The document discusses the impact of rice cultivation on methane emissions and highlights the need for improved water management strategies in rice production. It emphasizes the importance of site-specific nutrient management and the use of models to assess greenhouse gas emissions linked to rice farming. The conclusion stresses the necessity for enhanced efficiency in water use, fertilizer uptake, and overall resource management to mitigate these emissions.

1. Modifying water management
for rice production

2. BUT
Rice
is
not
just
a
vic1m
of
climate
change,
it
is
also
one
of
the
causes

3. How
methane
is
produced
by
irrigated
rice
=> Rice fields account for 5 -20 % of all global
methane sources

4. ‘Closed Chamber‘ Method

5. Diurnal patterns
Pooled field data, Buendia et al. 1997

6. Relevance for CCAFS?
One of the Fund Council comments:
o Articulate potential contribution to
development of global standards for
measuring GHG emissions from
agriculture

7. Unit plot size: 5 x 5 m

8. Field stations of the Intenational Rice Research
Institute (projects funded by US-EPA and UNDP/ GEF)
IRRI/
Los Banos
Irrigated
Rainfed
Deepwater

9. View of the
field
chambers
(for flooded/
non-flooded
condition)

10. Mid-season drainage
Days after planting
Field experiment at Hangzhou, China (Wassmann et al., 2000)

12. ‘Site-Specific Nutrient
Management’ (SSNM)
 Applying nutrients as
and when needed
 Adjusting nutrient
application to crop
needs in given
location and season
Leaf Color Chart

15. " downward flux – atmospheric CO2 taken up by
the rice plant for photosynthesis
" upward flux – CO2 being released from
ecosystem respiration

16. Modelling emissions using DNDC model
(DeNitrification-DeComposition)
Inputs
SOIL
Texture, pH, => for 28 crops
C and N content
CLIMATE
Temp., rainfall
MANAGEMENT
N inputs, tillage,
irrigation etc.
Outputs
EMISSIONS (CO2, CH4 , N2O, NO, NO2, NH3 )
WATER BALANCE (Evaporation, transpiration)
from Li et al.
2000 SOIL PROFILES (C and N contents, moisture etc.)
CROP PHENOLOGY (biomass etc)

17. from
Matthews
et al. 2000

18. Conclusion
Mitigation:
Rice systems have to
become more efficient
in terms of…
• Water use
• Fertilizer uptake
• Harvest index
Challenges of Mitigation =
Challenges of advanced resource management