MARCO/GRA Joint Workshop on Paddy Field Management and Greenhouse Gases September 1 3 2010 Tsukuba Japan

Possible options to mitigateSeptember 1-3, 2010 Tsukuba, Japan

Possible options to mitigate greenhouse gas emissions g g

from paddy fields

Ka ki In b shiKazuyuki InubushiGraduate School of Horticulture, Chiba University,

1Matsudo, Chiba, 277-0942 Japan

Figure TS.6. (Top) Patterns of linear global temperature trends over the period 1979 to 2005 estimated at the surface (left), and for the troposphere from satellite records (right). Grey indicates areas with incomplete data. (Bottom) Annual global mean temperatures (black dots) with linear fits to the data. The left hand axis shows temperature anomalies relative to the 1961 to 1990

average and the right hand axis shows estimated actual temperatures, both in °C. Linear trends are shown for the last 25 (yellow), 50 (orange), 100 (magenta) and 150 years (red). The smooth blue curve shows decadal variations (see Appendix 3.A), with the decadal 90% error range shown as a pale blue band about that line. The total temperature increase from the period 1850 to 1899

to the period 2001 to 2005 is 0.76°C ± 0.19°C. {FAQ 3.1, Figure 1.}

Figure TS.28. Projected surface temperature changes for the early and late 21st century relative to the period 1980 to 1999. The central and right panels show the AOGCM multi-model average projections (°C) for the B1 (top), A1B (middle) and A2 (bottom) SRES scenarios averaged over the decades 2020 to 2029 (centre) and 2090 to 2099 (right). The left panel shows corresponding

uncertainties as the relative probabilities of estimated global average warming from several different AOGCM and EMIC studies for the same periods. Some studies present results only for a subset

3

of the SRES scenarios, or for various model versions. Therefore the difference in the number of curves, shown in the left-hand panels, is due only to differences in the availability of results. {Adapted from Figures 10.8 and 10.28}

Ch i G h G (GHG ) f

INTRODUCTION

Changes in Greenhouse Gases (GHGs) from Ice-Core and Modern Data (IPCC 2007)

CO2 CH4 N2O

4

GWP

CO2= 1CO2 1CH4= 21N2O=310

in 100yrHorizon

5

Soil-Greenhouse Gases Interaction

Greenhouse GasesSun

Forest

Organic matter

6

INTRODUCTION

Trace gases as greenhouse effect

Underground water4.7%

Other anthropogenic activities7 5%

Industry8 0% OBiomass burning

Methane： 535x106 ton C/Year Nitrous oxide： 16x106 ton N/Year

%Wetland21.5%

TermiteBiomass burning

7.5%

Rumens4.7%

8.0% Ocean18.5%

Biomass burning3.1%

Slurry13.0%

Natural gas

3.7%

Ocean1.9%

Others2.8%

Paddy Field11 2%

g

7.5%Natural processes

18.5%

U l dNatural gas7.5%

I t l di ti

Oil2.8%

Industry5.6%

11.2%

Grasslands6 2%

Savanna6.2%

Forest

Upland20.4%

Sources of CH and N O (IPCC 1996)

Internal digestion15.9% Coal

2.8%

6.2% 6.2%

7

Sources of CH4 and N2O (IPCC 1996)

Mi i i i i i lMitigation options in agriculture （Mosier et al., 1998）

0.40 Pg CO2-C eq/yr0. 0 g CO2 C eq/yAbout 6% of CO2 emission from fossil fuels

水田

畜産廃棄物

PaddyLivestock i

水田Paddy物

バイオマス燃

焼

5022

25Biomass burning

waist削減ポ

テンシャル

30

63

ReductionOptions

反すう

焼

90

Ruminant animals 畜産廃

反すう動物

61

1617

63

Ruminant animals

反すう動物

Ruminant animals

バイオマス燃焼

畜産廃棄物

16Livestock waist

Biomass burning

8Total： 187 Tg/yr Total： 124 Tg/yr

GHG Inventories in Selected Asian Countries2% 15%4%

Energy

Japan (2004) Korea (1990) China (1994)Industrial

Processes1,355 MtCO2 289 MtCO2 4,058 MtCO2

Processes

Agriculture28%26% 35%

Waste

g28%26% 35%

Waste

9Indonesia (1994)

