Rangelands and GHG Calculators Peter R. Grace Queensland University of Technology Orange, NSW 19 November, 2008

Soil Carbon Sequestration Two principal approaches: Protecting ecosystems - Soil conservation Manage ecosystems Reduced tillage on croplands Increase inputs on degraded soils Convert to pasture Grazing management

Two principal approaches:

Protecting ecosystems - Soil conservation

Manage ecosystems

Reduced tillage on croplands

Increase inputs on degraded soils

Convert to pasture

Grazing management

Soil C Sequestration Overriding Influences Clay content Precipitation Temperature

Clay content

Precipitation

Temperature

Soil C vs CO 2 v Temperature vs H 2 O 6% loss in topsoil C by 2100 (Grace et al, 2006)

Soil C Sequestration Grazing Systems No definitive information - ambiguous Grazed systems > Ungrazed Grazing stimulates Aboveground growth Belowground growth Plant community changes Just as important not to promote C loss

No definitive information - ambiguous

Grazed systems > Ungrazed

Grazing stimulates

Aboveground growth

Belowground growth

Plant community changes

Just as important not to promote C loss

Global Dataset – Pasture Management

Predicted Soil C change (0-10 cm) 6 t/ha pasture Mudgee, NSW

Predicted Soil C change (0-10 cm) 3 t/ha crop Mudgee, NSW

Constraints to Soil C Accumulation in Grazing Systems Low water availability - Low biomass returns Low quality biomass High temperatures

Low water availability - Low biomass returns

Low quality biomass

High temperatures

Constraints to Claiming Credits Spatial variability Expensive to verify Permanence

Spatial variability

Expensive to verify

Permanence

Land Use

Soils

Potential Soil C Sequestration Rangelands (0-100 cm) *SOCRATES (Grace et al., 2006) 927 253 437 TOTAL 407 111 1.48 75 Vertosol 39 11 0.12 89 Tenosol 187 51 0.74 69 Sodosol 18 5 0.12 42 Rudosol 8 2 0.74 3 Kurosol 168 46 0.51 90 Kandosol 18 5 1.23 4 Ferrosol 19 5 0.74 7 Dermosol 43 12 0.74 16 Chromosol 18 5 0.12 42 Calcarosol Total Mt CO 2 Total Mt C C increase (t/annum) Area (Mha) Soil type

Actual (??) Soil C Sequestration Rangelands (0-100 cm) *SOCRATES (Grace et al., 2006) Methane oxidation < 1.0 Mt CO 2 9.3 2.53 43.7 TOTAL 4.07 1.11 0.15 7.5 Vertosol .39 .11 0.01 8.9 Tenosol 1.87 .51 0.07 6.9 Sodosol .18 .05 0.01 4.2 Rudosol .08 .02 0.07 0.3 Kurosol 1.68 .46 0.05 9.0 Kandosol .18 .05 0.12 0.4 Ferrosol .19 .05 0.07 0.7 Dermosol .43 .12 0.07 1.6 Chromosol .18 .05 0.01 4.2 Calcarosol Total Mt CO 2 Total Mt C C increase (t/annum) Area (Mha) Soil type

Main Sources of On-Farm GHGs CH 4 CO 2 , CH 4 , N 2 O CO 2 Soil type, climate and management specific

Anthropogenic Sources of Methane and Nitrous Oxide Globally Total Impact 2.0 Pg C equiv 1.2 Pg C equiv Source IPCC 2001; from Robertson 2004 (compare to fossil fuel CO 2 loading = 3.3 PgC per year) Industry Industry Agricultural soils Biomass burning Cattle & feedlots Agriculture Agriculture Energy Other combustion Landfills Enteric fermentation Waste treatment Rice cultivation Biomass burning CH 4 N 2 O

Greenhouse Gases – in brief 3 major gases = CO 2 , N 2 O, CH 4 CH 4 has global warming impact 23 X CO 2 N 2 O has global warming impact 296 X CO 2 CO 2 equivalents CO 2 e = 1 * CO 2 + 23 * CH 4 + 296 * N 2 O

