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LAND-APPLICATION OF BIOCHAR IN AGROFORESTRY

Vimala Nair, PK Ramachandran Nair, Nilovna Chatterjee Biswanath Dari, and Andressa Freitas

University of Florida

3rd European Agroforestry Conference

Montpellier SupAgro, France23 – 25 May 2016

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Biochar

• Created by thermal decomposition of biomass with little or no oxygen

• Varying temperatures from 300ºC to > 700ºC

• Created by thermal decomposition of biomass with little or no oxygen (pyrolysis or gasification)

• Intended as a soil amendment and a means of storing n

http://www.airterra.ca/biochar-what-is-biochar

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Biochar Production

http://eep-ces.com/technology/pyrolysis/

Serbia

Roussel Kiln, Nevada, USA

http://www.re-char.com/2012/06/11/providing-

organic-sustainable-alternatives/

http://www.biochar-international.org/carbongold

Kenya Brazil

http://www.slideshare.net/saibhaskar/biochar-production-and-uses-dr-

reddy-5242206

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Sources of Biochar

Corn stover

Cow manure

Wood chip

Poultry manure

Bagasse

Agricultural and forestry by-products

Industrial by-products

Animal wastes

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Properties of Biochar

Biochar feedstock

Mehlich 3-P Mehlich 3-Ca Mehlich 3-Mg

Hardwood 480 670 290

Poultry litter 14550 16000 5520

Biosolids 7060 2330 5140

Pure maple 100 4810 670

Pure pine 70 490 50

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Uses of Biochar

• Sequesters carbon in the soil

• Improves soil productivity (fertilizer source), especially on poor soils

• Improves water retention / reduces water demand

• Improves water quality / less downstream pollution

• Reduces emissions of greenhouse gases from the soil

• Increases microbial activity

• Serves as a bio-fuel/by-product and a renewable means of

sustaining further biochar production

Biochar amendment to improve soil properties and sequester carbon

Source: Lewis Peake

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Biochar Research

Research Locations

• Europe, Australia, Belgium, Brazil, Canada, Chile, China, Colombia, Costa Rica, Germany, Guyana, India, Italy, Japan, Malaysia, Netherlands, New Zealand, Saudi Arabia, South Korea, Thailand, United Kingdom, United States

European Biochar Projects

http://cost.european-biochar.org/en/projects

http://www.biochar-

international.org/research/education

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Publications on Biochar (2005 – 2012 )

• Bars indicate numbers of publications

• Black bars represent non-soil-related biochar publications

• Green bars represent soil-related biochar publications.

• The red data and line (read on the secondary y-axis) represent the biochar publications (‘biochar’ and ‘soil’ in the topic) as a proportion of crop residue publications (‘crop residue’ and ‘soil’ in the topic).

European Journal of Soil Science, January 2014, 65, 22–27

(Guest Editor’s Introduction)

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Biochar additions and P releaseLow P retentive soil High P retentive soil

HWB

PLB

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Biochar additions to P-impacted Soils

0

1

2

3

4

5

P in s

olu

tion (

mg L

-1)

Initial P added (mg kg-1)

Soil + 2% HWB Soil

0

40

80

120

160

P in s

olu

tion (

mg L

-1)

Initial P added (mg kg-1)

Soil + 2% HWB Soil

Hardwood biochar (HWB) addition at 2% rate to: (i) a P-retentive soil in coffee plantation, Kopa,

India with previous inorganic P addition and (ii) a less P-retentive soil in Florida, USA with

previous manure-P loading (Note differences in values for P in solution on the y-axes).

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Application of Biochar to AFS: Soils

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Research Areas Pertinent to AF

• P retention and loss for a given soil from manure (poultry, dairy, swine, etc.) or wood debris vs. their respective biochars.

• What are the benefits of adding biochar vs. their respective feedstock source?

• P retention and loss from biosolids (sewage sludge) vs. biochar from biosolids feedstock (important fertilizer source in Europe).

• Consider mixed feedstock sources available at different farms that would supply sufficient P for crop uptake.

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Biosolids and Biosolids Biochar

Biochar made from biosolids through the process of pyrolysis at 400 °C

Mehlich 3-P decreased from 10,960 mg kg-1 in biosolids to 7,050 mg kg-1 in biosolids biochar

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Biosolids and Biosolids Biochar Properties

P K Ca Mg Zn Mn Cu Fe Al Ni Na

Biosolids 10960 2216 4730 6271 58 31 6.8 573 258 0 379

Biosolids biochar 7062 502 2326 5139 59 21 20 437 188 0 87

Pyrolysis involves the loss of

thermally unstable components

Calcite: Calcium carbonate

Kaolinite: Clay mineral

Quartz: Silica

Mehlich 3 - extractable

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P Release with Sequential Extractions

• Non-incubated: Biochar or biosolids biochar without P addition

• Incubated: Biochar or biosolids biochar incubated with 100 mg L-1 P

0

10

20

30

40

50

60

70

80

90

0 1 2 3 4 5 6 7 8 9 10

P in

so

luti

on

, mg

L-1

Extraction number

Biosolids Biochar non-incubated

Biosolids biochar incubated

Biosolids non-incubated

Biosolids incubated

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Conclusions

• Biochar feedstock selection

– Availability at AF farm

– Mixed feedstock to control P release

• Best management practices for the application of a given type of biochar

– Need to be based on site-specific assessments

• Soil characteristics (high P-fixation vs. sandy soils)

• P loading history

• Maintaining moisture content at field capacity for a high P-retentive soil to assist in releasing P

– Consider necessity for repeated applications of biochar

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http://www.sanniesshop.com/bio-char.html

Thank you!

https://www.agronomy.org/publications/csa/articles/58/9/4