323 MtCO2

India (1994)1,214 MtCO2

Thailand (1994)224 MtCO2 Data source:

a UNFCCC Report

Paddy fields in the world 150 000 000 ha

Paddy field in the world Paddy soil serve nearly

Paddy field in Asia

y yhalf world population

Paddy field in Asia

Paddy field in Japan

I fArable

Paddy

• Important energy source for Asian peopleY d il i i i

10

Paddy• Yet no detail investigation re: impact on global environment

World Rice Area and Productionha

)

160

180

900P d ti ( illi t )

a (m

illio

n

120

140Rest of World

Rest of Asia

M

Production (million ton)

(projection)

sted

are

a

80

100Myanmar

Vietnum

Indonesia

Thailand

ce h

arve

s

40

60

Thailand

Bangladesh

China

India

Ric

0

20

0

1936

1951

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2020

Data source: IRRI Statistics11

ata sou ce: Stat st csAbout 90% rice produced in Asia

EFFECT OF LAND-USE MANAGEMENT ON GREENHOUSE GAS EMISSIONS FROM TROPICAL PEATLAMDS

S kP l b Sarawak(Talau, Mukah)

Palembayan, West Sumatra

South Kalimantan(Banjarmasin)

Jambi, Sumatra

West Java (Bogor)

South Sulawesi(Makassar)

West Java (Bogor)

12Research sites

Land-use changes in Jambi province, Indonesia

13Left: Soil types, Right: Land-use in 1999 (Tayler et al., Wetlands, 2006)

Effect of land-use change and season on GHGsfrom tropical peatlands

CO CH N OCO2 CH4 N2ODry seasonDry season Dry seasonDry season

South Kalimantan, IndonesiaInubushi et al Chemosphere 52 (2003) 603–608

14

Inubushi et al., Chemosphere 52 (2003) 603–608

Effect of groundwater level on GHGｓfrom tropical peatlands

CO CH N OCO2 CH4 N2O

Jambi, Sumatra, IndonesiaFurukawa, Y. et al., Nutrient Cycling in Agroecosystems, 71, 81-91 (2005)

15

Effect of soil pH on CH4Effect of soil pH on CH4

Tropical peat

T i l d t t t il16

Tropical and temperate peat soilsInubushi, K. et al., Nutrient Cycling in Agroecosystems, 71, 93-99 (2005)

installing underground draining pipes MoreCH4 emission

LessCH4 emission

Changes in plowed layerChanges in plowed layerLower organic substrates of CH4Lower soil moisture and

Oxidation of Fe2+ to Fe3+

Plowed layer

0.8

m

(in the fallow season)

Changes in subsoil layerL d t l l

Subsoil layer

Gleysoil

layer0.

6-0 Lower groundwater level

Lower gley soil layerEnhanced soil permeability

Gley soil

Drainage pipes: Valves were open during the mid-summer drainage, and from the final

pre harvest drainage tolayer pre-harvest drainage to submergence (in spring) except for snowy season.

Figure 1 Changes in soil profile by installation of

ND-field D-field

17

Figure 1 Changes in soil profile by installation of subsurface drainage system in a poorly-drained paddy field, and which affected major factors controlling CH4 emission.

installing underground draining pipes

18

Effect of snow cover on methane

19

Th ti l b k dTheoretical backgroundSequences of biochemical reduction-reactions

Surface water

Paddy soilPaddy soil

20

Relation between CH4 and FeRelation between CH4 and Fe

21Inubushi et al., ICSS Kyoto 1990

Relationship between Methane production and Free Fep p

250

200

/kg d.s）

メタン生成活性と遊離鉄との相関を調べたところ、遊離鉄含量が増すほど、メタン生成活性を抑制する傾向にあった。The more free-Fe, the less methane

production150

ion（

mg‐C/ Indonesia ▲ n=5

Philippines ■ n=3Thailand  ● n=6Vietnam ◆ n=6

production

y = ‐2.0103x + 43.111R² = 0.0852

y = 27.936x‐1.08R² = 0.267

100

ne produ

cti

50

Metha

n

（n=20）

0

0 5 10 15 20 25 30

F F （ /k d ）

22

Free Fe（g/kg d.s）

Effect of iron materials on methane emission from paddy soils

Furukawa and Inubushi, Nutrient Cycling in Agroecosystems, 64, 193-201 (2002)

23

Low Fe soil

High Fe soilg

24

Global Environment Research Fund S2-3a (2003-2007) CH4 & N2O シンク・ソースCH4 & N2O シンク・ソース

