On-farm Greenhouse Gas Mitigation Practices

Julie DollW.K. Kellogg Biological Station &

Dept. of Plant, Soil and Microbial SciencesMichigan State University

jedoll@msu.edu

Paustian et al., 2006

On-farm “Climate Smart Agriculture”

Julie DollW.K. Kellogg Biological Station &

Dept. of Plant, Soil and Microbial SciencesMichigan State University

jedoll@msu.edu

Paustian et al., 2006

On-farm “Climate Smart Agriculture”

Julie DollW.K. Kellogg Biological Station &

Dept. of Plant, Soil and Microbial SciencesMichigan State University

jedoll@msu.edu

Paustian et al., 2006

Roadmap

• Three biogenic greenhouse gases• Mitigation practices on the farm – field crops• Systems approach

The three major biogenic greenhouse gases- are all affected by agriculture

(Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013, EPA 2015)

U.S. greenhouse gas emissions in 2013(carbon dioxide-equivalents)

Global Warming Potential: combined effect of atmospheric lifetime and ability to absorb heat• Carbon dioxide (CO2) GWP = 1• Methane (CH4) GWP = 23• Nitrous oxide (N2O) GWP = 296

Carbon dioxide-equivalents: units that represent the relative impact of a gas on atmospheric warming

Agricultural emissions in the United States

(EPA’s US GHG Inventory Report, 2014)

Does not include land cover change or other aspects of the food system, such as transportation.

Mitigation

(WICCI, 2011)

The idea that we can avoid, prevent or minimize undesirable things happening in the future.

1. Release fewer greenhouse gasesto the atmosphere

1. REMOVE greenhousegases from the atmosphere

Cropland in the U.S.

(Adapted from USDA, 2014)

(Robertson et al., 2015)

Importance to farmers of environmental benefitsprovided by agriculture

N=1800 Michigan corn-soy farmers. (Jolejole 2009; Lupi 2009)

Co-benefits of mitigation practices

• Stewardship goals

• Saving money

• Improving yields

• Increasing resilience to climate variability

• Adapting to climate change

Carbon dioxide (CO2) sources in the U.S.

(Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013, EPA 2015)

Mitigating carbon dioxide on the farm

• Whole farm energy use• Fertilizer production (Haber-Bosh process)• Other farm inputs (lime, pesticides, seeds)

Technologies and practices to mitigate• Improve electric service systems in rural areas• Energy efficiency improvements• Renewable energy generation

(USDA Building Blocks)

Mitigating carbon dioxide on the farm

• Soil carbon storage and conservation (“carbon sink”)

• 40-60% of original soil carbon lost after 40-60 years of cultivation in our region of North America

How to restore soil carbon?

1. Increase carbon inputs to soil

2. Decrease carbon loss from soil (slow decomposition)

•Cover crops•Rotations•Residue management

•Reduce tillage•Residue quality

Annual Crops (Corn - Soybean - Wheat)Conventional tillageNo-tillReduced-input with legume & rye cover cropsOrganic with legume & rye cover crops

Unmanaged FieldsEarly successional “old field”

Kellogg Biological StationLong-term Ecological Research (KBS LTER)

ChemicalIntensity

HIGH

LOW

(www.lter.kbs.msu.edu)

Restoring soil carbon – KBS cropping systems 12 years after establishment

(Syswerda et al., 2011)

Potential for recovering soil carbon

(Lal 1999, Smith 2004, IPCC 2002, Grace et al. 2006)

Eight years of accumulated C from CRP land is lost with a single tillage event

(Ruan and Robertson 2013)

But stored soil carbon is vulnerable to loss!

Methane (CH4) sources in the U.S.

(EPA, 2014)

Mitigating methane on the farm

Reduce production(methanogenesis):

Increase consumption(oxidation):

Mitigation technologies and practices:• Anaerobic digesters • Lagoon and waste storage covers with flaring• Enhanced solid separation

(USDA Building Blocks)

Nitrous oxide (N2O) sources in the U.S.

(EPA, 2014)

Inorganic NITROGEN

Nitrous oxide

Microbial processes: nitrification & denitrification

0

50

100

150

200

250

300

May Jun Jul Aug Sep Oct Nov

g N

2O-N

ha-

1 d-1 CT

NTrain

rain

rain

raintillage

sidedress N

planting N

Continuous corn

(Ruan & Robertson 2013)

Fertilizer and rainfall are drivers of N2O emissions

Nitrous oxide has a nonlinear response to N fertilizer

(Adapted from Millar and Robertson, 2015)

Yields do not increase beyond an N rate threshold

(Adapted from Millar and Robertson, 2015)

(Adapted from Millar and Robertson, 2015)

Environmental credit: tons of CO2-equivalents per acre

Reducing N2O emissions while maintaining yields

• Reduces agricultural greenhouse gases• Reduces reactive nitrogen in environment (including nitrate)

Current Status• Protocol now registered• Being marketed by aggregators• First credit issued June 2014 to

Michigan farmer Myron Ortner, then sold to the Climate Trust

Paying farmers for mitigation:MSU-EPRI Nitrous Oxide Reduction Protocol

(Millar et al., 2012, 2013)

Pays farmers for applying nitrogen fertilizer more precisely (4 “R’s”)

http://www.deltanitrogen.org

Ryan Smith: rsmith@delta-institute.org

A systems approach to greenhouse gas mitigation on the farm

Paustian et al., 2006

NPKLimeFuelSeedsPesticidesN2O

SOC

Ecosystem

Conventional No-till Low-input Biological-200

-150

-100

-50

Glo

bal W

arm

ing

Impa

ct (g

CO2e

q m

-2 y

r-1)

0

20

40

60

80

100

120

(Gelfand and Robertson, 2015; Gelfand et al., 2013)

Global warming impact of agricultural practices at KBS

Contributes to climate change

Mitigates climate change

Conventional No-till Low input OrganicConventiona

(Robertson et al., 2015)

Net global warming impact of KBS cropping systems

Contributes to climate change

Mitigates climate change

Organic

ReducedInput

No-till

Conventional

USDA Resources: Greenhouse gas report

(Eve et al., 2014)http://www.usda.gov/oce/climate_change/estimation.htm

USDA Resources: COMET-Farm

(Eve et al., 2014)

http://cometfarm.nrel.colostate.edu

Combining a landowners’ crop, livestock and forest management activities into a seamless greenhouse gas estimate for the entity.

Summary

1. Carbon dioxide mitigated (soil carbon stored) by:• Permanent no-till• Cover crops

2. Nitrous oxide mitigated by:• Any “4R” practices that reduce nitrogen inputs

• Better fertilizer recommendation• Variable rate application• Spring (not fall) fertilizer application

• In the future: nitrification inhibitors

Summary, con’t

3. Systems approach to mitigation helpful– Shows tradeoffs

4. Mitigation on the farm = climate smart agriculture = smart agriculture

– Co-benefits to mitigation: adaptation and resilience

Thanks!