Transcript Evaluation of Designer Biochars to Ameliorate Select

Designing biochar types to modify selective
soil properties
Jeff Novak, USDA-ARS-CPRC
Northeast Biochar Symposium
November 13, 2009
Isabel Lima (ARS-NO)-preparation and characterization of biochar
Warren Busscher (ARS-Florence)-soil hydraulics
Harry Schomberg (ARS-Watkinsville)-soil N transformations
Christoph Steiner (UGA)-preparation and characterization of biochar
Julia Gaskin (UGA)-preparation of biochar and MBC
KC Das (UGA)-preparation of biochar and properties
Mohamed Ahmenda (NC A&T)-preparation of biochar
Djaafar Rehrah (NC A&T)-preparation of biochar and characterization
SunYoung Bae (NC A&T)-biochar hydrophilic/hydrophobic properties
Baoshan Xing (UM-A)-13C NMR & IR characterization of biochar
Thomas Ducey (ARS-Florence)-soil microbial population dynamics
Jim Reeves (ARS-Beltsville)-NIR characterization of biochar and soils
Don Watts (ARS-Florence)-experimental set up and measurements
John Loughrin (ARS-Bowling Green)-biochar sorption of pollutants
USDA United States
Department of
Agriculture
USDA-ARS
GRACEnet
program
Physiography of SE USA Coastal Plain
In the SE Coastal
Plain, most of the
agricultural soils
formed in fluvial and
marine sediments
deposited 0.5 to 5
million yrs ago.
The soils are sandy
with poor fertility,
acidic pH values, and
low soil organic
carbon contents
(SOC).
Piedmont
Coastal Plain
19.1 million acres in SC and about 12.8 million of total
land area is in the Coastal Plain (Pam Thomas, SC NRCS)
Soil association across a SC Coastal
Plain landscape
%SOC in Paired Field soil profiles (2002)
0
Norfolk
-5
Bonneau
Paired Field at PDREC, Florence SC
soil depth (inch)
Coxville
-10
-15
-20
Bonneau (Ex. well drained)
Norfolk (well drained)
Coxville (poorly drained)
-25
Deep coring at Paired Field
-30
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
%Soil organic carbon (SOC)
Sandy soils used for agriculture have low
to very low %SOC contents with profile
depth.
How can we increase their potential to
sequester more OC in the profile?
Rebuilding SOC using tillage and
crop management practices
Tillage management effects (24 y) on SOC
in the Norfolk soil profile (Novak et al., 2007).
0
-20
depth (cm)
error bar = 1 SD
-40
-60
-80
conservation
conventional
-100
0
2
4
6
8
10
12
14
16
18
20
SOC (g kg-1)
In a 6 year corn + cotton
rotation, about 15 Mg OC/ha
were returned to sandy soils
(Novak et al., 2009).
Conservation tillage effect to sequester
C was depth dependent.
The SOC increased by only
0.51% at 0-3 cm depth
(< 4% of total residue OC).
Agents to sequester soil OC and
lower CO2
• Conservation tillage (low results)
• C uptake by vegetation (forests)
• C feedstock for biochar, biofuel, syngas manufacture (new)
Conservation tillage
Biochar from pine
What is biochar?
Biochar is a charcoal-like product
manufactured in ovens under
low/high temperatures, pressures
and moisture.
It can be made from various
organic feedstock’s (plants,
manure, byproducts, etc.).
Biochar oven at NC A&T
Feedstock is subject to pyrolysis
(under N2) using fast or slow
conditions.
Biochar oven at UGA
Advantages of C capture as biochar
•
•
•
•
•
Liming agent
Nutrient source
Binds Al
Energy source
Increases SOC
contents
• Improves soil
WHC
• Lasts for
millennia?
Pecan shells
Gin trash biochar
Pecan biochar in soil
Early study (2008)
13C
NMR spectra
of pecan biochar
• Incubated a high T (700º
C) pecan-shell biochar
(BC) in a Norfolk for 67 d.
● High aromatic character
(58%), high OC content
(88%), and low amount of
functional groups.
● Biochar (0, 0.5, 1 and 2%)
was mixed into soil and
then leached 2X with di.
H2O.
● Measured soil chemical
and leachate
characteristics.
% SOC contents
Soil + BC (%)
0
0.5
1.0
2.0
0 days
1.70
1.81
2.22
3.12
Novak et al., Soil Sci. 2009
60 days
1.74
1.83
2.19
2.92
Designer biochar incubation in soil (2009)
• Biochar chemical production process and feedstock choice
can be planned to create designer biochar that has specific
chemical characteristics allowing for more C sequestration and
improvement of selective chemical and/or physical issues of
sandy Coastal Plain soils.