Test sites and mitigation technologiesPaddy ddPaddy（OM manag.） Paddy, OM management：CH4

Yamagata，Yi Xing (China)，Khon Kaen (Thailand)

Paddy（Water manag）

Upland, grassland, greenhouse

Paddy, water management：CH4Fukushima，Niigata，

Maros (Indonesia)

Upland, grassland, greenhouse：N2OKonsen Tsukuba Taketoyo KumamotoKonsen，Tsukuba，Taketoyo，Kumamoto

Shenyang (China)，Indonesia

25Quantitative on site evaluation of mitigation technology

Methane production, emission and oxidation

CH4Atmosp. C 4

20μｍ20μｍ

CO2

MethanotrophsO2 CO2

Water

（Microscopic）Water Manag

Soil

WaterMehtane oxidation

Root exudatesOld roots

Manag.OM

managOM

Mi bi l

manag.

26Dissolved CH4Methane

production

Microbialbiomass DOC or CO2

Substrates

Objectives1. Affectivity of water management y g

in reducing the contribution of paddy field to global warming

2. CH4- and N2O-related microbial activities as influence by water management

27

Irrigated area

Sep

HybridDecMar

LocalApr ‘04

Sep

Hybrid

Locall i

Nursery. plough

DecSep

HarvestAprNursery.

plough 2nd transplantingHarvest

Transplanting

Nursery. plough 2nd t l ti

Harvest

1st transplanting

さまざまな品種・栽培方法土壌 気象条件

28

plough

1st transplanting2nd transplanting土壌・気象条件

施肥管理・水管理

Treatments:Treatments:Continuously Flooded（CF）

Intermittent Drained（ID)

Continuously flooded

)

Gas samples were taken in hl b d i

Intermittent drainage

monthly bases except during intermittent drainage when the

samples were taken at 0・2・5・14samples were taken at 0 2 5 14 days after drainage

Soil samples were taken twice CH4 , CO2 and N2O

pcorresponding to land preparation

and 14 days after drainage li i

Physicochemical properties CH -trophsapplication properties, CH4-trophs, and CH4-gens

29

Results and DiscussionIrrigated Paddy Fields

60 10CF water levelID water level

600

40

-2h-1

)

8

ID water level

CF fluxID Flux

500

2h-1

)

CF

ID

20

x (m

g C

m

6

leve

l (cm

)

300

400 04.03.10 04.03.12 04.03.15 04.03.24

ux (m

g C

m-2

20

004.03.10 04.03.12 04.03.15 04.03.24

etha

ne fl

ux

2

4

Wat

er l

200

n di

oxid

e flu

-40

-20

Me

0

2

0

100

Car

bon

Greenhouse gas dynamics were controlled by water management; CH4 uptake (negative flux) was maximum when CO2 evolution was

Date (year/month/day) Date (year/month/day)

30

CH4 uptake (negative flux) was maximum when CO2 evolution was maximum, i.e., 3 days of drainage

Khon Kaen, Thailand

• Biggest city in North-east gg yThailand

• Examined field near by• Examined field near by city

• Cow-manure is utilized

Di t dli i t• Direct seedling in wet season vs traditional transplanting）

• Salt accumulation in dry season

31

season

Methane flux measurements inMethane flux measurements in paddy fields in Khon Kaen, Thailandp y ,

32

Plots arrangements

F1 F2 F3F4 F5 F6

Transplanting riceEarth

Irrigati

Direct-wet seeding rice

h road

ion canal

F5 F1 F4 F6 F3 F2

l

F1 :Basal ; 16-16-8 and Top ; 0; p ;

F2 ：Basal ; 16-16-8 and Top ; Ammonium sulfate

F3 ：Basal ; 16-16-8 and Top ; Urea; p ;

F4 ：Basal ; Organic fertilizer and Top ; 0

F5 ：Basal ; Organic fertilizer and Top ; Ammonium sulfate

33F6 ：Basal ; Organic fertilizer and Top ; Urea

Methane emission6)4

5

m-2 h

-1 ) T-O : Transplanting - Organic fertilizer

T-Ｃ : Transplanting - Chemical fertilizer (16-16-8) B-O : Broadcasting - Organic fertilizer B-C : Broadcasting - Chemical fertilizer (16-16-8)

