Attachai JintrawetMultiple Cropping Center, Chiang Mai Univ., Chiang Mai.

& Kim C. Nguyen, Atmospheric Res. Center, CSIRO.

@ Sasin Graduate School of Management, Chulalongkorn University, Sasapatasala Building, room 521.

Simulating impacts of future climate on rice and human in CNX, KKC Thailand

Rice production systems and climate changesStudy methodsResultsSummary

Issues

Global carbon cycle and stocksA t m o s p h e r e = 7 6 0

A c c u m u l a t i o n 3 . 3 0 . 2

V e g e t a t i o n = 5 0 0

S o i l s a n d d e t r i t u s = 2 0 0 0

= 2 5 0 0

O c e a n = 3 9 0 0 0

F o s s i l O r g a n i c C & C a r b o n a t e m i n e r a l s

> 6 0 0 0

R u n o f f = 0 . 8

F o s s i l F u e l s a n d C e m e n t P r o d u c t i o n 6 . 3 0 . 6

N e t T e r r e s t r i a l U p t a k e 0 . 7 ± 1 . 0

N e t O c e a n u p t a k e 2 . 3 ± 0 . 8

A i r / S e a E x c h a n g e = 9 0

S e d i m e n t a t i o n = 0 . 2

R e s p i r a t i o n a n d F i r e = 6 0

G l o b a l N e t P r i m a r y P r o d u c t i v i t y

A t m o s p h e r e = 7 6 0A c c u m u l a t i o n 3 . 3 0 . 2

V e g e t a t i o n = 5 0 0

S o i l s a n d d e t r i t u s = 2 0 0 0

= 2 5 0 0

O c e a n = 3 9 0 0 0

F o s s i l O r g a n i c C & C a r b o n a t e m i n e r a l s

> 6 0 0 0

R u n o f f = 0 . 8

F o s s i l F u e l s a n d C e m e n t P r o d u c t i o n 6 . 3 0 . 6

N e t T e r r e s t r i a l U p t a k e 0 . 7 ± 1 . 0

N e t O c e a n u p t a k e 2 . 3 ± 0 . 8

A i r / S e a E x c h a n g e = 9 0

A i r / S e a E x c h a n g e = 9 0

S e d i m e n t a t i o n = 0 . 2

R e s p i r a t i o n a n d F i r e = 6 0

G l o b a l N e t P r i m a r y P r o d u c t i v i t y

Thailand carries 1 million ha of riceland

Rice yield (kg ha-1) and population

0

2,500

5,000

Thailand: 65 Millions

KK = 1.8 Millions

CNX = 1.6 Millions

1974 84 94 00

OAE, 1975-2001

Historical weather data

KK, CM1985-99

Study tools

KK using Roi Et soilCM using San Sai soil

NSPT glutinous riceRD23 non-glutinous rice

Predicted Regional GCM scenario weather

dataKK, CM

1985-19992006-2025

VS

+

CERES-Rice

GFDL-MK3 climate model

Scenario 1: 1985-1999Irrigation Irrigated

RD23 NSPT

MK3MK3WTH

Rainfed

RD23 NSPT

MK3MK3WTH

Rice variety

Weather data

Scenario 1 = 1xCO2 b/w 1985-1999 Using WTH & MK3

WTH WTH

Scenario 2 = 2xCO2 b/w 2006-2025 Using MK3

1985 1999

2006 2025 2035 2045 2055 2064

Urea

Green manure

WTH

Scenario 2: 2006-2025Irrigation Irrigated

RD23 NSPT

MK3MK3

Rainfed

RD23 NSPT

MK3MK3

Rice variety

Weather data

Scenario 2 = 2xCO2 b/w 2006-2025 using MK3

1985 1999

2006 2025 2035 2045 2055 2064

Urea 0, 37.5, 75 kg ha-1 0.5, 2, 4 Mg ha-1

Total of 12 management rice production strategies

Scenario 1 between 1985-1999

ProvincesWaterRice variety WTH MK3 OAE

KKC 2.20 0.89 1.67

RD 23. 2.63 1.00 1.67

NSPT 2.58 2.48 1.67

3.08 3.26 1.67

CNX NSPT 3.54 2.64 3.33

4.20 2.98 3.33

NSPT 4.03 3.98 3.33

4.77 5.16 3.33

Rainfed

Rainfed

Irrigated

Irrigated

RD 23

RD 23

RD 23

NSPT

Rice yield (Mg ha-1)

RMSE 1.00 1.03

RMSE 0.91 1.04

Rainfall between 1980-2030

0

500

1,000

1,500

2,000

2,500

๒๕๒๓1980

๒๕๓๓1990

๒๕๔๓2000

๒๕๕๓2010

๒๕๖๓2020

๒๕๗๓2030

CNX

KKC

Scenario 2 b/w 2006-2024

Rainfed Irrigated

0 37.5 75 0 37.5 75

NSPT 0.78 1.50 1.99 1.71 2.69 3.04

Rice yield at KKC (Mg ha-1)

Rice var GM (kg ha-1)

6000

500 0.74 1.48 1.97 1.54 2.53 2.89

RD23 0.90 1.76 2.35 2.27 3.58 4.016000

500 0.84 1.73 2.33 1.96 3.31 3.76

Urea (kg ha-1) Urea (kg ha-1)

Scenario 2 b/w 2006-2024

Rainfed Irrigated

0 37.5 75 0 37.5 75

NSPT 5.60 5.73 5.94 7.74 7.86 8.04

Rice yield at CNX (Mg ha-1)

Rice var GM (kg ha-1)

6000

500 2.70 3.43 4.07 3.83 4.37 4.87

RD23 6.56 6.67 6.89 9.88 10.00 10.216000

500 3.20 4.24 5.09 1.96 5.78 6.43

Urea (kg ha-1) Urea (kg ha-1)

Impacts of the changes

• At CNX, simulated rice yields appeared to be higher than the current level.

• At KKC, simulated rice yields appeared to be lower than the current level.

• Flooding and soil erosion

Impacts of high rainfall

• Too much moisture in harvested products, use more energy to dry

• More leaching

• Less efficiency of chemical fertilizer

Summary

• It is possible to use a process-oriented rice model to simulate the production under various climatic, edaphic, and management conditions

• Slight impact on rice production during the next 20 years, except much higher rainfall volume in CNX areas.

• Need to develop warning systems.