ammonia emissions and emission factors: a summary of investigations at beef cattle feedyards on the...
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Ammonia emissions from beef cattle feedyards: Seven years of research in Texas
Richard W. ToddN. Andy Cole
Heidi M. Waldrip
USDA Agricultural Research ServiceConservation and Production Research Laboratory
Bushland, TX
Precursor to respirable particulates
Overfertilization of N-sensitive terrestrialecosystems
Eutrophication of surface waters, toxic algal blooms
Hypoxic bottom zone, Gulf of Mexico
Ammonia Impacts
FeedProduction
FeedProduction
Atmospheric NH3
50
Atmospheric NH3
50
Removed20
>95%of total
volatilizedNH3
Diet100
Excreted N85%
Pens Retentionpond
5
Runoff
Stockpile, compost,land application
Nitrogen flows in the feedyard
< 5%
Bierman et al. (1999), Cole et al. (2006), Farran et al. (2006), Flesch et al. (2007), Todd et al. (2008)
15 10
Haber-BoschProcess
N2
Natural gas
NH4+ fertilizer
Feedyard C (FYC)2002-2005
44,700 head
Feedyard A (FYA)2006-2009
12,700 head
Feedyard E (FYE)2006-2009
19,600 head
50403020 60 70 80
Ammonia-N loss as % of fed N
FG(b)
NP(b)
FG(b)
NP(b)
LD(a)LD
(a)
LD(c)
GD(d)
LD(f)
LD(f)
GD(d)
LD(f)
LD(f)
(a) Harper et al. (2004)(b) Todd et al. (2005)(c) Flesch et al. (2007)(d) Todd et al. (2008)(e) Rhoades et al. (2010)(f) Todd et al. (2011)
CD Chemilum./dispersion modelFG Flux-GradientGD Gas washing/dispersion modelLD Open path laser/dispersion modelNP N:P ratio
CD(e)
CD(e)
Winter
Summer
Inverse dispersion technique to estimate emission(Flesch et al., 2005)
• Ammonia concentration
• Atmospheric turbulence
• Carefully defined source area
FYC
Six seasonal campaigns43 complete days
Todd, R.W., N.A. Cole, R.N. Clark, T.K. Flesch, L.A. Harper, and B.-H. Baek. 2008. Ammonia emissions from a beef cattle feedyard on the southern High Plains. Atmos.Environ. 42:6797-6805.
FYC Per Capita Fed N or NH3-N Loss
Campaign
Su02 W03 Su03 W04 Su04 Sp05
Per
cap
ita N
loss
(g
head
-1 d
-1)
0
50
100
150
200
250fed N NH3-N
Mean Monthly Per Head Ammonia-N Emission Rate
Feb-0
7
Mar
-07
Apr-0
7
May
-07
Jun-
07
Jul-0
7
Aug-0
7
Sep-0
7
Oct-07
Nov-0
7
Dec-0
7
Jan-
08
Feb-0
8
Mar
-08
Apr-0
8
May
-08
Jun-
08
Jul-0
8
Aug-0
8
Sep-0
8
Oct-08
Nov-0
8
Dec-0
8
Jan-
09
Per
cap
ita a
mm
onia
-N e
mis
sion
rat
e (g
hea
d-1 d
-1)
0
50
100
150
200
250
Feedyard EFeedyard A
Mean Monthly Ammonia-N Emission Rate and Crude Protein
Feb-0
7
Mar
-07
Apr-0
7
May
-07
Jun-
07
Jul-0
7
Aug-0
7
Sep-0
7
Oct-07
Nov-0
7
Dec-0
7
Jan-
08
Feb-0
8
Mar
-08
Apr-0
8
May
-08
Jun-
08
Jul-0
8
Aug-0
8
Sep-0
8
Oct-08
Nov-0
8
Dec-0
8
Jan-
09
Per
cap
ita a
mm
onia
-N e
mis
sion
rat
e (g
hea
d-1 d
-1)
0
50
100
150
200
250
Cru
de p
rote
in c
onte
nt (
%)
0
5
10
15
20
25Feedyard E ERFeedyard A ERFeedyard E CPFeedyard A CP
Mean Annual Ammonia-N Loss as Fraction of Fed N
Year Feedyard E Feedyard A
% of fed N
Feb07-Jan08 52 49
Feb08-Jan09 47 66
Todd, R.W., N.A. Cole, M.B. Rhoades, D.B. Parker, and K.D. Casey. 2011. Daily, monthly, seasonal and annual ammonia emissions from southern High Plains cattle feedyards. J. Environ. Qual. 40:1-6.
Mean Annual Ammonia Emission Rates
Feedyard 2002-05 2007 2008
lb NH3 animal-1 d-1
FYC 0.26
FYA 0.24 0.37
FYE 0.22 0.20
Todd, R.W., N.A. Cole, R.N. Clark, T.K. Flesch, L.A. Harper, and B.-H. Baek. 2008. Ammonia emissions from a beef cattle feedyard on the southern High Plains. Atmos.Environ. 42:6797-6805.
Todd, R.W., N.A. Cole, M.B. Rhoades, D.B. Parker, and K.D. Casey. 2011. Daily, monthly, seasonal and annual ammonia emissions from southern High Plains cattle feedyards. J. Environ. Qual. 40:1-6.
Fractional Ammonia Loss% of fed N
Feedyard Summer Winter Annual
% of fed N
FYC 68 36 53
FYA 71 44 58†
FYE 68 42 52†
† Includes spring and autumn emissions
Fractional NH3-N Loss, Great Plains Feedyards
Preece, S.L.M., N.A. Cole, R.W. Todd, and B.W. Auvermann. 2012. Ammonia emissions from cattle feeding operations. Texas A&M AgriLife Extension Service, E-632. College Station, TX.
LossNH3-N = 0.5 Nfed
EFNH3 = 88 lb head-1 yr-1
Conclusions
• Ammonia is significant loss of N from feedyards1/2 of fed N lost with optimum diets
• With a well-planned and managed feeding program, feedyard cattle emit ¼ lb NH3 per animal per day
• Previous emission factors underestimatedWe recommend an annual emission factor of 88 lb (40 kg) per animal (one-time capacity)
Questions?
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