3

4ux (mg

C

1

2

Meth

ane fl

0

T-O T-C B-O B-C

M

・Direct seeding > Transplanting→more plants inside flux chamber

・Chemical fertilizer ≧organic manure; unexpected

→ Better plant growth by chemical fertilizer, well composted manure ？

Greenhouse gas emission in paddy field in Greenhouse gas emission in paddy field in Southeast AsiaSoutheast Asia

35

Paddy field experiments in South Sulawesi siteSouth Sulawesi site

Water level 6 cm plot Water level 3 cm plot Farmer’s practice plot

5 m2 m

Barrier Bridge

No Barrier

Syringe 35 ml

Tube Thermometer

Barrier dge

Chamber

ORP meter

Rice

S ilBase of chamberReference electrode

Platinum electrode

36

SoilPlatinum electrode

Gas measurements were CH and N O (7 days interval time) throughGas measurements were CH4 and N2O (7 days interval time) through the cropping time as well as monitoring Eh soil in 5 cm depth.

37

The layout of field measurements and cultivation pattern as water management (3 cm and 6 cm water level) Vs Farmer’s practices

Bases of Fertilizer applied as farmer’s practices (kg ha-1, split time applied) p ( g , p pp )

Urea = 300 ZA = 50 SP-36 = 50 KCl = 50

2) Organic Matter: St t dKCl = 50 + Straw composted

+ Organic manure (Cigulis Var.)

Nurser

Nurser

1) Rice varieties:

Harvesting

ry and Land P 2nd fertilization

ry and Land P 2nd fertilization

Harvesting A

Ciheran and Cigulis

g March 4, 07

Preparation

1st fertilization

Preparation

1st fertilization

August 5, 06

14/0

6

24/0

6

6/3/

06

13/0

6

23/0

6

7/3/

06

13/0

6

23/0

6

8/2/

06

12/0

6

22/0

6

9/1/

06

11/0

6

21/0

6

0/1/

06

11/0

6

21/0

6

31/0

6

10/0

6

20/0

6

30/0

6

10/0

6

20/0

6

30/0

6

1/9/

07

19/0

7

29/0

7

2/8/

07

18/0

7

28/0

7

10/0

7

No cultivation

38

5/ 5/ 6 6/ 6/ 7 7/ 7/ 8 8/ 8/ 9 9/ 9/ 10 10/

10/

10/

11/

11/

11/

12/

12/

12/ 1 1/ 1/ 2 2/ 2/ 3/

Dry season 2006

Date (d / m / y) Raining season 2007

50150250

(mV)

050100150200250

cpitatio

n (m

m)Eh mV (3 cm)

Eh mV (6 cm)Eh mV (Farmer's practice)

mV

)

pita

tion

(mm

)

-250-150-50E

h

-250-200-150-100-500

Preci

810

el (c

m)

Water level 3 cmWater level 6cm(c

m)

Eh (m

Prec

ip

0246

Wat

er le

ve Water level 6cm Farmer's practice

53

Wat

er le

vel

3

4

lux g-C m

-2 day

-1

3 cm6 cm Farmer's practice

g-C

m-2

day

-1

0

1

2

CH4 fl

CH

4flu

x g

0.1

0.2

0.3

mg-N m

-2 h

-1N

m-2

h-1

-0.2

-0.1

0

May-06

May-06

Jun-06

Jun-06

Jul-0

6

Jul-0

6

Aug

-06

Aug

-06

Sep-06

Sep-06

Oct-06

Oct-06

Oct-06

Nov

-06

Nov

-06

Dec-06

Dec-06

Jan-07

Jan-07

Feb-07

Feb-07N2O

flux

N

2O fl

ux m

g-N

39-0.3

0.2N

Fig. One year measurements of CH4 and N2O as affected by water management

Figure. CH4 fluxes as affected by organic matter amendments and water management

5

6 6 cm3 cmFarmers practice

Straw composted amendment

3

4

Farmers practiceamendmentay

-1

1

2

C m

-2da

0

17-D

ec

24-D

ec

31-D

ec

7-Ja

n

14-J

an

21-J

an

28-J

an

4-Fe

b

11-F

eb

18-F

eb

25-F

eb

4

5 6 cm3

Organic manure amendmentH4

flux

g-

2

3

4 3 cmFarmers practice

amendmentCH

0

1

2

40

0

17-D

ec

24-D

ec

31-D

ec

7-Ja

n

14-J

an

21-J

an

28-J

an

4-Fe

b

11-F

eb

18-F

eb

25-F

eb

Table. Total CH4 emission (kg-C ha-1 season-1), N2O emission (kg-N ha-1 season-1), CH4 emission (%) throughout cultivation periods, and grain yield (ton ha-1)

