Proceedings available at: http://www.extension.org/67611
We conducted a field study on corn to evaluate the effect of liquid dairy manure applied pre-plant (injection or surface broadcast with immediate or 3-day disk incorporation) or sidedressed at 6-leaf stage (injected or surface-applied) on emission of NH3 and N2O. Manure was applied at a rate of 6500 gal/acre, which supplied an average of 150 lb/acre of total N and 65 lb/acre of NH4-N. Ammonia emission was measured for 3 days after manure application using the dynamic chamber/equilibrium concentration technique, and N2O flux was quantified using the static chamber method at intervals of 3 to 14 days throughout the season. Ammonia-N losses were typically 30 to 50 lb/acre from pre-plant surface application, most of the loss occurring in the first 6 to 12 hours after application. Emission rates were reduced 60-80% by quick incorporation and over 90% by injection. Losses of N2O were relatively low (1 lb/acre or less annually), but pronounced peaks of N2O flux occurred from either pre-plant or sidedress injected manure in different years. Results show that NH3 emission from manure can be reduced substantially by injection or quick incorporation, but there may be some tradeoff with N2O flux from injection.
Manure Application Method and Timing Effects on Emission of Ammonia and Nitrous Oxide
1. Manure Application Method and
Timing Effects on Emission of
Ammonia and Nitrous Oxide
Bill Jokela, Carrie Laboski, and Todd Andraski
USDA-ARS, Dairy Forage Research Center, Marshfield, WI
Soil Science Dept., Univ. of Wisconsin, Madison, WI
Waste to Worth Conference
April 2-5, 2013. Denver, CO
2. Situation
• Ammonia losses from surface-applied manure can
be large, reducing manure N availability/economic
value and contributing to environmental problems
• Nitrous oxide (N2O) is a potent greenhouse gas
that can be released from manure
• Injection or quick tillage incorporation can reduce
NH3 loss but effect on N2O emissions is less clear.
• How do manure management variables (timing,
method, incorporation time) affect
– NH3 and N2O losses?
– N availability/fertilizer value for corn?
• Can sidedressed manure be a viable N source?
4. Objective
• Evaluate the effect of liquid dairy
manure application method and timing,
and time of incorporation on:
– Ammonia losses
– Nitrous oxide emissions
– Corn yield and manure N
availability/fertilizer N value
5. Field Site
• Marshfield, WI, Ag Research Station
• Withee silt loam
– Aquic Glossudalf
– Somewhat poorly drained, 0-2% slope
• Previous crop = corn
– New site each year
6. Treatments
• Pre-plant manure (mid- late May)
– Surface application with disk
incorporation
• Immediate (<1 h)
• 1-day
• 3-day (surface)
– Injection
• S-tine (Kongsgilde Vibro-flex)
• 15-inch spacing
• 2-3-inch diam. band , 4-6 in. deep
– All plots chisel plowed 3-5 days
after manure application
7. Treatments
• Sidedress manure (5-6 lf stage)
– Injection
• S-tine (Kongsgilde Vibro-flex)
with shields
• 30-inch spacing
• 4-6 inches deep
– Surface (Yr 2, 3, and 4)
• Fertilizer N
– 6 pre-plant rates
• 0 to 200 lb/acre
– Not evaluated for NH3 or N2O
10. NH3 emission measurement
– Dynamic chamber/equilibrium
concentration
• Svensson, 1994; Misselbrook and
Hansen, 2001
• 2 chambers, 1 ambient meter/plot
• 4 passive diffusion samplers (2 types)
in each chamber
– Started immediately after manure
application; continued through Day 3
– 6 measurement periods
• Approx. 0-1, 1-2.5, 2.5-6, 6-20, 20-30,
and 44-54 h after manure application
11. N2O flux measurement
– Static, vented chamber
– GRACEnet protocol
• Parkin and Venterea, 2010
– 2 chambers/plot
– Sampled approx. weekly May-Oct
• More frequently after manure or rain
• Less frequently late in season
– 3 samples/time (0, 30, 60 min.)
– Flux calculated by linear regression
15. Ammonia Emission
2009-2011 Avg.
0
5
10
15
20
25
30
35
40
45
50
0 10 20 30 40 50 60
CumulativeNH3Loss(lbN/acre)
Hoursafter Manure Application
CumulativeNH3 Loss
2009-2011 Average
PP-Inject
PP-Disk1 hr
PP-Disk3 day
SD-Inj
a
bc
b
c
B
0
1
2
3
4
5
6
7
8
0 10 20 30 40 50 60
NH3Emission(lbN/acreh)
Hoursafter Manure Application
NH3 Emission Rates
2009-2011 Average
PP-Inject
PP-Disk 1 hr
PP-Disk 3 day
SD-Inj
A
16. Ammonia Emission
• Most loss in first 6-12 hours after
application
• Total 3-day losses (3-yr average)
highest for surface application
• NH3 loss reduced by injection (>90%) or
immediate disk incorporation (75%)
19. N2O Emission
• Increase in N2O flux after manure
application at PP and/or SD
– Injection most pronounced
– 6 to 12-day lag time
• Low levels of N2O late July to Oct.
• Magnitude and timing (PP vs. SD) varied
by year
– May be explained by combination of rain
events/soil moisture, soil temperature, and
manure characteristics and N content
22. Fertilizer N Equivalence
• Varied by year
– Weather, soil conditions, actual manure
N rate
• General trend (4-year avg.) related to
time of incorporation
– Inject (52%) >> 1-hr or 1-day (37%) > 3-
day (34%) > None (sidedress, 32%)
23. Summary
• Highest NH3 loss from surface
application
– Greatly reduced by injection (>90%) or
immediate disk incorporation (75%)
• Most NH3 loss in first 6-12 hours
after application
– Quick incorporation important
• Fertilizer N equivalence varied but
highest for injection, less for delayed
incorporation
24. Summary
• Injection of manure most effective
at reducing NH3 losses… but also
increased N2O emissions
– N2O-N << NH3-N, so not economically
important; but environmentally important
as a greenhouse gas
– But a portion of NH3 emitted eventually
converted to N2O (1 %; IPCC, 2006), so
trade-off may be minimized
25. • Alternatives to S-tine injection
– Tillage incorporation, but consider
residue management and erosion/water
quality concerns
– Different injection techniques (injector
type, depth, etc.)
26. Summary
• Sidedress application of manure is a viable N
source for corn
– Another window of time for manure application
– Can use PSNT to determine rate
– Practical limitations
• Equipment: Injection or direct incorporation preferred
• Field issues: equipment turning, plant damage
• Data support recent changes to UWEX
manure N availability (N Fertilizer
Equivalence)
– 50% injected or broadcast incorporated <1 hr
– 40% broadcast incorporated 1 to 72 hr
– 30% broadcast incorporated >72 hr or not incorporated
27. Thank You
• Research sponsored by:
– USDA-ARS
– WI Corn Growers Assoc.
• Thanks to all the staff & students
that helped with field and lab work