Carbon dioxide, methane and nitrous oxide emissions from an oil palm plantation on deep peat as affected by nitrogen fertilisation

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CO2, CH4 and N2O emissions from an oil palm plantation on deep peat as affected by N fertilisation

23 February 2012 – ICOPE, Bali

Kristell Hergoualc’h

Handayani E, Indrasuara, Samosir Y, van Noordwijk M, Bonneau X, Verchot L

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Climate change and greenhouse gases

Catastrophic consequences

Increase in temperatures

+ 1°C

Anthropogenic cause: GHG emissions

CO2 77%

CH4 14%

N2O 8%

F-gaz 1%

IPCC (2007)

Share GHGGHG GWP

CO2 1

CH4 25

N2O 298

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Greenhouse gases and agriculture

Global share GHG Agriculture 46% N2O: Nitrogen fertilisation

45% CH4 (livestock, rice fields)

9% CO2 (biomass combustion)

www.ferilizer.org/ifa/statistics

Atm

osph

eric

N2O

(ppb

)

N fe

rtili

zer c

onsu

mpt

ion

(mill

ion

tons

N)

Baumert et al. (2005)

IPCC (2007)

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Oil palm

World’s most rapidly

expanding crop

(Indonesia, Malaysia)

Expansion to the detriment of natural forests ÞLarge C losses (Murdiyarso et al. 2010; Hergoualc’h & Verchot 2011)

ÞBiodiversity losses (Danielsen et al. 2008) ÞBiofuel C debt (Fargione et al. 2008)

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Oil palm

Large doses of N fertiliser application:

Mineral soils: 50 – 230 kg N ha-1 y-1

Peat soils : 50 – 160 kg N ha-1 y-1

Both on mineral (89%)

& peat soils (11%) (Koh et al. 2011)

Voluntary RSPO and Government mandatory rules forbid forest conversion and use of deep peat

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Research questions and hypothesis

Þ Short term and moderated in CH4 & CO2 emissions

Þ Long term and large in N2O emissions

How does N fertilisation affect GHG emissions in an oil palm plantation on deep peat?

How does the emission factor related to N2O emissions arising from N fertilisation in an oil palm plantation on peat compare with IPCC estimates?

Þ Emission factor > IPCC estimates (recently opened peat with low N availability)

Can optimisation of N fertilisation GHG emissions per unit product?

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Location and soil characteristics

Climate

2466 mm y-1, 26.5°C

Driest months: June – Sept.

Peat properties

Fibric

Depth (8.5 m)

pH (3.6)

Corg (42%)

Norg(1.2%)

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Experimental plot

Deforested in 04, acquired by PT. Bakrie in 07 in a state of fallow

Planted Dec. 09; measurements Sep. 10

148 palms ha-1

Water table -56 cm

® N0: 0 kg N ha-1

® N1:14 kg N ha-1 (20 kg N ha-1 2010, 48 kg N ha-1 2011)

® N2: 28 kg N ha-1 (40 kg N ha-1 2010, 96 kg N ha-1 2011)

Fertiliser trial Factorial design: 3 N x 3 P x 3 K, 2 Ca (54 plots, 8 rows x 4 palms)

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“In situ” measurements

Soil and air temperatures, soil moisture, water table depth

Soil effluxes of N2O, CO2, CH4 (closed chamber method)

Sampling frequency

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Methods

Soil CO2 efflux: “in situ” IRGA

Soil N2O, CH4

4 replicate chambers per N dose

4 samples/chamber

(t0’, t10’, t20’, t30’)Transportation to the laboratory

Analysis by gas chromatography

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Extrapolation at the plot scale and emission factor

Emission factor Ef

Slope regression between N dose and GHG emissions

FZ

NFZ1.5 m

Zone Share plot N2O assigned

NFZ 92% N0

FZ 8% N1 / N2

Example

N2O N1 Plot = 8% N2O N1 + 92% N2O N0

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N2O emissions in the fertilised zone

N2ON2 > N2ON1 > N2ON0 (P < 0.0001)

-1 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29-100

0

100

200

300

400

500

600

700N0 N1 N2

Days after fertilization

N2

O (

g N

-N2

O h

a-1

d-1

)

N dose Cumulated N2O emissions(kg N-N2O ha-1 28 days)

N0 0.3 ± 0.3

N1 2.4 ± 1.1

N2 8.8 ± 1.7

Cumulated emissions

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N2O emissions at the plot scale and emission factor (Ef)

