Seasonal trends and environmental controls of methane emissions in a rice paddy field in Northern Italy

Abstract. Rice paddy fields are one of the greatest anthropogenic sources of methane (CH4), the third most important greenhouse gas after water vapour and carbon dioxide. In agricultural fields, CH4 is usually measured with the closed chamber technique, resulting in discontinuous series of measurements performed over a limited area, that generally do not provide sufficient information on the short-term variation of the fluxes. On the contrary, aerodynamic techniques have been rarely applied for the measurement of CH4 fluxes in rice paddy fields. The eddy covariance (EC) technique provides integrated continuous measurements over a large area and may increase our understanding of the underlying processes and diurnal and seasonal pattern of CH4 emissions in this ecosystem. For this purpose a Fast Methane Analyzer (Los Gatos Research Ltd.) was installed in a rice paddy field in the Po Valley (Northern Italy). Methane fluxes were measured during the rice growing season with both EC and manually operated closed chambers. Methane fluxes were strongly influenced by the height of the water table, with emissions peaking when it was above 10–12 cm. Soil temperature and the developmental stage of rice plants were also responsible of the seasonal variation on the fluxes. The measured EC fluxes showed a diurnal cycle in the emissions, which was more relevant during the vegetative period, and with CH4 emissions being higher in the late evening, possibly associated with higher water temperature. The comparison between the two measurement techniques shows that greater fluxes are measured with the chambers, especially when higher fluxes are being produced, resulting in 30 % higher seasonal estimations with the chambers than with the EC (41.1 and 31.7 g CH4 m−2 measured with chambers and EC respectively) and even greater differences are found if shorter periods with high chamber sampling frequency are compared. The differences may be a result of the combined effect of overestimation with the chambers and of the possible underestimation by the EC technique.

Download Full-text

Seasonal trends and environmental controls of methane emissions in a rice paddy field in Northern Italy

Biogeosciences Discussions ◽

10.5194/bgd-8-8999-2011 ◽

2011 ◽

Vol 8 (5) ◽

pp. 8999-9032 ◽

Cited By ~ 5

Author(s):

A. Meijide ◽

G. Manca ◽

I. Goded ◽

V. Magliulo ◽

P. di Tommasi ◽

...

Keyword(s):

Eddy Covariance ◽

Water Table ◽

Paddy Field ◽

Rice Paddy ◽

Northern Italy ◽

Paddy Fields ◽

Rice Paddy Field ◽

Ch4 Emissions ◽

Methane Fluxes ◽

Rice Paddy Fields

Abstract. Rice paddy fields are one of the greatest anthropogenic sources of methane (CH4), the third most important greenhouse gas after water vapour and carbon dioxide. In agricultural fields, CH4 is usually measured with the closed chamber technique, resulting in discontinuous series of measurements performed over a limited area, that generally do not provide sufficient information on the short-term variation of the fluxes. On the contrary, aerodynamic techniques have been rarely applied for the measurement of CH4 fluxes in rice paddy fields. The eddy covariance (EC) technique provides integrated continuous measurements over a large area and may increase our understanding of the underlying processes and diurnal and seasonal pattern of CH4 emissions in this ecosystem. For this purpose a Fast Methane Analyzer (Los Gatos Research Ltd.) was installed in an eddy-covariance field set-up in a rice paddy field in the Po Valley (Northern Italy). Methane fluxes were measured during the rice growing season, both with EC and with manually operated closed chambers. Methane fluxes were strongly influenced by the presence of the water table, with emissions peaking when it was above 10–12 cm. Further studies are required to evaluate if water table management could decrease CH4 emissions. The development of rice plants and soil temperature were also responsible of the seasonal variation on the fluxes. The EC measured showed a diurnal cycle in the emissions, which was more relevant during the vegetative period, and with CH4 emissions being higher in the late evening, possibly associated with higher water temperature. The comparison between both measurement techniques shows that greater fluxes are measured with the chambers, especially when higher fluxes are being produced, resulting in 30 % higher seasonal estimations with the chambers than with the EC (41.1 and 31.8 g CH4 m−2 measured with chambers and EC respectively). The differences may be a result of the combined effect of overestimation with the chambers, the possible underestimation by the EC technique and of not having considered the daily course of the fluxes for the calculation of seasonal emissions from chambers.

