Best management practices for nitrogen in intensive pasture

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The Carbon Farming Initiative and
Agricultural Emissions
This presentation was prepared by the University of
Melbourne for the Regional Landcare Facilitator training
funded through the Australian Government’s Carbon Farming
Initiative Communications Program
PART 8: OPTIONS FOR ABATEMENT
– EMISSION REDUCTION
This presentation provides options to reduce methane
and nitrous oxide emissions from agricultural systems
Options for abatement - Methane
Technologies to Reduce
Enteric Methane Emissions
Animal
Manipulation
Diet
Manipulation
Rumen
Manipulation
Forage
quality
Animal
Breeding
Residual Feed
Intake
Biological
Control
Plant
Breeding
Bacteriophages
bacteriocins
Efficiency
Reductive
Acetogenesis
Dietary
Supplements
Management
Systems
Dietary Oils
Alternative
livestock systems
Vaccination
Probiotics
Unproductive
Animals
Enzymes
Chemical
Defaunation
Dicarboxylic
acids
Plant Secondary
Compounds
Tannin &
Saponin
Eckard 2008
Options for abatement - Methane
Mitigation %
“Silver bullet”
45
40
35
30
25
20
15
10
5
0
Biological control
Vaccination
Dietary
Supplements
Rumen manipulation
Breeding
BMPs
Herd Management
Low
Immediate
High
Medium
Likely
Impact
High
Timeline
Longer Term
Confidence
Low
Eckard, Grainger & de Klein 2010
Options for abatement - Methane
• Measurement – in vitro
– Test tubes
– Continuous Culture
AgResearch, New Zealand
Options for abatement - Methane
• Measurement
– SF6 (sulphur hexafluoride)Tracer
• Individual animals in the field
Permeation tubes
Evacuated yolk/canister
Grainger, Eckard et al. 2007
Options for abatement - Methane
• Measurement
– Chambers/Calorimeters
• Individual Animals
Grainger, Eckard et al. 2007
Options for abatement - Methane
• Measurement
Reflector
– Open Path laser or FTIR tracer
Wind
Reflector
FTIR
Laser
FTIR
Griffiths et al. 2007; Phillips et al. 2009
Options for abatement - Methane
• Short term
– Feed quality
• Pasture improvement
• C3 pastures, legumes
– Dietary supplements
• Grain
• Tannins
• Oils
– 1% fat = 3.5% decrease CH4 /kg DMI
Eckard et al. 2010; Moate et al. 2010
Options for abatement - Methane
• Short term
– Improving farm efficiency / animal numbers
• Extended lactation
• Earlier finishing of beef
• Reproduction, weaning percentages, fertility &
health
– Alternative livestock systems
• Monogastrics & kangaroos?
– Pigs & chooks cannot covert grass into food
Eckard et al. 2010
Options for abatement - Methane
• Medium Term
– Animal Breeding
• Feed conversion efficiency
• Reduced methanogenesis
– Plant Breeding
• Improved energy to protein ratio
• Tannin, oils, sugars
Eckard, Grainger & de Klein 2010
Options for abatement - Methane
• Longer-term
– Rumen manipulation/ biological control
•
•
•
•
Vaccination
Competitive or predatory microbes
Acetogenesis (Kangaroo)
Succinate (Tamar Wallaby)
Eckard, Grainger & de Klein 2010
Options for abatement – N2O
Technologies to reduce
Nitrous Oxide emissions
Animal
Soils
Physical
interventions
Restricted
Grazing
Feed Conversion
Efficiency
Breeding
Plant breeding
eg. tannins
Dietary
Interventions
Chemical
Intgerventions
Balancing
Protein: Energy
Salt
Nitrification
inhibitor in urine
Fertiliser
Rate
Waterlogging /
drainage
Source
Irrigation
Timing
Compaction
Effluent
Management
Controlled
Release
Nitrification
Inhibitors
Eckard 2008
Options for abatement – N2O
“Silver bullet”
25
Biological control
Animal
Breeding
Mitigation %
20
15
Nitrification
Inhibitors
10
BMPs
5
Diet
Plant
Breeding
Soil Microbial
Manipulation
Secondary plant
compounds
Herd Management
0
Low
Immediate
High
Likely
Impact
Medium
High
Timeline
