Ammonia volatilisation from livestock slurries and mineral fertilizers

Sven G. Sommer Technical Faculty, University of

Southern Denmark

Nitrogen, Phosphorus and Oxygen NPO-decade (Overgård 1982; Sommer 1982)

• NPO was the front runner of the Action Plan for the Aquatic

• Environment I to III (APAE-I-III, Vandmiljøhandlingsplaner).

Nanimal manure, kg N Ha-1

0 20 40 60 80 100 120

Nap

plie

d -

Nne

ed,

Kg

N H

a-1

0

10

20

30

40

50

60

Nitrat i brøndvand

År1930 1940 1950 1960 1970 1980 1990

3

2

4

6

8

10

12

14

Year

Nitrate in well water

Nitr

ate,

NO

3 pe

r ltr.

• Nitrate bomb • Blue babies

Ammonium in rainwater (Sommer, 1984 & 2013). Idea for this work was provided by Eivind Hansen, Head of

Centre for Terrestrial Ecology • Acidification and eutrophication

of natural ecosystems

• Airborne particulates that is a health hazard

• UN have included NH3 in the Convention on Long-range Transboundary Air Pollution (CLRTP)

• EU has set a limit – the NH3 ceiling – to the emission of NH3

Year

1920 1930 1940 1950 1960 1970 1980

Dep

ositi

on o

f N

, kg

N h

a-1

0

2

4

6

8

10

12AmmoniumNitrate

Example of EU regulations the Gothenborg protocol deals with ammonia

Reduced NH3 emission from 1990 to 2010, in pct. of emission in 1990

0 20 40 60 80

Reduction targets

Netherland

Belgium

Portugal

United Kingdom

Germany

Sweden

Austria

Reduced NH3 emission from 1990 to 2010, in pct. of emission in 1990

0 10 20 30 40 50 60 70

ReductionReduction target

Netherland

Belgium

Portugal

United Kingdom

Germany

Sweden

Austria

Ammonia emission - processes

From: • Stored slurry • Slurry applied in the field • Mineral fertilizer in the field

They have the release and emission processes in common

(Temp)/KO)(H1TAN(aq)(aq)NH

N33 ++

=(aq)][NH(aq)][NH[TAN] 34 += +

Understanding the system, slurry applied onto soil

Hours

0 48 96 144 192

Cum

ulat

ed N

H3-

emis

sion

, % o

f TA

N

0

5

10

15

20

Emis

sio

n r

ate,

kg

NH

3-N

h-1

0.0

0.5

1.0

1.5

2.0

2.5

Slurry applied onto soil (Sherlock, Sommer, Khan, Wood, Guertal, Freney, Dawson and Cameron, 2002; Sommer,

Olesen and Christensen, 1991)

Hours

0 48 96 144 192C

umul

ated

NH

3-em

issi

on, %

of T

AN

0

5

10

15

20

Emis

sio

n r

ate,

kg

NH

3-N

h-1

0.0

0.5

1.0

1.5

2.0

2.5

Hours from or applying slurry

0 50 100 150 200 250 300

Sur

face

pH

7.4

7.6

7.8

8.0

8.2

8.4

8.6

8.8 Sherlock et al. (2002)Sommer et al. (1991)

The pH buffer system of animal slurry and anaerobic digested slurry (Sommer and Husted, 1995)

HCO3−(aq) + H3O+(aq) ⇌ CO2 aq + 2H2O l

R − COOH(aq) + H2O(l) ⇋ RCOO−(aq) + H3O+(aq)

NH4+(aq) + H2O l ⇌ NH3 aq + H3O+(aq)

Pig slurry

pH

0 2 4 6 8 10 12 14

Buf

ferc

apac

ity,

(meq

L-1

) pH

-1

0

20

40

60

80

100

120

140 Measured Predicted

Electric charge of organic matter - particles (Sommer and Husted, 1995)

TAL: Total Alkalinity is the amount of equivalents of hydrons (H+(aq)) that has to be added to the biomass to reduce pH to 4.5.

Dry matter, g kg-1

0 20 40 60 80 100 120

Res

idua

l alk

alin

ity,

eq.

mol

L-1

0.00

0.05

0.10

0.15

0.20

The negative charged particles may explain the low emissions after 24-48 h – i.e. only 15-20% of the TAN is lost.

Hours

0 48 96 144 192

Cum

ulat

ed N

H3-

emis

sion

, % o

f TA

N

0

5

10

15

20

Emis

sio

n r

ate,

kg

NH

3-N

h-1

0.0

0.5

1.0

1.5

2.0

2.5

Organic matter (Dry matter) in slurry may also reduce infiltration of slurry liquid containing TAN

(Sommer and Olesen, 1991)

Dry matter content, g L-1

0 50 100 150 200 250

Emis

sion

, %

of

TAN

0

20

40

60

80

100

1206 hours6 days6 hours6 days

Dry matter (DM) is an indicator of reduced liquid infiltration

(Thygesen, Triolo and Sommer, 2012)

• High viscosity • Seal soil surface • Increase water

retention

Dry matter, %

0 2 4 6 8 10

Vis

cosi

ty,

cP

F(x)=1.82·e0.606·x

R2=0.83

1000

100

10

1

NH3 volatiliasation vs. infiltration (Sommer and Jacobsen, 1999)

Bromide infiltration

Bromide, mg Br- kg-1(dry soil)

0 50 100 150 2001000 2000

Dep

th,

cm

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0.01 g(H2O) g-1(soil)

0.12 g(H2O) g-1(soil)

0.19 g(H2O) g-1(soil)