Treatment 3 cm 6 cm Farmer’s practice

1st cultivation

Total CH4 emission 330±64 344±78 519±486

CH4 emission reduction 36.5 33.8 -

Total N2O emission - 0.4±0.5 - 0.1±0.2 - 0.1±0.92

Grain yield 7.2±1.3 7.5±1.7 7.3±0.5

2nd cultivation2 cultivation

Total CH4 emission 231±100 351±32 635±71

CH4 emission reduction 63.6 44.6 -

Total N2O emission 0.0±0.0 - 0.1±0.1 - 0.1±0.8

41Grain yield 7.03±0.5 6.03±0.6 6.53±0.6

Figure. Total CH4 emission and reduction as affected by organic matter amendments and water managementmatter amendments and water management

1

1000

1200Straw compostedOrganic manure1

seas

on-

800

1000 Organic manure

kg-C

ha-1

400

600

H4

flux

k

0

200CH

3 cm 6 cm Farmer's practice (6-10cm)

42

Estimate CH4emission and mitigation potential Geographical distribution of emission in 2000

25.1 25.1 TgTg/yr/yr43

Yan et al 2009

Estimate CH4emission and mitigation potential Baseline (present） Shifting straw incorporate

21.1 21.1 TgTg/yr/yr25.1 25.1 TgTg/yr/yr gg yy

Mid-season drainage Drainage + strawMid season drainage Drainage straw

4417.6 17.6 TgTg/yr/yr21.1 21.1 TgTg/yr/yr

Yan et al., 2009

Irrigation Area in 3 types (Indonesia)Total area of rice field: 4.87 m ha

46%34%

46%Technical

Non-technical

29%

20%Semi-technical25%

46% 10%

12%

Sumatra25%

44%39%

Kalimantan78%

JavaSulawesi 17%

Bali &25%

Bali & Nusa Tenggara

22%29%

4560%15%

49%

Applicability of water-management in South Celebes –management in South Celebes

Farmers’ interview

湛水面積は、南東から西北 湛水に合わせて田植も行われ湛水面積は、南東から西北の海岸部にかけて、次第に拡大する。

る。それにあわせて土地無し農民が次第に南東から西北に移動するため一時的な労働力不足が緩和される。水管理には水利組合P3Aの活用が重要

総面積：6,513 ha

合P3Aの活用が重要。標高低

マロス川より取水

46

Small water-gates to control irrigation

2ndary Canal 11

WUA (Water Use

Gate 1

30cm

10cm

80cm

15cm

15cm

2Association)Gate 2

50cm

Small water-gate

23

Gate 2Gate 3

BlockLand Area:30 ha

イメージ図実際の水田分布形態

47

Land Area:30 haAverage Land Holding: 1.0 ha

実際の水田分布形態を表すものではない。

Mitigation potentials in Asian agroecosystemSources CH4 from paddy

Mitigation Water management OM management

Target area Irrigated paddy inAsia Paddy in Asia

Reduction 35～61% 16～30%Reduction 35 61% 16 30%

Mitigation potential（Mt C yr-1）

Japan：0.6

Asia： 27.3

Japan： 0.5

Asia：12.8

LeakageN2O emission

World：2.7None or little CO2

CostSmall-medium（Infrastructure）

Small（Management）

48Annual GHG in Japan：360 Mt CReduction 6% in Kyoto Protocol： 22 Mt C （Yagi et al., SSCP3a）

View

49http://ws234.niaes.affrc.go.jp/riceface/Introduction_to_RiceFACE/English/sld001.htm

50

51

52

S il Mi bi l BiSoil Microbial BiomassChloroform fumigation extraction

method

Surface (0-1cm; upper) and subsurface (1-10cm; lower) soil samples

Ambient vs. Elevated CO2 (FACE)

Components: Phospholipid fatty acids( f il l )

Nitrogen fixation activity

(surface soil only)MethaneFlux: Closed chamber methodg y

Acetylene reduction method

Surface (0-1cm; upper) & b f

Flux: Closed chamber method

Methanogens and methanotrophs: MPN

subsurface (1-10cm; lower) soil samples

Ambient vs Elevated COSurface (0-1cm; upper) and subsurface (1 10cm; lower) soil samples

