ammonia volatilization from wet animal manures c.w. wood, j.j. meisinger, p.a. moore, jr., and r.b....
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Ammonia Volatilization from Wet Animal Manures
C.W. Wood, J.J. Meisinger, P.A. Moore, Jr., and R.B. Thompson
Auburn University, USDA-ARS, Beltsville, MD and Fayetteville, AR
I. Problems With NH3 Volatilization
• Acid Atmospheric Deposition– raises pH of rainwater, more SO2 dissolves
– ammonium sulfate forms - oxidizes soil– releases sulfuric & nitric acid
• Eutrophication– water and land
• Loss of N to farmers• Lowers N:P
II. Sources of NH3 on Livestock Farms
• Manure Application• Animal Housing• Manure Storage• Grazing• Fertilizer Application• Crops
DescendingOrder ofImportance
Bussink & Oenema, 1998
0 5 10 15 20 25 30 35 40 45 50% DM
Liquid Semisolid Solid
Description Thin toThickSlurry
As Defecated PartiallyDried
Considerable
Drying
Water Water Added As Defecated Water Removed
HandlingPumped Scraped
LiquidHandling
Equipment
Semisolid or SolidHandling
Equipment
SolidHandling
Equipment
Loehr, 1974
A)
Time after slurry application (days)
0 2 4 6 8 10
NH
3em
issi
on (
kg N
ha-1
h-1)
0
1
2
3
4
5
6 B)
0 2 4 6 8 10N
H3e
mis
sion
, (kg
N h
a-1)
0
10
20
30
40
50
60
Leuning samplersFerm tubes
Pig Slurry; New Zealand; 368 kg N/ha applied
15.5% of NH4-N
IV. Factors Affecting NH3
Volatilization From Liquid Manures
B. Those That Affect Transfer of Gas Between Soil Solution
and the Atmosphere
Solution/Atmosphere Interface
• Mattila (1998) - cattle slurry - 0 NH3v with injection; band < broadcast
• Sommer and Ersboll (1994) - cattle and swine slurry- NH3v from injected slurry in tilled soil was 30% of that from unworked soil; harrowing before surface application reduced NH3v by 50%
• Sharpe & Harper (1997) - swine effluent -13% of TAN lost via spray drift, 69% more after settling
Solution/Atmosphere Interface
• Sommer et al. (1997) - pig slurry - trail hose application resulted in 1/2 TAN loss of splash plate application; trail hose more effective under large plant canopy and low solar radiation
Air Velocity
• Sommer et al. (1991) - cattle slurry
• NH3v rate increased to 2.5 m/sec; no change between 2.5 and 4 m/sec
• crust formation with increased wind speed may increase liquid phase resistance
Rainfall/Soil Moisture
• Beauchamp et al. (1982) - cattle slurry– rainfall depressed volatilization temporarily
• difficult to distinguish from effect of temperature (rainfall = lower temperature)
• may leach soluble ammoniacal N into soil
• Sommer et al. (1991) - cattle slurry– frozen soil prevented infiltration
– NH3v rate low, but constant - 6-day cumulative loss high
IV. Factors Affecting NH3
Volatilization From Liquid Manures
C. Those That Affect Rate of Chemical Reaction
NH3L NH3G KHN = [NH3G]/[NH3L]
NH4+
NH3 + H+ K = [NH3]x[H+]/[NH4
+]
CO2 + H2O HCO3 + H+
K = [HCO3]x[H+]/[CO2]
Basic Chemistry
Swine Waste TAN
TAN (% of TN)
Sharpe and Harper (1997) 81.5
Sommer and Ersboll (1994) 71.5
Hoff , Nelson & Sutton (1981) 48.3
Sommer et al (1997) 73.7
Cattle Waste TANTAN (% of TN)
Thompson and Meisinger (2002) 33.4
Sommer and Ersboll (1994) 59.7
Sommer et al. (1991) 59.9
Beauchamp et al. (1981) 54.2
Stevens et al. (1992) 57.5
Matilla (1998) 58.9
[ammoniacal N]• Brunke et al. (1988) - surface
applied swine and dairy slurries– linear relationship between ammonia
volatilization and [ammoniacal N]
• Frost (1994) - surface applied cattle slurry– amount of dilution water added was
linearly and inversely related to volatilization•dilution of 0.9-1.2:1 water:slurry lowered
specific volatilization/unit slurry by 50%
[ammoniacal N]• Stevens et al. (1992) - surface
applied cattle slurry– 50% decrease with separation through
10-mm mesh plus dilution with 86% by volume of water
– 75% decrease with separation through 5-mm mesh plus dilution with 100% by volume of water
Micro-meteorological studies
Two applications to arable land (corn stubble)
December 96
• 88 m3 ha-1
• 91 kg NH4+-N ha-1
April/May 97
• 38 m3 ha-1
• 51 kg NH4+-N ha-1
0
500
1000
1500
2000
2500
3000
3500
4000
10
20
30
0 24 48 72 96 120
Ra
te N
H3 lo
ss
(g
N h
a-1 h
r-1)
Air
te
mp
hours
Ammonia Loss from Cattle Slurry applied 30 April
Total 8 day loss = 71% of NH4+-N
• rate 38 m3 ha-1, • applied to corn stubble
• measured with MM
0
500
1000
1500
2000
2500
05
10
0 12 24 36 48 60 72 84hours
Rat
e N
H3 lo
ss (
gN
ha-1
hr-1
)A
ir te
mp
{
26 mm RF
11 mm RF
Total loss = 19% of NH4+-N
Ammonia Loss from Cattle Slurry applied 5 December
• rate 88 m3 ha-1, • applied to corn stubble
• measured with MM
Effect of Treatment on Manure pH
6
6.5
7
7.5
8
Control 0.25% 0.50% 0.75%
Man
ure
pH
Normal
Phytase
AR swine manure; 150 kg N/ha
Effect of Treatments on Ammonia Flux
0
20
40
60
80
100
120
Control 0.25% 0.50% 0.75%
AlCl3 Treatment
Am
mo
nia
Fu
x
(mg
NH
3 m
-2 h
r-1)
Normal
Phytase
AR swine manure; 150 kg N/ha; AlCl3 0-0.75%v
Ammonia Flux as a Function of Manure pH
y = 55.124x - 324.2
R2 = 0.72
0
20
40
60
80
100
120
6 6.5 7 7.5 8
Manure pH
Am
mo
nia
Flu
x (m
g N
H3 m
-2 h
r-1)
AR swine manure; 150 kg N/ha; AlCl3 0-0.75%v
Other Factors
• Soil CEC - minimum of 25 meq/100 g (Sharpe & Harper, 1995)
• Soil pH
• Atmospheric [NH3]
• Plant absorption
Summary• NH3 volatilization causes environmental problems
and economic losses to farmers
• NH3 volatilization from liquid animal manures is fast
• Exposure to the soil surface enhances NH3 volatilization from liquid animal manures
• Environmental factors have a large influence• [ammoniacal-N] probably has the greatest
influence
• Dilution and acidification can help control NH3 volatilization from surface applied wet animal manures
Research Needs
• A coordinated research program is needed on NH3v from wet manures that encompasses a wide range of manures, weather conditions, and soil-tillage systems. Databases developed from such a research program would contribute to improved estimates of NH3v and improved management techniques for wet manures.
• Research should include a continuum from source to atmosphere.