3 major gases = CO 2 , N 2 O, CH 4

CH 4 has global warming impact 23 X CO 2

N 2 O has global warming impact 296 X CO 2

CO 2 equivalents

CO 2 e = 1 * CO 2 + 23 * CH 4 + 296 * N 2 O

Emissions Facts 1000 L diesel = 2.6 tonnes CO 2 Irrigation (ca. 3 tonnes CO 2 /ha) Cattle emit 60 kg CH 4 /yr = 1.4 tonnes CO 2 Dependent on feed quality and age of cattle 1 tonne N fert emits 5 kg N 2 O = 1.5 t CO 2 Residential electricity = 12 t CO 2 /annum

1000 L diesel = 2.6 tonnes CO 2

Irrigation (ca. 3 tonnes CO 2 /ha)

Cattle emit 60 kg CH 4 /yr = 1.4 tonnes CO 2

Dependent on feed quality and age of cattle

1 tonne N fert emits 5 kg N 2 O = 1.5 t CO 2

Residential electricity = 12 t CO 2 /annum

On-Farm GHG Emissions Fuel: CO 2 Cultivation: CO 2 Residue decomposition : CO 2 N 2 O Nitrogen application: N 2 O Burning crop residues: N 2 O CH 4 Biological N fixation: N 2 O Waterlogging CH 4 Animal emissions CH 4 Urine and dung N 2 O Manure management (feedlots) N 2 O CH 4

Fuel: CO 2

Cultivation: CO 2

Residue decomposition : CO 2 N 2 O

Nitrogen application: N 2 O

Burning crop residues: N 2 O CH 4

Biological N fixation: N 2 O

Waterlogging CH 4

Animal emissions CH 4

Urine and dung N 2 O

Manure management (feedlots) N 2 O CH 4

Greenhouse Gas Inventory Darling Downs 416 ha total 300 ha crop @ 84 kg N/ha 12 ha trees 100 head cattle

416 ha total

300 ha crop @ 84 kg N/ha

12 ha trees

100 head cattle

1 1.25% loss 154.0 Direct loss Fertiliser N 2 O 1 12.6 Dung and faeces 8.9 Dryland 492.5 TOTAL -47 Trees Sinks CO 2 138 Animals CH 4 106.4 Diesel 10.8 Petrol 0.2 Electricity Fuel/power CO 2 58.2 Irrigated 8.2 Dryland Soil CO 2 3.5 Leaching 12.2 Atmos. Deposit Other N 2 O 1 7.1 Irrigated cotton 19 Irrigated cereal 0 Pasture Crop N 2 O 1 Total CO 2 (e) (tonnes) Source Category

1 0.5% loss 61.5 Direct loss Fertiliser N 2 O 1 12.6 Dung and faeces 8.9 Dryland 431.5 TOTAL -47 Trees Sinks CO 2 138 Animals CH 4 106.4 Diesel 10.8 Petrol 0.2 Electricity Fuel/power CO 2 58.2 Irrigated 8.2 Dryland Soil CO 2 3.5 Leaching 12.2 Atmos. Deposit Other N 2 O 1 7.1 Irrigated cotton 19 Irrigated cereal 0 Pasture Crop N 2 O 1 Total CO 2 (e) (tonnes) Source Category

Nitrous oxide (N 2 O) Nitrogen gas emitted from added N sources Nitrogen fixation Nitrification (ammonium to nitrate) Denitrification (nitrate to nitrogen gases)

Nitrogen gas emitted from added N sources

Nitrogen fixation

Nitrification (ammonium to nitrate)

Denitrification (nitrate to nitrogen gases)

Portable Greenhouse Gas Monitoring

Global Greenhouse Gas Network

Reducing N 2 O Emissions - Benefits N 2 O reductions are immediate and permanent possible across a very wide range of crop lands and geographic areas

N 2 O reductions are

immediate and permanent

possible across a very wide range of crop lands and geographic areas

Greenhouse Gas Inventory Soil carbon change ( Gross C sequestration)

Soil carbon change ( Gross C sequestration)

