 140 yearsReddy et al., 1997

Internal Phosphorus Load Everglades -WCA-2A

6

y)

12345

P flu

x (m

g P

/m2

day

6/22/2008 WBL 1066/22/2008 WBL 106

00 2 4 6 8 10 12


(

54

6

Phosphorus Flux from FloodedAgricultural Land

y = 5.31 e-0.051x

R2 = 0.95

12345

P flu

x m

g P

/m2

day)

6/22/2008 WBL 1076/22/2008 WBL 107

00 10 20 30 40

Time after flooding (months)

(m

Soluble Phosphorus Flux from Wetlands

mg/m2 day

Lake Apopka Marsh 2- 5.50.3 - 1.1Disney World

Orange County 0.02 – 0.16STA-1W 0.3- 1.6

6/22/2008 WBL 1086/22/2008 WBL 108

55

Soluble Phosphorus Flux from Sediments [mg P/m2 day]

Lake Apopka 1 - 5.3Lake OkeechobeeLake Okeechobee

0.1 - 1.9Mud ZonePeat Zone 0.2 - 2.2Sand ZoneLittoral Zone

0.1 - 0.50.6 - 1.5

Lower St Johns River 1 3 7 4

6/22/2008 WBL 1096/22/2008 WBL 109

Lake Barco 0.02 - 0.05

Otter Creek -0.8 - 3.3Indian River Lagoon 0.6 - 1.7

Lower St. Johns River

Tampa Bay 1.9 - 6.3

1.3 - 7.4

Soluble Phosphorus Flux from Sediments

PPPP

PPPPDRPDRP

DRPDRP

Water columnWater column

6/22/2008 WBL 1106/22/2008 WBL 110

SedimentSediment

56

0 1

0.15CaCO3 Ca(OH)2od

wat

er

Lake Apopka Marsh SoilsLake Apopka Marsh Soils[Effect of Chemical Amendments on Phosphorus Release]

0

0.05

0.1

0.1

0.15 Dolomite CaCO3 + Ca(OH)2

le P

rele

ased

into

floo

(mm

ol P

/kg)

4 3 + 3 2 t/h

8.6 t/ha 6.3 t/ha

6/22/2008 WBL 1116/22/2008 WBL 111

0 200 400 600 800 1,000

0

0.05

0 200 400 600 800 1,000

Solu

b

Ca2+ added (mmol/kg)

4.3 + 3.2 t/ha8.2 t/ha

Alum0.1

0.15FeCl3

oodw

ater

(a) (b)

Lake Apopka Marsh SoilsLake Apopka Marsh Soils[Effect of Chemical Amendments on Phosphorus Release]

4 50

0.05

Alum + CaCO3

0.05

0.1

0.15

ble

P re

leas

ed in

to fl

o(m

mol

P/k

g)

(c) (d)FeCl3 + CaCO3

4.0 t/ha1.0 t/ha

2.1 + 4.3 t/ha0.5 + 2.5 t/ha

6/22/2008 WBL 1126/22/2008 WBL 112

0 10 20 30 400 10 20 30 40

0

Fe3+ added (mmol/kg)

Solu

b

Al3+ added (mmol/kg)

57

FePO4 Fe3+ + PO43- Organic P

O2 PO43- Periphyton/Detritus

Water Columnprecipitation

Processes Controlling Phosphorus Processes Controlling Phosphorus

diffusion

4 4 g

Fe2+ PO43-

Fe2+ + PO43-

3 Fe2+ + 2 PO43- Fe3(PO4)2

FePO4 Organic P(amorphous)

(amorphous)

Aerobic

Soi

l/Sed

imen

t

oxidation

burial burial

reduction

diffusion

diffusion

6/22/2008 WBL 1136/22/2008 WBL 113

Fe2+ + CO32- FeCO3

3Ca2+ + 2PO43- B-Ca3(PO4)2

Ca2+ + CO32- CaCO3

(beta tricalcium phosphate))

(calcite))

(siderite)

(vivianite)Anaerobic precipitation


Phosphorus Cycle

AEROBIC

Peataccretion


Litterfall

DOP DIP PIPPOP

DIP

DIP


Outflow

Periphyton P

6/22/2008 WBL 1146/22/2008 WBL 114

ANAEROBIC

accretionPIP

Ca-bound P]Adsorbe

d IP

DIP

POP DOPDOP

DIP

58

Summary


Common inorganic phosphorus pools include: loosely bound; fractions associated with Al, Fe, and Mn oxides and hydroxides; Ca and Mg bound fraction; mineralsPhosphate is not commonly used as an oxidant, but is affected by redox dynamics. Oxidized forms of iron can react with phosphorus and form insoluble compoundsSoil’s capacity to adsorb phosphorus is regulated by the EPCo, at which point adsorption equals desorptionI i h h t ti i l t d b H Eh h h t

6/22/2008 WBL 1156/22/2008 115

Inorganic phosphorus retention is regulated by pH, Eh, phosphate concentration (there is a limited amount of substrate for adsorption), concentrations of Fe, Al, and calcium carbonate, and temperature

Summary


Much of the organic phosphorus is present as monoesters and diesters. Monoesters include sugar phosphates, phosphoproteins, mononucleotides, and inositol phosphates. Diestersinclude nucleic acids, phospholipids, and aromatic compounds. Compared to monoesters, diesters are more accessible to microbial attack. Organic phosphorus availability from monoesters requires enzymatic cleavage of the ester linkage. This occurs primarily through several extracellular enzymes such as phosphatases

6/22/2008 WBL 1166/22/2008 116

g y p pthrough hydrolysis of phosphate esters. The “phosphorus memory” can extend the time required for a wetland or an aquatic system to reach an alternate stable condition to meet environmental regulation such as TMDLs (total daily maximum daily load

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Transcript of Institute Food Agricultural Sciences (IFAS ......6/22/2008 WBL 9 [50%] 1996 Florida 2003 North...