TAN (NH3+NH4+) infiltration

TAN, mg TAN- kg-1(dry soil)

0 200 400 600 800D

epth

, cm

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0.01 g(H2O) g-1(soil)

0.12 g(H2O) g-1(soil)

0.19 g(H2O) g-1(soil)

NH3 volatilisation

Time from start of experiment, h0 12 24 36 48 60 72 84 96

NH3,

NH 3

% o

f TAN

0

10

20

30

40

0.01 g(H2O) g-1(soil)

0.12 g(H2O) g-1(soil)

0.19 g(H2O) g-1(soil)

Empirical emission model (Sherlock, Freney, Bacon and van der Weerden, 1995; Sommer, Søgaard, Møller and Morsing,

2001)

)NHNH( A3,G3, −××= uKF

• Wind (u) speed at 1 m above source

• K dependent on surface characteristic (Here bare soil)

• Air temperature • TAN and pH in source

surface

[ ] [ ][ ] N3

G3, /KOH1TAN(aq)1NH

++⋅=

H

u x [NH3(g)] mg(N) m-2 s-1

0 50 100 150 200 250 300 350Emis

sion

mea

sure

d, m

g(N

) m

-2 s

-1

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

Sherlock et al. 1995Sommer et al. 2001

Atmospheric transfer model (Olesen and Sommer, 1993)

FA =1

Ra + Rb + Rc∙ ( NH3,𝐺𝐺 − NH3,a )

Ra Turbulent air resistance

Rb Laminar air layer resistance

Rc Surface layer resistance

𝑅𝑅𝑎𝑎 x, t =ln( 𝑙𝑙z0

)

κ · u∗(t) z0: roughness length of the surface 𝑙𝑙: height of the internal boundary layer

𝑈𝑈∗: friction velocity 𝑅𝑅𝑏𝑏 = 6.2 ∙ u∗−0.67

Rc : measured resistance

Atmospheric emission model (Olesen and Sommer, 1993)

Ra=18 s m-1; at 8 m s-1 Ra=71 s m-1; at 2 m s-1

Rb= 9 s m-1; at 8 m s-1 Rb=22 s m-1; at 2 m s-1

Rc Manure store Uncovered: Rc= 18 s m-1; Surface crust: Rc=118 s m-1

Rc Fertilizer or manure in field Bare soil vs. high plants: Rc= 10 - 230 s m-1

Rc= 10 - 230 s m-1;

Micrometeorological transfer model slurry store (Sommer, Sibbesen, Nielsen, Schjørring and Olesen, 1996)

Data Initial bulk TAN and pH Hourly climate data, air

temperature and wind speed

Diffusion/convection transport of TAN in slurry

Rc set to =0 Assumed that effect of

distance from slurry surface to rim of the tank may improve model performance? Measured NH3 emission, g N m-2d-1

0 1 2 3 4 5

Estim

ated

NH

3 em

issi

on,

g N

m-2

d-1

0

1

2

3

4

5

1:1 line

Trail hose application of slurry (Thorman, Hansen, Misselbrook and Sommer, 2008)

Crop height (cm)0 20 40 60 80Em

issi

on re

lativ

e to

unc

ropp

ed, p

ct

0

20

40

60

80

100

120 F(x)=-1,1+91,4x, r2=0.73

Effect of increasing infiltration – harrowing the soil before slurry application

(Sommer and Ersbøll, 1994)

Hours from start of experiment

0 24 48 72 96 120 144

NH

3 em

issi

on,

% o

f TA

N

0

10

20

30

40

50 Harrowed soilUnworked soil

Direct injection of slurry applied in field (Hansen, Sommer and Madsen, 2003)

Volume of slot, m3 ha-1

0 10 20 30 40 50 60 70

Emis

sion

rela

tive

to tr

ail h

ose

appl

ied,

%

102030405060708090

Acidification of slurry (Kai, Pedersen, Jensen, Hansen and Sommer, 2008)

Nitrogen loss, % of total N

0 10 20 30 40 50

UntreatedAcidified

Winter 6 mth.

Whole year 12 mth.

Slurry storage Slurry applied in the field

Hours from slurry application

0 50 100 150

NH

3 em

issi

on,

% o

f am

mon

ium

0

10

20

30

40

50

60

AcidifiedUntreated

Factors affecting ammonia loss – The ALFAM model (Søgaard, Sommer, Hutchings, Huijsmans, Bussink and Nicholson, 2002)

Experimental factor Effect on NH3 volatilisation

Soil moisture Wet soil 10% higher than dry soil

Air temperature +2% per °C

Wind speed +4% per m/sec

Slurry type Pig slurry 14% less than cattle slurry

Dry matter content +11% per % DM

TAN content Positive

Manure incorp. No incorp. 11 times higher than shallow cult. and injection

Link: WWW.ALFAM.dk

The ALFAM model – Validation (Søgaard, Sommer, Hutchings, Huijsmans, Bussink and Nicholson,

2002)

Observed NH3 volatilization,pct.

0 10 20 30 40 50 60

Pred

icte

d N

H3 v

olat

iliza

tion,

pct.

0

10

20

30

40

50

60

Trail hoseInjectionr2=0.596

Conclusion

• Efficient techniques to reduce emission are developed and in use

• Models estimating ammonia emission from stored and applied manure should be developed accounting for the environmental condition, manure characteristics, management and treatment

• We need to improve our understanding “source” surface pH Perspective • Animal production is increasing and production systems

changes without adapting manure management. This lead to increased pollution – which has to be reduced by developing environmentally friendly manure management.