Designer
biochar
Soil
Incubation
for up to 128 d.
Designer
biochar in
soil (2%)
Switchgrass feedstock
Pyrolyzer
Table 1. Biochar recoveries, volatile matter, pH,
and surface area measurements (Novak et al., in review)
Feedstock
Pyrolysis
(ºC)
C recovered
(%)
Volatile
Matter (%)
pH
Surface
area (m2 g-1)
Peanut hull
400
59
38.4
7.9
0.52
500
35
18.1
8.6
1.22
350
50
61.6
5.9
1.01
700
30
9.7
7.2
222
350
72
36.7
8.7
1.10
700
44
14.1
10.3
9.00
250
89
74.4
5.4
0.40
500
51
13.4
8.0
62.2
Flash
----
----
5.7
1.28
Pecan shell
Poultry litter
Switchgrass
CQuest
Table 2. Biochar ash content and elemental
composition (%, oven-dry, wt. basis) (Novak et al., in review)
Feedstock
ºC
ash
C
H
O
N
S
Na
P
Peanut hull
400
8.2
74.8
4.5
9.7
2.7
0.09
< 0.1
0.26
500
9.3
81.8
2.9
3.3
2.7
0.10
< 0.1
0.26
350
2.4
64.5
5.3
27.6
0.26
0.01
0.01
0.03
700
5.2
91.2
1.5
1.6
0.51
0.01
0.02
0.05
350
35.9
46.1
3.7
8.6
4.9
0.78
1.88
2.94
700
52.4
44
0.3
< 0.1
2.8
1.0
2.69
4.28
250
2.6
55.3
6.0
35.6
0.43
0.05
< 0.1
0.1
500
7.8
84.4
2.4
4.3
1.07
0.06
0.1
0.24
Flash
8.6
71.4
3.4
16.3
0.3
0.02
----
----
Pecan shell
Poultry litter
Switchgrass
CQuest
Table 3. Mean pH and Mehlich 1 extractable P and Na
concentrations in a Norfolk loamy sand at 0 and 128 d† of
incubation with different biochar-types (Novak et al, in review).
Soil + biochar
Pyrolysis (Cº)
Incubation (d)
pH
P (lb/a)
Na (lb/a)
Soil alone
----
0
5.9
65
8
----
128
5.6
63
6
350
0
8.0
1107
706
128
8.4
905
64
0
9.7
1593
995
128
9.0
1658
547
0
6.2
57
10
128
6.6
51
7
Poultry litter
Poultry litter
CQuest
700
Flash
†Soil treatments were leached 4X with di. H O between 0 and 128 d of incubation.
2
Moisture contents (w w-1) of Norfolk loamy sand
after biochar additions and leaching with di. water
40
B. High temp biochars
A. Low temp biochars
%soil moisture content (w/w)
%soil moisture content (w/w)
40
Control
Switchgrass
Pecan shell
Poultry litter
Peanut hull
30
20
10
0
Control
Switchgrass
Pecan shell
Poultry litter
Peanut hull
CQuest
30
20
10
0
0
2
4
6
days
8
10
12
0
2
4
6
days
8
10
12
Table 4. Mean % soil moisture contents† in a Norfolk loamy sand
treated with different biochar types (n = 4).
% Soil moisture (w w-1) on day:
Soil + biochar
Pyrolysis (Cº)
0
2‡
6
Soil alone
----
2.9
19.5a
9.6a
Poultry litter
350
4.6
21.1a
12.5b
700
4.3
20.1a
10.4a
250
3.4
24.5b
14.3b
500
4.4
29.9b
19.9b
Flash
4.1
24.0b
14.1b
Switchgrass
CQuest
†Soil treatments leached with 1.2 PV of di. H O and leachate collected for 30 h. ‡Tested using a
2
multiple comparison test vs. control (Holm-Sidek method).
Conclusions:
• Higher pyrolysis
temperatures resulted in
lower biochar recoveries,
greater surface area, pH,
and ash contents.
• Biochars produced at
higher pyrolysis
temperatures increased soil
pH, influenced N availability,
and poultry litter biochar
grossly increased Mehlich 1
[Na] and [P].
• Water holding capacity
varied after biochar
incorporation.
• Biochars can be designed
to have specific qualities
that can target distinct
properties in soils.