Characteristics of CO2 and CH4 flux at barley-rice double cropping field in southern part of Okayama

Takimoto, Tetsuya; Iwata, Toru; Yamamoto, Susumu; Miura, Takuya

doi:10.2480/agrmet.66.3.5

Cited by 8 publications

(3 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Crop residue was burned in some parts of the target paddy in 2005 and 2006 before its incorporation. An observational study conducted in a farmer's field located in western Japan found that 31% of rice residues were burned after harvesting (Takimoto et al , ). In our case, the burned area approximated 25% of the target field by a photo‐based field survey.…”

Section: Methodsmentioning

confidence: 99%

Environmental Controls on Fallow Carbon Dioxide Flux in a Single‐Crop Rice Paddy, Japan

et al. 2013

View full text Add to dashboard Cite

Soil organic carbon (SOC) is one of the important measures of soil fertility and sustainability in arable lands. With continuous CO 2 flux measurements, this study assessed the SOC decomposition and its environmental controls at both half-hourly and season-long scales in a single-crop rice (Oryza sativa L.) paddy during three fallow periods between 2004 and 2007. Measurements were made on a gray lowland soil sited in eastern Japan using the eddy covariance method. Ecosystem respiration was strongly affected by soil water content measured at 0-0Á1 m depth. At 0Á5 m 3 m À 3 or more of soil water content, the baseline of ecosystem respiration decreased by 50% compared with that at 0Á2 m 3 m À 3 . The effect was quantified at half-hourly scale using an empirical multiple regression model, together with the soil surface temperature and the time after residue incorporation. At season-long scale, net biome production, which is equivalent to the change in the SOC pool during the fallow period, was estimated from the flux and ancillary data at 150 g C m À 2 in 2004-2005, 70 g m À 2 in 2005-2006, and 270 g C m À 2 in 2006-2007. Apparently, as much as 46 to 79% of the soil organic matter incorporated (crop residues, ratoon, and stable manure) was decomposed during the fallow period. Precipitation, or associated soil water content, was important for the carbon balance of the field at season-long scale because of its large interannual variability and relatively low permeability of the paddy soil.

show abstract

Section: Methodsmentioning

confidence: 99%

Environmental Controls on Fallow Carbon Dioxide Flux in a Single‐Crop Rice Paddy, Japan

et al. 2013

View full text Add to dashboard Cite

show abstract

“…The dominant control of solar radiation on ET in our study was likely attributed to the relatively high year-to-year variation in solar radiation at our study site. Draining the rice paddy water is an important agricultural practice that affects both carbon emissions from the soil Miyata et al, 2000;Takimoto et al, 2010 and energy balance Tsukamoto, 1993;Harazono et al, 1998 . At our study site, the drainage was typically implemented from mid-June to mid-July DAT = 55 -73, on average and lasted for a few weeks.…”

Section: Rice Et and E Pmentioning

confidence: 99%

Evapotranspiration in a rice paddy field over 13 crop years

Ikawa

Ono

Mano

et al. 2017

J. Agric. Meteorol.

Self Cite

View full text Add to dashboard Cite

Evapotranspiration ET in rice paddy fields has been studied over the past half-century, but despite that long history of rice ET study, not much is known about their inter-annual variation. This study investigates ET in rice paddy fields during the growing season for 13 years 2002 -2014 at one of the longest flux monitoring sites in Japan. The cumulative ET estimated for each growing season 120 days after transplanting was 419 45 SD standard deviation mm/season 3.5 mm d 1 , which increased to 534 64 mm/season 4.4 mm d 1 when energy balance was forced toclose. This study determined that ET was correlated with meteorological conditions defined by potential evaporation E P , and the inter-annual variability of seasonal ET/E P coefficient of variation CV = 4.6 was less than half the variability of ET CV = 10.7 . For most years, the seasonal ET was reasonably estimated as the product of E P and the overall average ET/E P =0.89 , including years that experienced both extremely warm and cold summers. However, the errors in estimation were relatively large for 2008 which experienced high precipitation and 2012 which was characterized by an extremely low leaf area index . Although the seasonal ET/E P was relatively invariable among years, both the seasonal trends of ET and ET/E P greatly differed between years. The inter-annual variability in ET/E P was particularly high at the ripening stage defined as 91 -120 days after transplanting . The ET/E P at this stage was well correlated to precipitation, and the variation was possibly caused by evaporation from intercepted rainfall. The variation in ET/E P associated with precipitation at the ripening stage accounted for 21 of the inter-annual variation of seasonal ET/E P .

show abstract

“…Previously, this method was applied in ecosystems that represented well-known methane sources, such as rice paddies (Miyata et al 2000;Takimoto et al 2010), natural wetlands (Friborg and Christensen 1997;Simpson et al 1997;Werner et al 2003;Rinne et al 2007), and tundra Wille et al 2008). However, relatively few studies have been conducted in forest ecosystems (Ueyama et al 2006;Smeets et al 2009), probably because the measurements of small methane uptakes is much more difficult than the measurement of fluxes from large sources.…”

Section: Introductionmentioning

confidence: 99%

Continuous measurement of methane flux over a larch forest using a relaxed eddy accumulation method

Ueyama

Hamotani

Nishimura

et al. 2012

Theor Appl Climatol

View full text Add to dashboard Cite

We measured the methane flux of a forest canopy throughout a year using a relaxed eddy accumulation (REA) method. This sampling system was carefully validated against heat and CO 2 fluxes measured by the eddy covariance method. Although the sampling system was robust, there were large uncertainties in the measured methane fluxes because of the limited precision of the methane gas analyzer. Based on the spectral characteristics of signals from the methane analyzer and the diurnal variations in the standard deviation of the vertical wind velocity, we found the daytime and nighttime precision of halfhourly methane flux measurements to be approximately 1.2 and 0.7 μg CH 4 m −2 s −1 , respectively. Additional uncertainties caused by the dilution effect were estimated to affect the accuracy by as much as 0.21 μg CH 4 m −2 s −1 on a half-hourly basis. Diurnal and seasonal variations were observed in the measured fluxes. The biological emission from plant leaves was not observed in our studies, and thus could be negligible at the canopy-scale exchange. The annual methane sink was 835±175 mg CH 4 m −2 year −1 (8.35 kg CH 4 ha −1 year −1 ), which was comparable to the flux range of 379-2,478 mg CH 4 m −2 year −1 previously measured in other Japanese forest soils. This study indicated that the REA method could be a promising technique to measure canopy scale methane fluxes over forests, but further improvement of precision of the analyzer will be required.

show abstract

Characteristics of CO2 and CH4 flux at barley-rice double cropping field in southern part of Okayama

Cited by 8 publications

References 19 publications

Environmental Controls on Fallow Carbon Dioxide Flux in a Single‐Crop Rice Paddy, Japan

Environmental Controls on Fallow Carbon Dioxide Flux in a Single‐Crop Rice Paddy, Japan

Evapotranspiration in a rice paddy field over 13 crop years

Continuous measurement of methane flux over a larch forest using a relaxed eddy accumulation method

Contact Info

Product

Resources

About