Download Full-text

Eddy correlation measurements of methane fluxes from Italian rice-paddy fields

10.1117/12.366467 ◽

1999 ◽

Cited By ~ 1

Author(s):

Peter W. Werle

Keyword(s):

Rice Paddy ◽

Eddy Correlation ◽

Paddy Fields ◽

Methane Fluxes ◽

Rice Paddy Fields

Download Full-text

Comparison of Closed Chamber and Eddy Covariance Methods to Improve the Understanding of Methane Fluxes from Rice Paddy Fields in Japan

Atmosphere ◽

10.3390/atmos9090356 ◽

2018 ◽

Vol 9 (9) ◽

pp. 356 ◽

Cited By ~ 6

Author(s):

Nongpat Chaichana ◽

Sonoko Bellingrath-Kimura ◽

Shujiro Komiya ◽

Yoshiharu Fujii ◽

Kosuke Noborio ◽

...

Keyword(s):

Eddy Covariance ◽

Rice Paddy ◽

Paddy Fields ◽

Closed Chamber ◽

Cropping Season ◽

Greenhouse Gas Flux ◽

Land Use Types ◽

Methane Fluxes ◽

Footprint Analysis ◽

Rice Paddy Fields

Greenhouse gas flux monitoring in ecosystems is mostly conducted by closed chamber and eddy covariance techniques. To determine the relevance of the two methods in rice paddy fields at different growing stages, closed chamber (CC) and eddy covariance (EC) methods were used to measure the methane (CH4) fluxes in a flooded rice paddy field. Intensive monitoring using the CC method was conducted at 30, 60 and 90 days after transplanting (DAT) and after harvest (AHV). An EC tower was installed at the centre of the experimental site to provide continuous measurements during the rice cropping season. The CC method resulted in CH4 flux averages that were 58%, 81%, 94% and 57% higher than those measured by the EC method at 30, 60 and 90 DAT and after harvest (AHV), respectively. A footprint analysis showed that the area covered by the EC method in this study included non-homogeneous land use types. The different strengths and weaknesses of the CC and EC methods can complement each other, and the use of both methods together leads to a better understanding of CH4 emissions from paddy fields.

Download Full-text

Optimizing grain yields reduces CH4 emissions from rice paddy fields

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.192276599 ◽

2002 ◽

Vol 99 (19) ◽

pp. 12021-12024 ◽

Cited By ~ 75

Author(s):

H. A. C. Denier van der Gon ◽

M. J. Kropff ◽

N. van Breemen ◽

R. Wassmann ◽

R. S. Lantin ◽

...

Keyword(s):

Rice Paddy ◽

Paddy Fields ◽

Grain Yields ◽

Ch4 Emissions ◽

Rice Paddy Fields

Download Full-text

Tunable diode laser measurements of methane fluxes from an irrigated rice paddy field in the Philippines

Journal of Geophysical Research Atmospheres ◽

10.1029/94jd03326 ◽

1995 ◽

Vol 100 (D4) ◽

pp. 7283-7290 ◽

Cited By ~ 40

Author(s):

I. J. Simpson ◽

G. W. Thurtell ◽

G. E. Kidd ◽

M. Lin ◽

T. H. Demetriades-Shah ◽

...

Keyword(s):

Diode Laser ◽

Paddy Field ◽

Rice Paddy ◽

The Philippines ◽

Tunable Diode Laser ◽

Irrigated Rice ◽

Rice Paddy Field ◽

Laser Measurements ◽

Methane Fluxes

Download Full-text

Influence of tillage practice on major pathways of CH4 emission in rice paddy field

10.5194/egusphere-egu21-3912 ◽

2021 ◽

Author(s):

Hiyori Namie ◽

kasane Shimada ◽

Shuang shuang Zhao ◽

Munehide Ishiguro ◽

Ryusuke Hatanano

Keyword(s):

