Study Area: Central Valley, California, USA

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 Assumptions Model 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 (GWP 100 )

Offset credits issued for quantifiable GHG reduction (but not in course of business as usual ) AB32: GHG Cap-and-trade in CA Signed 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 CO 2 e yr -1 or more - Different industries including ag to be rolled in gradually - Soon to include some major orchard postharvest facilities

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LCA Model Process-based, comprehensive Management choices from input production to endof-life phases potentially have large effects on results

Major Determining Factors for 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 Irrigation Energy Requirements 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)

Biomass Accumulation kg CO 2 e ha -1 100000 80000 60000 40000 20000 Almond Walnut Pistachio Year 0 0 10 20 30 40 50 60 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 (GWP 100 ) kg CO 2 e ha -1 yr -1 4000 3000 2000 1000 0-1000 -2000 Almond Walnut Pistachio Temporary Storage Credit Co-product Credit Emission Net Emission

GHG Emission (GWP 100 ) kg CO 2 e kg -1 3.00 2.50 2.00 1.50 1.00 0.50 0.00 Temporary Storage Credit Offset Credit Emissions -0.50-1.00-1.50 Almond Walnut Pistachio Net Emissions

GHG Emission (GWP 100 ) kg CO 2 e kcal -1 5.00E-04 4.00E-04 3.00E-04 2.00E-04 1.00E-04 0.00E+00-1.00E-04-2.00E-04-3.00E-04 Almond Walnut Pistachio Temporary Storage Credit Offset Credit Emissions Net Emissions

GHG Emission (GWP 100 ) by Management Category Almond Walnut Pest Mgmt Nutrient Mgmt Land Prep Biomass Mgmt Nursery Irrigation Pistachio Pollination Harvest Hulling/ Shelling Other

Parameter Sensitivity Analysis: Net GHG Emission -3-2 -1 0 1 2 3 % Output Change/ % Parameter Change BS7 BS1 BS2 NS2 ISS6 ISS5 ISE2 ISS1 ISS2 ISS4 ISE1 NS1 ISS3 ISE3 ISE4 BS3 BS8 BS5 BS6 BS4 % biomass to gasification biomass power plant efficiency biomass accumulation rate fertilizer application rate % using diesel pumps % using electric pumps irrigation water use % under flood irrigation % under microsprinkler irrigation % under sprinkler irrigation irrigation energy intensity N2O soil emission factor % under drip irrigation % using surface water % using ground water annual pruning mass removed % biomass burned in-field % annual tree loss/replacement planting density distance to power plant Direct grower control Partial grower control No grower control

Scenario Analysis: Net GHG Emission 12,000 10,000 Mean BaU Other Scenarios 8,000 (Almond) 6,000 kg CO 2 e ha -1 100000 80000 60000 40000 20000 0 Business as Usual Scenario Range Biomass Accumulation kg CO 2 e ha -1 4,000 2,000 0-2,000-4,000-20000 -6,000-40000 1 3 5 7 9 11 13 15 17 19 21 23 25 Year

Maximum Biomass Energy Production kg CO 2 e ha -1 yr -1 4000 3000 2000 1000 0-1000 -2000-3000 -4000-5000 Temporary Storage Credit Co-Product Credit Emissions Net Emissions -6000 Almond Walnut Pistachio

Maximum Biomass Energy Production 3.00 2.00 Temporary Storage Credit kg CO 2 e kg -1 1.00 0.00-1.00-2.00-3.00 Co-Product Credit Emissions Net Emission -4.00 Almond Walnut Pistachio

Maximum Biomass Energy Production 6.00E-04 4.00E-04 Temporary Storage Credit kg CO 2 e kcal -1 2.00E-04 0.00E+00-2.00E-04-4.00E-04 Co-Product Credit Emissions Net Emissions -6.00E-04 Almond Walnut Pistachio

Temporary storage vs co-product use credit tradeoffs: orchard biomass management Co-product Credit Temporary Storage Credit 50%, 10 yr interval 50%, 30 yr interval 25%, 30 yr interval 10%, 30 yr interval 50%, 15 yr interval 25%, 15 yr interval 10%, 15 yr interval baseline -80-60 -40-20 0 Tonnes CO 2 e ha -1

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!

