Modifying water management for rice production

BUT  

Rice  is  not  just  a  vic1m  of  climate  change,  

it  is  also  one  of  the  causes  

How  methane  is  produced  by  irrigated  rice  

=> Rice fields account for 5 -20 % of all global methane sources

‘Closed Chamber‘ Method

Diurnal patterns

Pooled field data, Buendia et al. 1997

Relevance for CCAFS?

One of the Fund Council comments:

o Articulate potential contribution to development of global standards for measuring GHG emissions from agriculture

16 Jan 2009 7 Unit plot size: 5 x 5 m

Field stations of the Intenational Rice Research Institute (projects funded by US-EPA and UNDP/ GEF)

Irrigated Rainfed Deepwater

IRRI/ Los Banos

View of the field

chambers (for flooded/ non-flooded

condition)

Days after planting

Mid-season drainage

Field experiment at Hangzhou, China (Wassmann et al., 2000)

‘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

"   downward flux – atmospheric CO2 taken up by the rice plant for photosynthesis

"   upward flux – CO2 being released from ecosystem respiration

Modelling emissions using DNDC model (DeNitrification-DeComposition)

from Li et al. 2000

Inputs

SOIL Texture, pH, 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)

SOIL PROFILES (C and N contents, moisture etc.)

CROP PHENOLOGY (biomass etc)

=> for 28 crops

from Matthews et al. 2000

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