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.

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

III. Nature and Handling

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

Travelling Gun

Tank Spreaders

IV. Factors Affecting NH3

Volatilization From Liquid Manures

A. Time

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

[ammoniacal N]

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

Poultry Waste TAN

TAN (% of TN)

Witter (1991) fresh 13.4

anaerobic 48.3

[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

Temperature

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

pH

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.