Study Area: Central Valley, - LCA Food 2014lcafood2014.org/presentations/52.pdf · almond hull for dairy feed) ... % biomass to gasification ... O EF from intermittently flooded rice

Study Area: Central Valley, California, USA

Orchard Crop Distribution in California

• 14 tree crops with significant commercial production in CA, of which almost 800,000 ha (> 98%) in 3 species

• > 99% of these crops grown within Central Valley

Orchard Crop Distribution in California

Major determining factors for distribution related to economic sustainability

• Water availability/ cost• Soil quality/ crop needs• Land/ input cost• Yield/market value

Regionally specific inputs/ practices

LCA Model Assumptions

Input values representative or “typical” for CA

• Local scale variations cancel on large scales

• No significant orchard demographic pattern

Factors omitted:

• Orchard soil carbon storage

• Marketing, distribution, consumption

• Human labor

LCA Model AssumptionsModel perspective: orchard crop production

• Goal: inform orchard industry and policy decision makers

• Scope: nursery to processor (post-harvest) gate

• System Boundary: orchard lifespan (25-60 yrs)

• Functional Unit: land use (ha), product (kg)

• Impact Assessment: Global Warming Potential (GWP100)

AB32: GHG Cap-and-trade in CASigned into law 2006, took effect 2012

Goal: reduce GHG emissions to 1990 levels by 2020

GHG emission monitoring and enforceable compliance obligation (“cap”) since 2013- Implementation and enforcement by California Air

Resources Board (CARB)- Applies to emitters of 22,675 tonnes CO2e yr-1 or more- Different industries including ag to be “rolled in” gradually- Soon to include some major orchard postharvest facilities

Offset credits issued for quantifiable GHG reduction (but not in course of “business as usual”)

Credit: www.xkcd.com

LCA Model

Process-based, comprehensive

Management choices from input production to end-of-life phases potentially have large effects on results

Major Determining Factorsfor total life cycle GHG emissions

Orchard Productive Lifespan (Pistachio > Walnut > Almond)

Fertilizer Input(Pistachio > Walnut > Almond)

Irrigation Water Input/ Source(Pistachio > Walnut > Almond)

Biomass Accumulation/ Fate(Walnut > Pistachio > Almond)

Yield (Dry Mass)(Walnut > Almond > Pistachio)

Surface Water Energy, Irrigation Infrastructure

Energy/ GHG burden: pumping + infrastructure

• Surface water• Pumped

• California Aqueduct, Delta-Mendota Canal

• Gravity fed• Sierra snowpack,

reservoirs

Groundwater Depth

California Department of Water Resources

• 23 years of groundwater depth data points (test wells)

• Interpolation to assign values to entire Central Valley orchard production region

Orchard IrrigationEnergyRequirements

Crop and regionally specific

• Surface water• Pumped (aqueduct)• Gravity fed

• Groundwater depth

• System pressurization

Greenhouse Gas Credits• Entirely derived from photosynthetic activity

and subsequent biomass accumulation

• Displacement of fossil fuel based energy: “carbon neutrality” (i.e., biogenic pool)

• Displacement of other products (i.e., almond hull for dairy feed)

• Temporary storage in standing biomass

• Long-term storage in soil (i.e., belowground biomass, mulch, biochar)

Greenhouse Gas Credits• Entirely derived from photosynthetic activity

and subsequent biomass accumulation

• Displacement of fossil fuel based energy: “carbon neutrality” (i.e., biogenic pool)

• Displacement of other products (i.e., almond hull for dairy feed)

• Temporary storage in standing biomass

• Long-term storage in soil (i.e., belowground biomass, mulch, biochar)

0

20000

40000

60000

80000

100000

0 10 20 30 40 50 60

kg C

O2e

ha-1

Year

Almond

Walnut

Pistachio

Biomass Accumulation

Temporary carbon storage credit for avoided radiative forcing:

calculated using concept of Time Adjusted Warming Potential (TAWP) as an alternative to the IPCC standard Global Warming Potential (GWP)

Biomass Energy

Fossil fuel displacement: potential source of GHG reduction credits

Spatial relationships, conversion technology, biomass accumulation: major determinants

GHG Emission (GWP100)

