Development of Biochar Based Fertilisers

Dr S Joseph, Dr S McGlashan,

Dr P Munroe, Dr Y Lin, C Chia

Introduction

A Research and Development Program has been

undertaken to develop a biochar based fertiliser;

•Be applied at low application rates (<1 tonne/hectare)

•Provide yields similar to chemical fertilisers applied at similar application

rates using existing application equipment

•Formulation is easily modified for specific soils and plants

•Increases water holding capacity , nutrient uptake efficiency, CEC,

adsorption of toxic elements, mineralisation of soil organic matter and

beneficial micro-organisms.

•Has a recalcitrant component (biochar, minerals and clay) and a labile

organic component (torrefied manure and organic molecules on biochar.

The labile component provides food for soil micro-organisms and act as

signaling chemicals to assist in nutrient uptake and plant health

Terra Preta and Bocashi

(Biochar Mineral Complexes)

Terra Preta and Bocashi soils are composed of a mixture of biochar that has reacted with

clay, minerals and biomass in the presence of micro-organisms to produce organo-mineral

agglomerates. These soils are rich in elements such as P, Mg, Zn, Ca, Fe, Mg, Ti and Mn.

They exhibit higher water holding capacity than the surrounding soil, higher pH, and higher

cation exchange capacity (CEC).

What is BMC?

Materials1) Biochar made at low temperatures <550C) preferably from woody waste

or purpose grown trees with or without activation

2) Clay (preferably a swelling clay that has a high content of smectite and

organic matter)

3) High mineral ash biomass such as bagasse palm waste, manures, bark,

clean paper sludge, rice husks, bones, compost

4) Minerals such as calcium carbonate, rock phosphate, dolomite, crushed

granite and basalt

5) Ash from biomass burning in furnaces.

Process1) Mix wet biomass and minerals with or without biochar

2) Place material into the torrefaction kiln and heat up to 180C to 250C.

Hold this temperature for 1 to 5 hours.

3) Add more biochar and other growth enhancing compounds or

inoculate with microbes. Further activation can be carried out.

4) Can either granulate, pelletise or prill or bag loose material

Characterisation of BMC

BMC consists of a wide range of particles that have

different morphologies and different compositions.

Some of the particle (chemically activated biochar) have

a high surface area, high cation exchange capacity, high

aromaticity, and high concentration of functional groups.

Other particles have a high labile carbon content and

high concentration of soluble minerals but a lower

surface area.

BMC can be designed as a slow release fertiliser, and/or

as a catalyst to stimulate microbial growth. It appears

that BMC may provide nutrients on demand through their

redox and electrical properties

Some Agronomic Properties of BMC

EC .01-3.6 Ds/m

pH (CaCl2) 5.7-8.0

Total P 1-7 %

Colwell P 1800- 3700 mg/kg

Total Nitrogen 1.0-6 %

Total Carbon 20-40 %

Total K .1-5 %

KCl extractable

Ammonium100-500 mg/kg

KCl extractable Nitrate .2-1 mg/kg

Organic Carbon 10-50 %

ANC 7.0-10.0 % CaCO3 equiv.

Total Exchangeable

Cations50-110 cmol(+)/kg

Ti+Fe+Mg+Mn+Ca 1-5 %

The product is formulated for particular soils and crops

Structure of BMC

Biochar surrounded by minerals and torrefied manure

Structure of BMC

Distribution of Minerals on Outside of Biochar

Structure of BMC (TEM Examination

Distribution of Minerals Inside Coating

Structure of BMC

Distribution of Surface Functional Groups

XPS SURFACE BMC6 BMC5

Name Name At. % At. %

C1s A C-C/C-H 26.34 10.68

C1s B C-O 6.43 13.77

C1s C C=O 1.42 4.04

C1s D COOH 2.41 2.14

N1s B N-C 0.98 0.28

N1s A Amino acid N 1.55 1.02

N1s C NH3 0.66

O1s A Silicates 38.64 27.17

O1s B O-C 0.38 17.54

Biochar Heat Treatment Temp (HTT)= 600C

HTT = 400C

Biopolymers – proteins and polysaccharides; Building blocks – oxidat.

products of humics; �Neutrals - alcohols, aldehydes, ketones, mono-

oligosacchrides; Acids- monooprotonic organic acids < 360 Daltons

GC-MC Solvent Extracted Labile C conc. mg/g charCarboxylic acids Low Temp Biochar High Temp Biochar

Hexadecanoic acid 788 84

Heptadecanoic acid, methyl ester 3

cis-cis-9,12-Octadecadienoic acid 6

cis-9-Octadecenoic acid 44 5

trans-9-Octadecenoic acid 24 7

Octadecanoic acid 171 77

LC-OCD Water Extracted Labile C conc. mg/g charDissolved Organic C 204 77

% Hydrophobic 0.0% 56.0%

% Biopolymers 8.5% 7.6%

% Humics 28.1% 15.1%

% Building Blocks 14.4% 20.5%

% Low molecular weight neutrals 46.0% 0.0%

% Low molecular weight acids 2.6% 7.0%

Sandy Soil Control

1% Eucalyptus Sawdust

Biochar pyrolysed at

550C

1% BMC6;

