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Increase of CH 4 emission in No-tillage Paddy Soil during Rice Cultivation. Sang Yoon Kim 1) , Jessie Gutierrez 1) , and Pil Joo Kim 1,2)*. - PowerPoint PPT Presentation
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Days after transplanting
40 60 80 100 120
350
400
450
500
550
40 60 80 100 120
8.5
9.0
9.5
10.0
10.5
11.0
11.5Conventional tillageNo-tillage
Tot
al c
arbo
n co
nten
t (g
kg-1
)
Hot
wat
er e
xtra
ctab
le C
(m
g kg
-1)
Rice growth stages
Maximum tillering Panicle initiation
mcrA
gen
e co
py n
umbe
rs g
-1 d
ried
soil
2.0e+6
4.0e+6
6.0e+6
5th year (2010)2nd (CL)
Maximum tillering Panicle initiation
mcrA
gen
e co
py n
umbe
rs g
-1 d
ried
soil
2.0e+6
4.0e+6
6.0e+6
Conventional tillageNo-tillage
2th year (2007)
1Division of Applied Life Science (BK 21 program), Graduate School, Gyeongsang National University, Jinju, 660-701, South Korea, [email protected] of Agriculture and Life Sciences, Gyeongsang National University , Jinju, 660-701, South Korea, [email protected]
Sang Yoon Kim1), Jessie Gutierrez1), and Pil Joo Kim1,2)*
Increase of CH4 emission in No-tillage Paddy Soil during Rice Cultivation
Research background Recently, no-till systems (NT) have been used in paddy field in
some eastern Asian countries and several studies were carried
out to investigate the relationship between methane emission and
tillage management. Most of previous studies reported that
seasonal CH4 fluxes were decreased by more than 50% due to
reduced mineralization of organic matter in NT soils. However,
long-term NT might stimulate more CH4 emission during rice
cultivation due to increased accumulation of total organic carbon
in paddy soil.
The objective of this study was to determine the effect of two different tillage
systems : conventional tillage (CT) and no-tillage (NT) on CH4 emissions in paddy soil
during rice cultivation.
Objectives
Materials and Methods
Conclusions
2nd year (2007)
Days after transplanting
20 40 60 80 100 120
CH
4 e
mis
sion
rat
e (m
g m
-2 h
-1)
0
10
20
30
40
50
60
20 40 60 80 100 120
0
10
20
30
40
50
60
Conventional tillageNo-tillage
5th year (2010)
CH
4 e
mis
sion
rat
e (m
g m
-2 h
-1)
1. Investigation site GNU Ricefield Experimental Plot , Jinju City, Korea
2. Rice cultivation and fertilization backgroundCultivar: Dongjinbyeo (Oryza sativa L. Japonica)Fertilization : N-P2O5-K2O = 90-45-58 kg ha -1
3. CH4 gas sampling and analysisGas sampling : Closed chamber method at 10:30 AM for 30 minutes twice in a weekGas chromatography (Shimadzu, GC2010 with FID) 4. Methanogenic activitySoil sampling: 35DAT and 70DAT soil sampleTotal DNA extraction by Fast DNA SPIN Kit (MP Bio)Real time PCR condition for mcrA gene analysis - Methanogens: 95oC for 5 min, 40 cycles at 94oC for 45 sec, 55oC for 45 sec and 72oC for 45 sec - Primer selection • Methanogens (ML-F/ML-R)
5. Soil chemical properties and plant growth characteristicsSoil sampling: harvesting stageSoil physical and chemical properties
- Bulk density, porosity, total C, hot H2O-extractable CPlant growth and yield characteristics - Plant height, tiller number, straw yield and rice yield
Experimental site descriptionYear after no-tillage system installation
0
10
20
30
40
50
Conventional tillageNo-tillage
1st5th2nd
To
tal C
H4 flu
x (g
m-2
)
Location 35° 06’ 32.67’’ N, 128° 07’ 06.57’’E
Year after no-tillage system Installation 2nd and 5th year(2006-2010)
Soil texture Silty Clay Loam (SiCL)
ML-F: GGT GGT GTM GGA TTC ACA CAR TAY GCW ACA GCML-R: TTC ATT GCR TAG TTW GGR TAG TT
Results and Discussions
Fig. 1. Changes of CH4 emission patterns in paddy soil during rice cultivation as influenced by conventional tillage and no-tillage in different
tillage year.
Table 1. Physical and chemical properties of paddy soil in conventional tillage(CT) and no tillage (NT) cultivation systems at rice harvest in 2nd and 5th in, respectively
Fig. 3. Changes of total and hot water-extractable C concentrations during rice cultivation in soil in the 5th year after installation.
Fig. 4. Changes of mcrA gene copy number at different rice growing stage in the 2nd and 5th year after installation.
Conventional tillage system could significantly affect CH4 emission. In contrast, no-tillage reduced CH4 emission during rice cultivation only in a short term period.
Aside from the improvement of soil physical properties, continued no-tillage practice was more effective than conventional tillage to accumulate more organic matter in soil.
Increased accumulation of soil organic carbon may had provided more methanogenic substrates as hot water extractable C that enhanced more methanogenic activity during rice cultivation and increased CH4 emission.
Long-term no-tillage investigations are needed to firmly establish the other factors for the occurrence of higher CH4 emissions with no-tillage practices in paddy soils.
Parameters Experimental Plots
2nd years Plot 2 (5th years)
CT NT CT NT
Soil properties
Bulk density ( g cm-3) Porosity (%) Organic matter (mg kg-1)
Plant growth characteristics
Plant height (cm) Tiller number per hill Total biomass Straw biomass (g m-2) Grain yield (g m-2)
1.2552.024.9
101.015.0
650.0678.3
1.17
56.0
25.0
100.0
14.3
621.0
642.2
1.1257.728.1
105.014.0
940.6752.8
1.07
59.6
34.5
100.2
12.0
778.5
733.3Fig. 2. Total CH4 flux during rice cultivation as influenced by
conventional tillage and no-tillage in different tillage year.