Acknowledgements The Almond Board of California The Pistachio Research Board California Department of Food and Agriculture UC Davis Agricultural Sustainability Institute G&F Agriservices Dixon Ridge Farms UC Cooperative Extension Dr. Ted Dejong Dr. Louise Ferguson Dr. Bruce Roberts Dr. Elena Agueron-Fuentes Contact: emarvinney@ucdavis.edu, amkendall@ucdavis.edu, sbbrodt@ucdavis.edu

Almond 453203 ha planted Widely distributed in Central Valley Productive on relatively wide range of soil conditions Mostly microirrigation, some flood 56 dry tonnes/ha biomass accumulation Productive Lifespan: 25 years Typical yield: 2.3 tonne ha -1 yr -1

Walnut 132614 ha planted Well-distributed in CV Requires reasonably high-quality, deep soil often riparian Mostly microirrigation, some flood 76 dry tonnes/ha biomass accumulation Productive Lifespan: 35 years Typical yield: 3.4 tonne ha -1 yr -1

Pistachio 72839 ha planted Mostly confined to southern CV Productive on marginal, shallow soils Mostly drip and microsprinkler 65 dry tonnes/ha biomass accumulation Productive Lifespan: 60-100 yrs? Typical yield: 1.6 tonne ha -1 yr -1

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 Codes Scenario 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 B3 B4 B5 BaU biomass utilization mix with 3% gasification power plants, accounting for gasification power plant efficiency and assuming 50% biochar long-term sequestration BaU biomass utilization mix with solid fuel power plants replaced by gasification plants, plant efficiency 37.2%, 0% biochar sequestration BaU biomass utilization mix with solid fuel power plants replaced by gasification plants, plant efficiency 37.2%, 50% biochar sequestration B6 B7 B8 B9 B10 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 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) 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) Maximum 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) All biomass waste burned in-field.

I1 I2 I3 I4 I5 I6 I7 I8 I9 I10 I11 I12 I13 I14 I15 I16 I17 I18 N1 BaU with 100% diesel pump BaU with 100% electric pump BaU with 100% electric pump, 100% flood irrigation BaU with 100% electric pump, 100% microsprinkler irrigation BaU with 100% electric pump, 100% drip irrigation BaU with 100% electric pump, 100% sprinkler irrigation BaU with 100% diesel pump, 100% flood irrigation BaU with 100% diesel pump, 100% microsprinkler irrigation BaU with 100% diesel pump, 100% drip irrigation BaU with 100% diesel pump, 100% sprinkler irrigation BaU with 100% electric pump, 100% surface water BaU with 100% electric pump, 100% groundwater BaU with 100% electric pump, 50% surface and 50% ground water BaU with 100% diesel pump, 100% surface water BaU with 100% diesel pump, 100% ground water BaU with 100% diesel pump, 50% surface and 50% ground water 100% diesel pump, 100% surface water, microsprinkler irrigation 100% electric pump, 100% ground water, flood irrigation IPCC Tier 1/2; direct N 2 O EF data from Alsina and Smart (2010), indirect N 2 O via NH 3 EF data from Krauter and Goorahoo (2000), indirect N 2 O via NO x EF data from Matson (1997), flood direct N 2 O EF from intermittently flooded rice field data (IPCC 2006) IPCC Tier 1/2; direct N 2 O EF data from Alsina and Smart (2010), indirect N 2 O via NH 3 EF as IPCC (2006) default, indirect N 2 O via NO x EF data from N2 Matson (1997), flood irrigation direct N 2 O EF from intermittently flooded rice field data (IPCC 2006) N3 IPCC Tier 1 default values (IPCC 2006) IPCC Tier 2/3; direct N 2 O EF data from Alsina and Smart (2010), indirect N 2 O via NH 3 EF data from Krauter and Goorahoo (2000), indirect N 2 O via NO x EF data from Matson (1997), flood irrigation direct N 2 O EF from intermittently flooded rice field data (IPCC 2006), drip irrigation direct N 2 O EF N4 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 Codes Parameter Description NS1 NS2 ISS1 ISS2 ISS3 ISS4 ISS5 ISS6 ISE1 irrigation energy intensity (MJ/m 3 ) ISE2 irrigation water use (m 3 /ha-yr) ISE3 ISE4 BS1 BS2 biomass accumulation (kg/ha-yr) BS3 pruning removal (kg/ha-yr) BS4 distance to power plant (km) BS5 BS6 planting density (trees/ha) BS7 N 2 O soil emission factor (kg N 2 O emitted/kgn applied) fertilizer application (kg N applied/ha-yr) percent orchard area under flood irrigation percent orchard area under microsprinkler irrigation percent orchard area under drip irrigation percent orchard area under sprinkler irrigation percent orchard area using electric pumps percent orchard area using diesel pumps percent orchard area using surface water percent orchard area using ground water biomass-fueled power plant efficiency (MJ produced/mj feedstock) percent annual tree loss and replacement percent biomass waste directed to gasification-based energy generation