-2000

-1000

0

1000

2000

3000

4000

Almond Walnut Pistachio

kg C

O2e

ha-1

yr-1

TemporaryStorageCredit

Co-productCredit

Emission

NetEmission

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

2.50

3.00


kg C

O2e

kg-1


OffsetCredit

Emissions

NetEmissions


-3.00E-04

-2.00E-04

-1.00E-04

0.00E+00

1.00E-04

2.00E-04

3.00E-04

4.00E-04

5.00E-04


kg C

O2e

kca

l-1


OffsetCredit

Emissions

NetEmissions


Walnut

GHG Emission (GWP100) by Management Category

Almond

Pistachio

Pest Mgmt

Nutrient Mgmt

Land Prep

Biomass Mgmt

Nursery

Irrigation

Pollination

Harvest

Hulling/ Shelling

Other

Sensitivity Analysis: Net GHG Emission

-3 -2 -1 0 1 2 3

BS4

BS6

BS5

BS8

BS3

ISE4

ISE3

ISS3

NS1

ISE1

ISS4

ISS2

ISS1

ISE2

ISS5

ISS6

NS2

BS2

BS1

BS7

% Output Change/ % Parameter Change

Par

amet

er

% biomass to gasificationbiomass power plant efficiencybiomass accumulation ratefertilizer application rate% using diesel pumps% using electric pumpsirrigation water use% under flood irrigation% under microsprinkler irrigation% under sprinkler irrigationirrigation energy intensityN2O soil emission factor% under drip irrigation% using surface water% using ground waterannual pruning mass removed% biomass burned in-field% annual tree loss/replacementplanting densitydistance to power plant

Direct grower controlPartial grower controlNo grower control

-40000

-20000

0

20000

40000

60000

80000

100000

1 3 5 7 9 11 13 15 17 19 21 23 25

kg C

O2e

ha-1

Year

Business as Usual

Scenario Range

Biomass Accumulation

Scenario Analysis: Net GHG Emission (Almond)

-6,000

-4,000

-2,000

0

2,000

4,000

6,000

8,000

10,000

12,000

kg C

O2e

ha-1

MeanBaUOther Scenarios

Maximum Biomass Energy Production

-6000

-5000

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000


kg C

O2e

ha-1

yr-1


Co-ProductCredit

Emissions

NetEmissions


-4.00

-3.00

-2.00

-1.00

0.00

1.00

2.00

3.00


kg C

O2e

kg-1


Co-ProductCredit

Emissions

Net Emission


-6.00E-04

-4.00E-04

-2.00E-04

0.00E+00

2.00E-04

4.00E-04

6.00E-04


kg C

O2e

kca

l-1


Co-ProductCredit

Emissions

NetEmissions

-80 -60 -40 -20 0

baseline

10%, 15 yr interval

25%, 15 yr interval

50%, 15 yr interval

10%, 30 yr interval

25%, 30 yr interval

50%, 30 yr interval

50%, 10 yr interval

Tonnes CO2e ha-1

Co-productCredit


Temporary storage vs co-product use credit tradeoffs: orchard biomass management

Conclusions

GHG reduction credits• Potential for growers to achieve GHG neutral or negative

status: carbon credit payments?

• Incentives to manage for yield and biomass production?

• Economic sustainability under adverse conditions?

Comparative assessment• Depends on point of view: land use, economic yield,

nutrition

• Best options for GHG reduction vary depending on productive lifespan, biomass accumulation, input demands

Thank you for your attention!

AcknowledgementsThe Almond Board of CaliforniaThe Pistachio Research Board

California Department of Food and AgricultureUC Davis Agricultural Sustainability Institute

G&F AgriservicesDixon Ridge Farms

UC Cooperative ExtensionDr. Ted Dejong

Dr. Louise FergusonDr. Bruce Roberts

Dr. Elena Agueron-Fuentes

Contact: [email protected], [email protected], [email protected]

mailto:[email protected]



• 453203 ha planted

• Widely distributed in Central Valley

• Productive on relatively wide range of soil conditions

• Mostly micro-irrigation, some flood

• 56 dry tonnes/ha biomass accumulation

Almond• Productive Lifespan: 25 years

• Typical yield: 2.3 tonne ha-1 yr-1


• Well-distributed in CV

• Requires reasonably high-quality, deep soil – often riparian

• Mostly micro-irrigation, some flood


Walnut• Productive Lifespan: 35 years



• Mostly confined to southern CV

• Productive on marginal, shallow soils

• Mostly drip and microsprinkler


Pistachio• Productive Lifespan: 60-100 yrs?


Carbon Flow in Almond

Scenario: 95% biomass to energy production via 3% gasification, 97% solid fuel, and 50% long-term sequestration

of biochar gasification co-product.