N dose Cumulated N2O emissions(kg N-N2O ha-1 28 days)

N0 0.3 ± 0.3

N1 0.5 ± 0.4

N2 1.0 ± 0.6

Cumulated emissions plot scale

Emission factor

Þ Ef = 2.5% ± 0.1%

0 5 10 15 20 25 300.0

0.2

0.4

0.6

0.8

1.0

1.2

f(x) = 0.0247546965269064 x + 0.277182511855285R² = 0.920823655059141

N dose (kg N ha-1)

Cu

mu

lati

ve

N2

O p

lot

(kg

N-N

2O

ha

-1 2

8

da

ys

)

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CH4 emissions fertilised zone & plot scale

No significant between N doses treatments (P = 0.3)

N dose Cumulated CH4 emissions FZ(kg C-CH4 ha-1 28 days)

Cumulated CH4 emissions Plot Scale(kg C-CH4 ha-1 28 days)

N0 0.2 ± 0.2 0.2 ± 0.2

N1 0.6 ± 0.5 0.2 ± 0.2

N2 0.4 ± 0.4 0.2 ± 0.2

Cumulated emissions

-1 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29-30

-10

10

30

50

70

90N0 N1 N2

Days after fertilization

CH

4 (

g C

-CH

4 h

a-1

d-1

)

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CO2 emissions fertilised zone & plot scale

CO2 N2 > CO2 N1 , CO2 N0 (P = 0.0002)

N dose Cumulated CO2 emissions FZ(Mg C-CO2 ha-1 28 days)

Cumulated CO2 emissions Plot scale(Mg C-CO2 ha-1 28 days)

N0 1.9 ± 0.5 1.9 ± 0.5

N1 2.1 ± 0.2 1.9 ± 0.5

N2 2.7 ± 0.3 1.9 ± 0.5

Cumulated emissions

-1 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29-50

50

150

250

350

450N0 N1 N2

Days after fertilization

CO

2 (

kg

C-C

O2

ha

-1 d

-1)

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Oil palms response to fertiliser application

No between N1 & N2 treatments

0 6 12 18 2420

60

100

140 N0N1N2

Months After Planting

Co

llar

gir

th (

cm

)

6 12 18 24 120

160

200

240

280 N0N1N2

Months After Planting

Fro

nd

len

gth

(c

m)

12 18 240.0

0.2

0.4

0.6

0.8N0N1N2

Months After Planting

Vig

or

ind

ex

0 6 12 18 24 100

200

300

400 N0N1N2

Months After Planting

Pa

lm H

eig

ht

(cm

)

6 12 18 24 5

15

25

35 N0N1N2

Months After Planting

Gre

en

lea

f n

um

be

r

N0 N1 N20

2

4

6

8

10Hanging female bunches palm-1 24 MAP

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Discussion

No correlation with soil and air temperatures, soil moisture, water table depth: Short period observation

Comparison with literature®No study on the effect of N fertilisation on GHG emissions

from oil palm plantation® Melling et al. (06, 05): No intensive sampling after

fertilisation, largest N2O fluxes during wet season

N2O(g N-N2O ha-1 d-1)

CH4

(g C-CH4 ha-1 d-1)CO2

(kg C-CO2 ha-1 d-1)

This study (N0) 12.2 ± 4.7 6.0 ± 2.7 71.0 ± 10.6

Melling et al. 14 1.2 53

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Discussion

Very strong effect of N fertilisation on N2O emissions:

Ef = 2.5% Peat recently opened and drained? Young age of the palms?

*Agriculture, Forestry & Other Land Use, Vol. 4, Chap. 11 (N2O emissions from managed soils, and CO2

emissions from lime and urea application)

IPPC guidelines for GHG inventories (2006)*® Ef = 1% [0.3% – 3%]

® Ef calculated as yearly N2O / N fertilisation rate

Effect N fertilisation on palm growth ® + effect N1 dose but no N1 & N2 doses also observed

on coconut palms (Bonneau et al., 93)

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Conclusions

Complementary studies on GHG for improving Ef - Experimental design improved with measurements in both

fertilised and non-fertilised zones (results under analysis)

- Yearly measurements including & fertilisation period in a 7-year old plantation

GHG emission vs. Crop response to fertiliser

® N2ON2 = 2 N2ON1

® CropN2 CropN1

Reduction of emissions per unit product feasible

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