Organic Matter ◽

Diffusion Coefficient ◽

Paddy Field ◽

Rice Paddy ◽

Gas Diffusion ◽

Rice Cultivation ◽

Paddy Fields ◽

Rice Paddy Field ◽

Intermittent Irrigation ◽

Irrigation Drainage

&#160;Generally, during the paddy rice cultivation period, CH4 produced in the soil is reported to be released to the atmosphere through three pathways: diffusion (<1%), bubbles (<10%), and via rice (> 90%). However, there are few studies have measured gas diffusion coefficient for soil below surface of the water, and there is no study has provided an accurate understanding of CH4 dynamics in paddy fields. Furthermore, there are few studies that understanding the CH4 dynamics in fertilizer-free and pesticide-free paddy fields, which is mainly controlled by inter-tillage practices. Therefore, this study aimed to clarify the effects of tillage and the number of inter-tillage and the presence or absence of fertilizer and pesticide on the CH4 dynamics in rice paddy soil. This study compared three types of CH4 flux, which were total CH4 flux from rice paddy field measured by transparent chamber with plants, and soil derived CH4 flux measured by dark chamber without plants, and gas diffusion flux calculated as a product of the gas diffusion coefficient and measured soil gas concentration gradient at the depths of 0-5 and 5-10cm. And they were compared with in the five rice cultivation periods (flooding, mid-drying, intermittent irrigation, drainage, and fallowing) and in the four treatment plots (conventional farming (CF), and fertilizer- and pesticide-free farming with zero-inter-tillage(T0), two-inter-tillage(T2), and five-inter-tillage (T5)). The CF was conducted according to the regional recommendation for tillage, fertilization and pest and weed control. The results showed that the peak of total CH4 flux was observed in the mid-drying and intermittent irrigation periods in all treatments, and that the CH4 flux via rice plant accounted for 60-90% of the total CH4 flux. The CF showed significantly highest CH4 emission during the periods, and the increase of the number of inter-tillage tended to increase the CH4 emission. In the drainage period, the CH4 flux by bubbles in the CF and T5 accounted for more than 80% of the total CH4 flux. In the fallowing period, the diffusion CH4 flux at the depth of 5-10cm increased in all treatments, but the low total CH4 emission and increased CO2 emission. This study revealed that incorporation of organic matter into soil in conventional rice farming tended to increase CH4 emission. The main pathway of CH4 emission from rice paddy field was via rice, and it was influenced by tillage significantly. The decomposition of organic matter from rice straw and weeds incorporated into soil was the source of the bubble of CH4. Furthermore, it seemed that the most of diffusively transferred CH4 was easily oxidized to CO2.

Download Full-text

EFFECTS OF WATER PONDING ON DECREASING LEAF AND PANICLE TEMPERATURE IN RICE PADDY FIELDS

Jurnal Teknologi ◽

10.11113/jt.v76.5965 ◽

2015 ◽

Vol 76 (15) ◽

Cited By ~ 1

Author(s):

Yanyan Wang ◽

Hiroki Oue ◽

Sanz Grifrio Limin ◽

Sartika Laban

Keyword(s):

Relative Humidity ◽

Air Temperature ◽

Paddy Field ◽

Growing Season ◽

Rice Paddy ◽

Paddy Fields ◽

Flowering Stage ◽

Canopy Layer ◽

Relative Humidity Condition ◽

Rice Paddy Fields

Several studies have suggested the spikelet fertility would be significantly damaged if the air temperature (Ta) was high at heading and flowering stage. In this study, we evaluated the effect of water ponding in two paddy fields to decrease leaf temperature (Tl) and panicle temperature (Tp) during the 2014 growing season. Within the first conventionally water managed paddy field (cultivar Akitakomachi), we set 1 m × 1 m experiment plot (Plot A1) from July 8th to August 24th, and water was put in 15 cm depth in the morning at 8:30. For expecting larger difference of leaf and panicle temperature between in and outside the plot, the plot was expended to 2 m × 2 m (Plot A2) from August 25th to September 8th, 2014, and water was put in 15 cm depth at noon. This method was also used in the plot B (2 m ×2 m) which was installed in another conventionally water managed field (cultivar Nikomaru) from September 9th to 30th, 2014. Tl and Tp were measured every two or three hours during daytime in every 10 cm canopy layer in and outside plots. In the first experimental paddy field, at largest, Tl and Tp in the plot were 4.3 ℃, 5.5 ℃ lower than Tl and Tp outside the plot, respectively. Tp was 6.6 ℃ lower than Ta under low relative humidity condition. In the second experimental paddy field, Tl and Tp in the plot were 3.6 ℃, 3.4 ℃ lower than Tl and Tp outside the plot, respectively. It revealed water ponding was a useful method to decrease leaf and panicle temperature under larger solar radiation, higher air temperature and lower relative humidity conditions at heading and flowering stage.

