Impacts of Biochar Additions on Agronomic Yields

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Impacts of Biochar Additions on Agronomic Yields

• Kurt Spokas
• USDA-ARS, Soil and Water Management Unit, St.
  Paul, MN
• Adjunct Professor University of Minnesota
  Department of Soil, Water and Climate

Illinois Biochar Group Meeting ISTC June 9, 2011
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Biochar Soil Application

• The assumed target for biochar has been soil
  application
• Focus has been on creating Terra Preta soils

Observations of increased soil fertility and
productivity. Postulated from slash and burn
historic charcoal additions
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Biochar Soil Application

• However, on the other side
• Wood distillation plants 1800-1950s
• Wood pyrolysis source of chemicals and energy
  prior to petroleum (fossil fuel)
• Multiple large plants existed (10 cords ?14
  tons per day)
• Some plants on US-EPA Superfund site list
• Other charcoal sites
• Not always productive
• Reduced seed germination
• Reduced plant growth

(BEGLINGER AND LOCKE, 1957)
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Soil Application Long History

• Applications date back to the beginning of modern
  science 1800s

(LeFroy, 1883)
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Biochar Soil Application

• Does biochar improve agronomic yields?

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Biochar Soil Application

• Recent compilation of historical and recent
  biochar (black carbon) applications

• 50 positive,
• 30 no effect, and
• 20 negative impacts on growth and/or yield
• (Spokas et al., 2011)
• However, should not be used as a basis for
  forecasting outcomes ? Publication bias
• (Møller and Jennions, 2001)

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Further Observations from Existing Studies

• Wood Feedstock
• Majority of observed positive yield improvements
  have used wood feedstock with traditional soil
  kiln/fire pit methods (not pyrolysis units)
• Other feedstocks
• negative to no impact
• Exception Poultry manure (higher N-content)

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Significant Hurdles

• Lack of adequate documentation of biochar
  properties and conditions in existing studies
• Existing feeling that biochar biochar
• Once produced Biochar is reactive
• Surface chemistry is not only a function of
  production and feedstock, but also of
  post-production conditions and storage (i.e.
  cooling method, activation)
• Biochars with equivalent production conditions
  still can be chemically and structurally
  different

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Sorbed Organics on Oak Biochar
Slow pyrolysis
Equivalent production conditions
Slow pyrolysis
Fast pyrolysis
Gasifier pyrolysis
Soil kiln mound (traditional)
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Active Biochar Research

• MN Corn Growers Association
• gt Examining the potential use of microwave
  assisted pyrolysis in the conversion of
  distillers grain into value added products
  (energy, bio-oil and biochar)
• MN Dept. of Agriculture (Specialty Crop Block
  Grant)
• gt Impacts of biochar on specialty crop
  production
• - Soil and yield impacts
• - Potential bioaccumulation of other organic
  compounds on biochar
• USDA-ARS
• gt Rosemount, MN Field Plots 8 different
  biochars biomass
• gt Laboratory assessments of GHG and VOC impacts

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Conclusions

• Despite the long research history
• No absolute biochar consistent trends
• Highly variable material
• Production post-production handling
• Different responses to biochar
• Function of soil ecosystem (microbial linkage)
  position on black carbon continuum
• Importance of fully documenting methods of
  creation, handling, and properties
• Allow future elucidation of factors
• Several inter-related mechanisms
• Biochar does act as a carbon sequestration agent
• As long as biochar has low oxygen to carbon (OC)
  molar ratio

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Looking Forward

• Economics caused the shift from biomass to fossil
  fuels in the early 1920s
• We at the cusp where environmental stewardship
  is returning the pendulum back to biomass as the
  source for humans energy, chemical and agronomic
  needs
• Research is needed to optimize both

• Advanced pyrolysis system development for
  combined energy, chemical, and biochar production
  
• Subsequent utilization of biochar in a
  sustainable and environmentally responsible
  manner not limited solely to soil application

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American Society of Agronomy
Biochar Community
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Acknowledgements

• I would like to acknowledge the cooperation
• National Council for Air and Stream Improvement
  (NCASI)
• Universität Bonn (Germany)
• IRNASE-CSIC (Spain)
• Università di Bologna (Italy)
• Penn State University of Minnesota
• Illinois Sustainable Technology Center (ISTC)
  Univ. of Illinois
• US-EPA and other USDA-ARS locations
• Dynamotive Energy Systems
• NC Farm Center for Innovation and Sustainability
• Best Energies
• Northern Tilth
• Minnesota Biomass Exchange
• Biochar Brokers
• Chip Energy
• AECOM
• Avello Bioenergy
• ICM, Inc.
• Freedom Field Energy

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USDA-ARS Biochar and Pyrolysis Initiative
Multi-location USDA-ARS research efforts
GRACEnet Project (30 locations) Greenhouse Gas
Reduction and Carbon Enhancement Network
REAP Project (24 locations) Renewable Energy
Assessment Project
Biochar and Pyrolysis Initiative (15 locations)
Ongoing field plot trial (6 locations)