Greenhouse Gas Inventory Soil carbon change ( Gross C sequestration) CO 2 from fuel (planting, cultivation, harvesting, chemicals)

Soil carbon change ( Gross C sequestration)

CO 2 from fuel (planting, cultivation, harvesting, chemicals)

Greenhouse Gas Inventory Soil carbon change ( Gross C sequestration) CO 2 from fuel (planting, cultivation, harvesting, chemicals) N 2 O from N fertilizer applied, N fixed and other N losses (leaching etc)

Soil carbon change ( Gross C sequestration)

CO 2 from fuel (planting, cultivation, harvesting, chemicals)

N 2 O from N fertilizer applied, N fixed and other N losses (leaching etc)

Greenhouse Gas Inventory Soil carbon change ( Gross C sequestration) CO 2 from fuel (planting, cultivation, harvesting, chemicals) N 2 O from N fertilizer applied, and other N losses N 2 O and CH 4 from burning

Soil carbon change ( Gross C sequestration)

CO 2 from fuel (planting, cultivation, harvesting, chemicals)

N 2 O from N fertilizer applied, and other N losses

N 2 O and CH 4 from burning

Greenhouse Gas Inventory Soil carbon change ( Gross C sequestration) CO 2 from fuel (planting, cultivation, harvesting, chemicals) N 2 O from N fertilizer applied, and other N losses N 2 O and CH 4 from burning CH 4 from animals Net carbon sequestration = 1 - (2+3+4+5)

Soil carbon change ( Gross C sequestration)

CO 2 from fuel (planting, cultivation, harvesting, chemicals)

N 2 O from N fertilizer applied, and other N losses

N 2 O and CH 4 from burning

CH 4 from animals

Net carbon sequestration = 1 - (2+3+4+5)

SE Australia Greenhouse Gas Assessment

Carbon Sequestration (no-till) South-East Australia (0-30 cm)

Calculator website www.isr.qut.edu.au

www.isr.qut.edu.au

Calculator website www.isr.qut.edu.au

www.isr.qut.edu.au

Take home messages! High temperatures, low rainfall - difficult environment to sequester significant carbon mass

High temperatures, low rainfall - difficult environment to sequester significant carbon mass

Take home messages! High temperatures, low rainfall - difficult environment to sequester significant carbon mass Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities

High temperatures, low rainfall - difficult environment to sequester significant carbon mass

Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities

Take home messages! High temperatures, low rainfall - difficult environment to sequester significant carbon mass Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities Verification and transaction costs are high

High temperatures, low rainfall - difficult environment to sequester significant carbon mass

Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities

Verification and transaction costs are high

Take home messages! High temperatures, low rainfall - difficult environment to sequester significant carbon mass Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities Verification and transaction costs are high Whole farming systems approach with all gases is ESSENTIAL

High temperatures, low rainfall - difficult environment to sequester significant carbon mass

Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities

Verification and transaction costs are high

Whole farming systems approach with all gases is ESSENTIAL

Take home messages! High temperatures, low rainfall - difficult environment to sequester significant carbon mass Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities Verification and transaction costs are high Whole farming systems approach with all gases is ESSENTIAL Increased N use efficiency is a must for reducing your greenhouse gas signature

High temperatures, low rainfall - difficult environment to sequester significant carbon mass

Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities

Verification and transaction costs are high

Whole farming systems approach with all gases is ESSENTIAL

Increased N use efficiency is a must for reducing your greenhouse gas signature

Take home messages! High temperatures, low rainfall - difficult environment to sequester significant carbon mass Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities Verification and transaction costs are high Whole farming systems approach with all gases is ESSENTIAL Increased N use efficiency is a must for reducing your greenhouse gas signature Maintaining soil C is key to long term productivity and profitability

High temperatures, low rainfall - difficult environment to sequester significant carbon mass

Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities

Verification and transaction costs are high

Whole farming systems approach with all gases is ESSENTIAL

Increased N use efficiency is a must for reducing your greenhouse gas signature

Maintaining soil C is key to long term productivity and profitability

Questions?