Download Full-text

Urbanization dramatically altered the water balances of a paddy field dominated basin in Southern China

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-12-1941-2015 ◽

2015 ◽

Vol 12 (2) ◽

pp. 1941-1972 ◽

Cited By ~ 6

Author(s):

L. Hao ◽

G. Sun ◽

Y. Liu ◽

J. Wan ◽

M. Qin ◽

...

Keyword(s):

Paddy Field ◽

Land Surface ◽

Urban Areas ◽

Southern China ◽

Large Population ◽

Rice Paddy ◽

Paddy Fields ◽

Area Index ◽

Water Balances ◽

Rice Paddy Fields

Abstract. Rice paddy fields provide important ecosystem services (e.g., food production, water retention, carbon sequestration) to a large population globally. However, these benefits are declining as a result of rapid environmental and socioeconomic transformations characterized by population growth, urbanization, and climate change in many Asian countries. This case study examined the responses of streamflow and watershed water balances to the decline of rice paddy fields due to urbanization in the Qinhuai River Basin in southern China where massive industrialization has occurred in the region during the past three decades. We found that streamflow increased by 58% and evapotranspiration (ET) decreased by 23% during 1986–2013 as a result of an increase in urban areas of three folds and reduction of rice paddy field by 27%. Both highflows and lowflows increased significantly by about 28% from 2002 to 2013. The increases in streamflow were consistent with the decreases in ET and leaf area index monitored by independent remote sensing MODIS data. The reduction in ET and increase in streamflow was attributed to the large cropland conversion that overwhelmed the effects of regional climate warming and climate variability. Converting traditional rice paddy fields to urban use dramatically altered land surface conditions from a water-dominated to a human-dominated landscape, and thus was considered as one of the extreme types of contemporary hydrologic disturbances. The ongoing large-scale urbanization in the rice paddy-dominated regions in the humid southern China, and East Asia, will likely elevate stormflow volume, aggravate flood risks, and intensify urban heat island effects. Understanding the linkage between land use change and changes in hydrological processes is essential for better management of urbanizing watersheds.

Download Full-text

Functional soil organic matter fractions in response to long-term fertilizer management in a double-cropping paddy field of southern China

The Journal of Agricultural Science ◽

10.1017/s0021859621000125 ◽

2021 ◽

pp. 1-9

Author(s):

Haiming Tang ◽

Chao Li ◽

Lihong Shi ◽

Li Wen ◽

Kaikai Cheng ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Paddy Field ◽

Southern China ◽

Rice Paddy ◽

Chemical Fertilizer ◽

Protection Mechanism ◽

Rice Paddy Field ◽

Double Cropping

Abstract Soil organic matter (SOM) and its fractions play an important role in maintaining or improving soil quality and soil fertility. Therefore, the effects of a 34-year long-term fertilizer regime on six functional SOM fractions under a double-cropping rice paddy field of southern China were studied in the current paper. The field experiment included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM) and without fertilizer input as control (CK). The results showed that coarse unprotected particulate organic matter (cPOM), biochemically, physically–biochemically and chemically protected silt-sized fractions (NH-dSilt, NH-μSilt and H-dSilt) were the main carbon (C) storage fractions under long-term fertilization conditions, accounting for 16.7–26.5, 31.1–35.6, 16.2–17.3 and 7.5–8.2% of the total soil organic carbon (SOC) content in paddy soil, respectively. Compared with control, OM treatment increased the SOC content in the cPOM, fine unprotected POM fraction, pure physically protected fraction and physico-chemically protected fractions by 58.9, 106.7, 117.6 and 28.3%, respectively. The largest proportion of SOC to total SOC in the different fractions was biochemically protected, followed by chemically and unprotected, and physically protected were the smallest. These results suggested that a physical protection mechanism plays an important role in stabilizing C of paddy soil. In summary, the results showed that higher functional SOM fractions and physical protection mechanism play an important role in SOM cycling in terms of C sequestration under the double-cropping rice paddy field.

Download Full-text