Scenario CodesScenario Description

M1 Business as Usual (BaU)

M2 Linear scenario combination resulting in maximum net emissions/energy use

M3 Linear scenario combination resulting in minimum net emissions/energy use

B1 BaU scenario with alternative biomass accumulation model

B2 BaU with hulls displacing straw instead of corn silage

B3BaU biomass utilization mix with 3% gasification power plants, accounting for gasification power plant efficiency

and assuming 50% biochar long-term sequestration

B4BaU biomass utilization mix with solid fuel power plants replaced by gasification plants, plant efficiency 37.2%, 0%

biochar sequestration

B5BaU biomass utilization mix with solid fuel power plants replaced by gasification plants, plant efficiency 37.2%, 50%

biochar sequestration

B6Maximum biomass utilization mix (including all clearing, pruning, shells, and processing waste biomass) with solid

fuel power plants replaced by gasification plants, plant efficiency 37.2%, 0% biochar sequestration

B7

Maximum biomass utilization mix (including all clearing, pruning, shells, and processing waste biomass) with solid

fuel power plants replaced by gasification plants, plant efficiency 37.2%, 0% biochar sequestration, transport

distance 0 km (on-site generation)

B8

Maximum biomass utilization mix (including all clearing, pruning, shells, and processing waste biomass) with solid

fuel power plants replaced by gasification plants, plant efficiency 37.2%, 50% biochar sequestration, transport

distance 0 km (on-site generation)

B9Maximum biomass utilization mix (including all clearing, pruning, shells, and processing waste biomass) with solid

fuel power plants, plant efficiency 25%, 50% biochar sequestration, transport distance 0 km (on-site generation)

B10 All biomass waste burned in-field.

I1 BaU with 100% diesel pump

I2 BaU with 100% electric pump

I3 BaU with 100% electric pump, 100% flood irrigation

I4 BaU with 100% electric pump, 100% microsprinkler irrigation

I5 BaU with 100% electric pump, 100% drip irrigation

I6 BaU with 100% electric pump, 100% sprinkler irrigation

I7 BaU with 100% diesel pump, 100% flood irrigation

I8 BaU with 100% diesel pump, 100% microsprinkler irrigation

I9 BaU with 100% diesel pump, 100% drip irrigation

I10 BaU with 100% diesel pump, 100% sprinkler irrigation

I11 BaU with 100% electric pump, 100% surface water

I12 BaU with 100% electric pump, 100% groundwater

I13 BaU with 100% electric pump, 50% surface and 50% ground water

I14 BaU with 100% diesel pump, 100% surface water

I15 BaU with 100% diesel pump, 100% ground water

I16 BaU with 100% diesel pump, 50% surface and 50% ground water

I17 100% diesel pump, 100% surface water, microsprinkler irrigation

I18 100% electric pump, 100% ground water, flood irrigation

N1IPCC Tier 1/2; direct N2O EF data from Alsina and Smart (2010), indirect N2O via NH3 EF data from Krauter and Goorahoo (2000), indirect N2O via

NOx EF data from Matson (1997), flood direct N2O EF from intermittently flooded rice field data (IPCC 2006)

N2IPCC Tier 1/2; direct N2O EF data from Alsina and Smart (2010), indirect N2O via NH3 EF as IPCC (2006) default, indirect N2O via NOx EF data from

Matson (1997), flood irrigation direct N2O EF from intermittently flooded rice field data (IPCC 2006)

N3 IPCC Tier 1 default values (IPCC 2006)

N4

IPCC Tier 2/3; direct N2O EF data from Alsina and Smart (2010), indirect N2O via NH3 EF data from Krauter and Goorahoo (2000), indirect N2O via

NOx EF data from Matson (1997), flood irrigation direct N2O EF from intermittently flooded rice field data (IPCC 2006), drip irrigation direct N2O EF

directly measured

O1 Population-based model from OFFROAD software (CARB 2006)

E1 Electricity Supply Mixer - WECC Production eGrid05

E2 GREET

E3 Electricity, at grid, California|US|UCSB|agg - LCI result

E4 electricity, power supply, at grid, California Mix|US|EcoInvent/CA mix|agg - LCI result

E5 electricity, power supply, at power plant, California Mix|US|EcoInventCA mix|agg - LCI result

Sensitivity Parameter CodesParameter Description

NS1 N2O soil emission factor (kg N2O emitted/kgN applied)

NS2 fertilizer application (kg N applied/ha-yr)

ISS1 percent orchard area under flood irrigation

ISS2 percent orchard area under microsprinkler irrigation

ISS3 percent orchard area under drip irrigation

ISS4 percent orchard area under sprinkler irrigation

ISS5 percent orchard area using electric pumps

ISS6 percent orchard area using diesel pumps

ISE1 irrigation energy intensity (MJ/m3)

ISE2 irrigation water use (m3/ha-yr)

ISE3 percent orchard area using surface water

ISE4 percent orchard area using ground water

BS1 biomass-fueled power plant efficiency (MJ produced/MJ feedstock)

BS2 biomass accumulation (kg/ha-yr)

BS3 pruning removal (kg/ha-yr)

BS4 distance to power plant (km)

BS5 percent annual tree loss and replacement

BS6 planting density (trees/ha)

BS7 percent biomass waste directed to gasification-based energy generation

BS8

Documents

Study Area: Central Valley, - LCA Food 2014lcafood2014.org/presentations/52.pdf · almond hull for dairy feed) ... % biomass to gasification ... O EF from intermittently flooded rice