peter slavich rice husk biochar improves productivity of sandy soils
TRANSCRIPT
Rice husk biochar improves productivity of sandy soils in
Central Coastal Vietnam
Peter Slavich, Tran Tien Dung, Brad Keen and Hoang Minh Tam
NSW Department of Primary Industries, WollongbarCentre for Coastal Agricultural Landscapes, Southern Cross UniversityAgricultural Science Institute for Southern Central Coastal Vietnam
Australian Centre for International Agricultural Research
Biochar activities in Vietnam and Aceh
• What are the effects on crop productivity and soil properties?
• How does biochar affect plant nutrient availability and water use efficiency?
-100.0
0.0
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500.0
600.0
thang 1 thang 2 thang 3 thang 4 thang 5 thang 6 thang 7 thang 8 thang 9 thang 10 thang 11 thang 12
ða Nang Qui Nhon Nha Trang Poly. (ða Nang) Poly. (Qui Nhon) Poly. (Nha Trang)
Binh Dinh
Ninh Thuan
Monthly rainfall
Peanuts intercropped with tree crops on sandy soil in Binh Dinh
Irrigation of field crops using hand held hose in Binh Dinh
Cow manure is widely used as soil amendment
Rice husk biochar From Philippines
Rice husk stoves usedin Vietnam, Phang Rang.
Phang Rang rice husk biochar from stove, biochar is doused withwater after being raked from stove- Biochar samples B and C in slide 17
Rice husk stoves are smoke free
Rice husk biocharused by local nurseries for plant propagation
Rice husk stove used in Hanoi – biochar samples D&E in slide 17, D was not doused with water to prevent further burning
Treatments
• Control (nil NPK and manure) • Manure• NPK• NPK+ manureEach with and without biochar; ie 8 treatments NPK (30 N:60 P2O5 :90 K2O); cow manure 5 t/haRice husk biochar 20 t/ha3 reps, random block design, farmer practice field trial.
Biochar trial with peanuts on sandy soil in Binh Dinh, Vietnam
2.2Saturated water content
g/g
27162717CEC cmol(+)/kg
0.120.150.110.220.076Total P %
1.10.4410.830.72Total Nitrogen %
4211463435Total Carbon (Dumas) %
8.28.17.49.1pH (CaCl2)
0.771.51.50.95EC (1:5) dS/m
EDCBA
Rice husk biochar sample
A =Philippines biochar; B &C from rice husk stoves in Phang Rang; D&E residue fromHanoi cooking stove
Above ground biomass of peanut
LSD=0.23
Biomass greater when NPK appliedBiochar increases biomass productionNo significant response to manure
0
0.5
1
1.5
2
2.5
Control NPK Manure Manure + NPK
Dry
mat
ter
bio
mas
s (M
g h
a-1)
Nil RH biochar
RH biocharLSD=0.23
Rice husk biochar on groundnut pod yield (2009)
LSD=0.3
NPK and manure increase yieldBiochar enhances pod yield response to NPK but not manurePeanut yields also increased with biochar application alone
0
0.5
1
1.5
2
2.5
Control NPK Manure Manure + NPK
po
d y
ield
(Mg
ha-1
)
Nil RH biochar
RH BiocharLSD=0.3
Potassium uptake
NPK enhances potassium uptakeBiochar enhances fertiliser potassium uptake
0
5
10
15
20
25
30
35
40
Control NPK Manure Manure + NPK
K u
pta
ke (
kg h
a-1
)
Nil RH biochar
RH biocharLSD=10.8
Phosphorous uptake
NPK enhances P uptakeBiochar enhances fertiliser P uptake
0
2
4
6
8
10
12
14
16
Control NPK Manure Manure + NPK
P u
pta
ke (
kg h
a-1
)
Nil RH biochar
RH biocharLSD=4.1
Nitrogen uptake
N uptake not enhanced by NPK or manure – legume effectBiochar enhances N uptake when manure + NPK applied
0
5
10
15
20
25
30
Control NPK Manure Manure + NPK
N u
pta
ke (
kg h
a-1
)
Nil RH biochar
RH biocharLSD=7.7
10
11
12
13
14
15
16
Nil Manure +nil NPK Nil Manure + NPK Manure +nil NPK Manure + NPK
Ave
rag
e fi
eld
wat
er c
on
ten
t m
m (
0-0.
2m)
Nil Biochar
Biochar
Field water content
LSD=2.2
Assessed in field using portable capacitance probe
Field capacity water content
Assessed in laboratory in Vietnam using field samples
0.00
0.05
0.10
0.15
0.20
0.25
Control NPK Manure Manure + NPK
Sat
ura
ted
wat
er c
on
ten
t (g
g-1
dry
so
il)
Nil RH biochar
RH biocharLSD=0.04
Increase in soil water holding capacity
Pilot laboratory assessment conducted in NSW
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0 20 30 40 60 80
Application rate (Mg ha-1 mixed to 20cm depth)
satu
rate
d w
ater
co
nte
nt
(g g
-1 )
20
22
24
26
28
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80
Soil organic matter % (0-0.2 m)
So
il m
ois
ture
aft
er i
rrig
atio
n m
m (
0-0.
3 m
)
Nil Biochar
BiocharC
NPK M
NPK+M
C
M
NPK NPK+M
C – control, NPK- fertiliser, M - manure
Field capacity water content vs soil organic matter
Field water content higher due to organic matter accumulation which is enhanced in biochar treatments
Conclusions
• Rice husk biochar has – improved uptake of P and K from sandy soils
– increased water holding capacity– Increased yields of peanuts
• Trials are continuing