Author: R. Mahender Kumar Title: Rice Systems Comparisons - Agronomic Effects and GHG Emissions Presented at: The 5th International Rice Congress (SRI research side event) Venue: Sands Expo and Convention Centre, Singapore Date: October 16, 2018

1. Indian
Institute of
Rice Research-
IndiaDr. R.Mahender Kumar
Head ( Agronomy)
PI- AICRIP AGRONOMY
IIRR- Hyderabad, India, kumarrm21364@gmail.com
Rice systems comparisons-agronomic effects and GHG emissions
Rice systems comparisons -
agronomic effects
and GHG emissions
Panel discussion (Water GHG and SRI method) IRC
-2018 on 16102018

2. Diversity in rice ecologies
Irrigated
Hill rice
Uplands
Shallow LL
SDW&DW
Panel discussion (Water GHG and SRI method)
IRC -2018 on 16102018

3. Focus of Research
• To assess the effects of establishment techniques,
water and weed management practices on growth
and yield of rice
• To assess the methane (CH4) and nitrous oxide
(N2O) emission as influenced by method of
planting, water and weed management practices

4. Methodology
• Location: IIRR, Hyderabad
• Design: Split-split-plot
• Replications: 4
Treatment details
• Main plots: M1: SRI
M2: Conventional
M3: Mechanized
• Sub plots: I1: Flooding
I2: Saturation
I3 : AWD
Sub-sub: W1: Chemical control
W2: Cono-weeding

5. Different steps followed in SRI

8. Testing of Sensor based water management in rice at IIRR

9. Total quantity (I+Er) of water applied (mm) and water productivity (kg
m-3
) as
influenced by different treatments (pooled)
0
200
400
600
800
1000
1200
1400
1600
M1 M2 M3 I1 I2 I3 W1 W2
Establishment techniques Irrigation methods Weed
management
practices
Totalwaterapplied(mm)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Waterproductivity(kgm-3
)
Total water applied (mm) Kharif Total water applied (mm) Rabi
Water productivity (kg m-3) Kharif Water productivity (kg m-3) Rabi
M1: SRI, M2: NTP, M3: Mechanized transplanting I1: Flooding, I2: Saturation, I3: AWD (5 days interval);
W1: Four time cono-weeding at 10, 20, 30 and 40 DAT; W2: Butachlor fb Bispyribac sodium

10. 0
10
20
30
40
50
60
70
M1 M2 M3 I1 I2 I3 W1 W2
Establishment techniques Irrigation methods Weed
management
practices
TREATMENTS
Methaneemission(mgm
-2
day
-1
)
Vegetative stage Maximum tillering Panicle initiation Maturity
Methane emission by rice flood water as influenced by transplanting methods, irrigation
water levels and weed management practices

11. -1.5
-1
-0.5
0
0.5
1
1.5
Total
quantity of
water
applied
Dissolved
oxygen
Yield Straw Dry matter
production
Number of
tillers m-2
N uptake
PARAMETERS
'r'value
Methane Kharif Methane Rabi
Nitrous oxide Kharif Nitrous oxide Rabi
Correlation co-efficient between methane and nitrous oxide emission with other growth and yield
components of rice as influenced by treatments

12. Water saving / SRI enhances carbon
sinks and decreases the emission of
GHGs• Expansion of carbon sinks
- SRI/ AWD rice plants sequester more carbon – higher grain and
straw yield, and more root biomass
- Increased soil organic matter through SRI practices that
improve the soil with more organic matter application and
increased root exudates
- Association agro – ecological practices sequester carbon,
such as green manure production , integration with
agroforestry, surface mulch applications, etc.
- Reduced carbon footprint due to reduced agrochemical
use (including the manufacturing, and shipping of
agrochemicals)
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13. Conclusions
 SRI method is the best practice for getting higher yield, water use efficiency
and effectively managing weeds.
 Alternate wetting and drying (AWD) helps to mitigate CH4 emission by 41
per cent than continuous flooding along with 19 per cent saving of
irrigation water over continuous flooding.
 Cono-weeding improves the physico-chemical condition of the soil and hence
leads to 13.6 to 16.8 per cent increase in yield with 5.5 to 6.1 per cent CH4
mitigation.
 Mechanised transplanting is economical in terms of monitory returns by
reducing labour requirement at peak season with uniform time and depth of
transplanting.
 Treatment combination of SRI with alternate wetting and drying and cono-
weeding recorded higher net return, gross return and B:C ratio compared to
other treatment combinations.

14. Reduced emission of greenhouse gases
(GHGs) from paddy soils
• Methane (CH4) is reduced by between 41 % as soils are maintained
under mostly aerobic conditions
• Nitrous oxide (N2O) is only slightly increased or sometimes reduced
as use of N fertilizers is reduced; N2O increased do not offset CH4
reductions, so GWP is reduced
• Total global warning potential (GWP) from flooded rice paddies
is reduced significantly
Mangem Training- Certified Farm advisory course-
26-09-2018

15. Thank you.
Panel discussion (Water GHG and SRI method) IRC
-2018 on 16102018