53

Ambient vs. Elevated CO2(FACE)(1-10cm; lower) soil samples

Ambient vs. Elevated CO2 (FACE)

Biomass C1000

1200 AU FU AL FL

**

* **m

ass C

soil)

600

800 * *

ial b

iom

C k

g-1s

200

400

Mic

robi

(mg

C

0

0 31 65 94 121

M

Days after transplantingFig. Time-course of soil microbial biomass C in upper (0-1cm) and lower (1-10cm) soil layers of ambient CO2 and

Days after transplanting

) ( ) yFACE paddy fields during the growing season (1999). A (ambient CO2), F (FACE), U and L (upper and lower soil lower soil

54layerlayer, respectively). Significant differences between CO2-treatments are indicated by *(P<0.05) (n=4) by Fisher LSD test.

Biomass N

120140160 AU FU AL FL

*ss

Nl)

6080

100120

biom

askg

-1so

il

204060

robi

al b

mg

N k

0

0 31 65 94 121Mic (m

D ft t l tiDays after transplantingFig. Time-course of soil microbial biomass N in upper (0-1cm) and lower (1-10cm) soil layers of ambient CO2 and FACE paddy ( ) y p yfields during the growing season (1999).A (ambient CO2), F (FACE), U and L (upper and lower soil

55layer, respectively). *(P<0.05) (n=4) by Fisher LSD test.

Biological N2 fixation in Climatron

FACULTY OF HORTICULTURE CHIBA UNIVERSITY

g9

10

Elevated CO 2

6

7

8-1 d

ay-1

Ambient CO

※

※2

4

5

6

ol C

2H

4 g ※

1

2

3

n m

o

※

21 41 63 89 112

0

Days after transplanting

Fig. Acetylene reduction activity of the surface soils (0-1 cm) in Climatron after 2 days incubation at 30 oC.

56※indicate significant difference (P<0.05) between ambient and elevated CO2

treatments.

Biological N2 fixation in Climatron

FACULTY OF HORTICULTURE CHIBA UNIVERSITY

g9

10

-1

Elevated CO2 ※

6

7

8g

-1 d

ay-

Ambient CO2

※

※

※

4

5

6

mol C

2H

4 ※

1

2

3n m

21 41 63 89 1120

Fig. Acetylene reduction activity of the sub-surface soils (below 1 cm) in Climatron after 2 days incubation at 30 oC ※indicate significant difference (P<0.05) between ambient and elevated CO2 treatments.Source: Cheng et al BFS 34:7 13 (2001) also in FACE Hoque et al BFS 34:453 459

57

Source: Cheng et al. BFS 34:7-13 (2001), also in FACE, Hoque et al. BFS 34:453-459 (2001)

Methane emission fromFACULTY OF HORTICULTURE CHIBA UNIVERSITY

CH4

Methane emission from paddy fieldspaddy fields

20

FACEA bi t

1998 season 1999 season 2000 season

10

15

m-2hr

-1

Ambient

5

10

mg

C

00 25 50 75 100

(from May 21, 1998)0 25 50 75 100

(from May 20, 1999)0 25 50 75 100 125

(from May 22, 2000)( y , ) ( y , ) ( y , )

Days after transplanting

Fig. Changes in methane fluxes at FACE and Ambient plots d i h i

58during three rice seasons. Bars indicate standard deviation.

Summary of resultsMicrobial community in floodwater and surface layer soils of paddy field

as affected by elevated COas affected by elevated CO2

Elevated atmospheric CO2Floodwater and surface soil layer

Active sites of microbial activityIncreased CO2 diffusion into

floodwater

Active sites of microbial activity

related to organic matter production

by green algae and cyanobacteria.

Floodwater IncreasedRice

Photo-dependent CO2-fixation (green algae)

Photo-dependent CO2-fixation (green algae)

Other microbes - bacteria, protozoa etc

Biological N2-fixation (cyanobacteria)

crop growth

Increased biomass Changes in diversity Increased biomass Changes in diversity

Increased biomass Changes in diversity

Increased N2 fixation Changes in diversity

Surface soil layer

59Elevated CO2 and the microbiology of paddy soil ecosystem

Aquatic weeds can reduce methane

Soil EhMethane flux ●with weed□ w/o weed

M th id ti ti itMethane oxidation activity

60

Microbial amendment alter methane emission

Application rate( l 2)Chemical fertilizer125h-1

)

30

mgC

m-2

h-1 )

(ml m-2)Chemical fertilizertreatment

50

75

100

125

ane

flux

(mgC

m-2

h

with MMS1 without MMS1 Cont

200

4

Met

hane

flux

(m

0

25

0 20 40 60 80 100 120 140Days after transplanting

Met

ha

10

20

100

M

Rice strawtreatment

100

200

300

400

Eh

(mV

)

with MMS1 without MMS1 cont.