(refe

ren

ced to

H2

Ele

ctro

de

)

1% Jarrah Biochar

BMC6 is made from;

Jarrah Biochar (pyrolysed

600C) mixed with clay,

chicken litter, minerals and

baked for 3 hrs at 220C

Activation process

anodic current generated

Change in Surface Area, Lattice structure and

Functional Groups with possibility of CO2

Capacitator

Increase in Cathodic Behavior

Testing of Biochar and BMC in Costa

Rica; Dramatic Improvement in Yields(Assess the Feasibility of Biochar Utilization in the Osa Peninsula – Feb 2010)

Commercial WA Broad-Acre Wheat Trials

# Treatment Vigour

(1-10)

Yield

(t/Ha)

Protein

(%)

Hectolitre Screenings

(%)

1.1 NPK Crop Plus 4.0 1.607 10.40 77.413 2.973

1.2 NPK Crop Plus + urea 5.3 1.457 10.50 77.110 3.780

2.1 NPK Crop B 5.0 1.467 10.87 78.693 2.497

2.2 NPK Crop B + urea 5.7 1.580 10.80 77.677 4.263

3.1 Macro Pro Extra (NPK) 5.3 1.777 10.23 80.020 2.633

3.2 Macro Pro Extra + urea 6.0 1.715 10.73 78.413 3.023

4 Nil 3.7 1.307 10.20 78.907 2.247

NPK (6:7: 3.5) Crop B applied at 25kg/Ha of BMC and 75kg/Ha of WMF;

NPK Crop Plus (8:9:4.5) 100kg/ha WMF

Macro Pro Extra (10%N; 11%P: 11%K) at 100kg/ha

Urea (46% N) at 10.5 units/ha

Increased Protein Yield although lower yield than soluble chemical fertiliser (Macro Pro)

Increased Protein Yield although lower yield than soluble chemical fertiliser

Increased efficiency of added N as Urea

Similar total biomass and colour (vigour) to soluble fertiliser

DAFWA 2009 SORGHUM PLOT TRIALS

0

20

40

60

80

100

120

140

Control Solube 60kg/ha BMC 300kg/ha

gm

so

fdry

gra

in/b

in

Treatment

IMPROVEMENT IN FUNGI GROWTH

S = Water soluble fertiliserSOURCE

DR Z Suliman

University of Western Australia

0%

10%

20%

30%

40%

50%

60%

70%

80%

Nil Solube 60kg/ha BMC 300kg/ha

Pe

rce

nta

ge

Colo

nis

atio

n

Treatments

IMPROVEMENT IN FUNGI GROWTH

P

K

CaC O

Al Si

Fe

2010 Victorian commercial trials

Treatment Yield (T/ha)

BMC 7

Nil 1.16 – 2.02

0.3 T/ha BMC 2.85

1.0 T/ha BMC 1.22

3.0 T/ha BMC 2.36

10 T/ha BMC 3.48

100 kg Diammonium P/ha 1.23

Note – replications underway. Considerable variation between the Nil plots.

Pasture Trials Mixed Oats and Rye

NSW DPI 2009 Wheat Pot Trial Results

0

0.5

1

1.5

2

2.5

0 2 4 6 8 10 12

Average gms/pot without N

Ave

. to

tal g

ms o

f b

iom

ass

(pla

nt)

/po

t

Tonnes/hectare of BMC

Lsd=0.29

Significant result above 2.5 tonnes/hectare of BMC or about .8 tonnes/hectare of biochar.

Final results are total grams per pot (see height data for plant numbers but the target was 8

plants per pot, thinned from a sowing of 10). Dry weight percentage is simply dry weight

over wet weight X100. Plants were dried at 80deg in our agronomy shed for 5 days.

Adding N as Urea. Urea=46% N. Each pot = 250g ODE. with 0.055g Urea/pot

0

0.5

1

1.5

2

2.5

0 1 2 3 4

Average gms/pot without N

Average gms/pot with N

Tonnes/hectare of Biochar in BMC

Small scale/portable systems

Development of a small portable

biochar unit

With an output of 100-150kg/hr of

biochar

Chipper incorporated into the design

High efficiency low emissions porous

burner

Option to Capture up to 2MWs of

Heat

Options to oxidise surfaces and add

nutrients

Small scale/portable systems600 kg/hr Torrefier

Pyrolysis and Torrefaction Unit

Anthroterra has designed a 1 tonne/hr pyrolysis kiln and a 2 tonne/hr

baking kiln to make BMC. These units are scalable to 4 tonnes/hr

Pyrolyser with thermal output to run either

1)boiler/turbine, stirling or organic rankine cycle genset

2)Thermal process equipment

Baking Oven to make

Biochar Mineral complex

Biofilter

In summary

Biochar Mineral Complexes appear to stimulate beneficial

microbial growth and improve nutrient uptake efficiency at

low application rates of biochar

Surfaces have high concentration of acidic and basic

functional groups and a relatively high humic acid content

that results in high CEC

Labile polar and non polar organic molecules appear to

stimulate microbial growth and could act as signalling

compounds

Surfaces are redox active and could increase the

breakdown of biomass to SOM

Properties are easy to adjust for Soil and crop