Longer Term
Confidence
Low
De Klein & Eckard 2008
Options for abatement – N2O
• Measurement of N2O
– Manual and automatic chambers
Options for abatement – N2O
• Measurement of N2O
– Micrometeorological methods
Options for abatement – N2O
• Short term - Nitrogen Fertiliser Rate
• Match to plant demand
• Similar with effluent
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Environment
11.7
8.1
30
Annual N2O emission (kg N/ha.y)
Predicted Pasture Growth (t DM/ha.y)
Productivity
13.3
6.0
8.5
11.2
Urea
Nitrate
Urea
Nitrate
25
20
15
10
5
0
0
100
200
300
400
500
600
Annual N Fertiliser Rate (kg N/ha.y)
700
800
900
0
100
200
300
400
500
600
Nitrogen Fertiliser Rate (kg N/ha.y)
Eckard et al. 2006
Options for abatement – N2O
• Short term - Nitrogen fertiliser rate
Nitrous oxide-N (kg/ha)
10
Cotton
8
Wheat-VetchCotton
Wheat-Cotton
6
4
2
0
0
100
N rate
200
300
Grace et al. 2007
Options for abatement – N2O
• Short term - Choice of N Source
• In wet soils
– N2O (nitrous oxide) from NO3-N (nitrate) source
– Denitrification or leaching
• In dry soils
– N Placement
• Band, ridges
• Within paddock
Annual N2O emission (kg N/ha.y)
– N2O (nitrous oxide) from NH3 (ammonia)
30
– Volatilisation from urea
Urea
25
Nitrate
20
15
10
5
0
0
100
200
300
400
500
600
Nitrogen Fertiliser Rate (kg N/ha.y)
Eckard et al. 2006
Options for abatement – N2O
• Short term - N Source and timing
1.8
Control
Ammonium nitrate
Urea
1.6
1.4
Nitrous Oxide loss (kg N/ha)
1.2
1.0
0.8
0.6
0.4
0.2
0.0
Autumn
Winter
Spring
Summer
Eckard et al. 2002
Options for abatement – N2O
• Short term - Fertiliser formulation
– Urease inhibitors
• Reduces NH3 (ammonia) volatilisation
– eg. Agrotain®, Green UreaTM
– Nitrification inhibitors
• Reduces N2O (nitrous oxide) and ENTEC®
NO3 (nitrate) leaching
• Temperature sensitive
– eg. DCD, Nitrapyrin, DMPP
De Klein & Eckard 2008
Options for abatement – N2O
• Short term - N formulation
– Nitrification Inhibitor sprays on pasture
• 50% less N2O
– for 50 days mid-spring
• 25% less N2O
– for 25 days in summer
Kelly et al;. 2008
Options for abatement – N2O
• Short term - N formulation
– Controlled Release/Coated Fertilisers
• Polymer or oil-based coating
– Controlled pattern/rate of release
– Slow Release Fertilisers
• Reduced solubility
– Chemical
– Physical mixing
• Slower release of N
De Klein & Eckard 2008
Options for abatement – N2O
• Short term – Soil Water / irrigation
Granli and Bøckman (1994)
Options for abatement – N2O
• Short term - Soil Management
– Limited grazing on wet soils/ use of feedpads
– Soil structure
• Reduce waterlogging with N
• Reduce soil compaction with N
– Stubble management
• Retain stubble
• Conservation tillage and controlled traffic
• Build soil organic matter
– Reduce fallow
• Loss of unutilised N
• Cover crops
De Klein & Eckard 2008
Options for abatement – N2O
• Medium term
– Plant breeding
• Tannin content
• Less N required
• Longer term
– Rumen manipulation
– Soil microbial manipulation
– Animal breeding
• More N efficient
“Silver bullet”
25
Biological control
Animal
Breeding
Mitigation %
20
15
Nitrification
Inhibitors
10
BMPs
5
Diet
Plant
Breeding
Soil Microbial
Manipulation
Secondary plant
compounds
Herd Management
0
Low
Immediate
High
Likely
Impact
Medium
High
Timeline
Longer Term
Confidence
Low
De Klein & Eckard 2008
Options for abatement – N2O
• Urine Management
• Ruminants excrete 75 to 95% of N intake
• Short Term
– Balancing ME:CP
– Feed tannins
– Animal numbers
• Reduce hot-spots
– Inhibitors
• Longer Term
– Breeding
• Improve animal FCE
• Improve plant
– ME:CP
– tannins
• Inhibitor spray
Grainger et al. 2009; De Klein & Eckard 2008
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