0

59 75 87

Days after transplanting

-300

-200

-100

0

0 20 40 60 80 100 120 140

Soil

E Days after transplanting

Methane flux rate from paddy field with photosynthetic bacteria.

0 20 40 60 80 100 120 140days after transplanting

Seasonal changes of methane flux and soil Eh in pot

p y

61

flux and soil Eh in pot experiment with mainly lactic acid bacteria and yeasts

Kato et al., HortResearch, 2008

Possible enhance on microbial biomass and CH4 emission by elevated CO2

Possible suppress on CH4 emission by CO2

62Source: Chidthaisong 1996

Potentials and Uncertainties of the Options for Mitigating Methane Emissions from Paddy FieldsMethane Emissions from Paddy Fields

“Uncertainties”

U i i f i i d Uncertainties of emission rates and their mitigation potentialsg

Uncertainties for successful design Uncertainties for successful design and implementation of mitigation projectsprojects.

63

Monitoring GHG Emissions by Closed Chamber Techniques

64

Global Estimations for Rice CH4 Emissions4Extrapolations of

laboratory incubated Basing on field data, b t tl f

2 0

300

year

-1)

laboratory incubated paddy soils but mostly from

irrigated paddy fields:

200

250

on (T

g C

H4 ◇ top-down approaches

● bottom-up approaches Mean daily flux = ca. 0.5 g CH4 m-2

150

CH

4 em

issi

o

IPCC FARIPCC AR4

50

100

ated

glo

bal C More field data,

including all the types of paddy fields:IPCC SAR

01960 1970 1980 1990 2000 2010 2020

Est

ima of paddy fields:

Mean daily flux = ca. 0.1-0.3 g CH4 m-2

IPCC SAR

65Year in which estimate was published

IBUKI by JAXAIBUKI by JAXA

66

ConclusionCo c us oMitigation options for methane from paddy fields areMitigation options for methane from paddy fields are

①① Water managementsWater managements

②② Organic matter handlingOrganic matter handling

f hf hStraw incorporation timing, fresh straw > manure or compostStraw incorporation timing, fresh straw > manure or compost

③③ Soil amendmentsSoil amendments③③ Soil amendmentsSoil amendments

Iron materials, microbial materialsIron materials, microbial materials

④④ Improve rice cultivarsImprove rice cultivars

67

Potentials and Uncertainties of the Options for Mitigating Methane Emissions from Paddy Fields

ConclusionsMethane Emissions from Paddy Fields

A number of field measurements have been t d i 1980 d i did t freported since 1980s and various candidates of

mitigation technologies have been proposed. The uncertainty of the effects of mitigation optionsThe uncertainty of the effects of mitigation options

needs to be quantitatively determined and reduced.Possible side effects or trade offs of the mitigationPossible side effects or trade-offs of the mitigation

options, such as reduction of rice yield and increase in CO2 and N2O emissions, are to be 2 2 ,considered.

Cost analysis and ways of giving incentives to

68farmers are needed to be addressed.

Possibility pf technology transfer to developing countries

B i k l d fi d i d l d

developing countries

Basic knowledges are confirmed in developed counries, but not sure yet in developing countries

GHGs from developing countries are much more

can be matched ith s stainable de elopment can be matched with sustainable development

Clean develop mechanism（CDM）is promising to p p gpromore such technology transfer.

69

Thank you for your attention!

Acknowledgements: Oslan Jumadi, Abdul Hadi, Patcharee Lawongsa, Mio Murakami, Hiroki Saito, Jun

70

g , , ,Nishitsuji and Kazuyuki Yagi

Methane emission from rice cultivationLife Cycle Assessment of rice cultivation

100%

75%Rice is our staple food Methane from

Rice fieldAbout 66% is methane (CH4)

50%

Rice field

Transportation

25% Energy input

Ritsumeikan Univ. achievement Resource input0%

1

72