scholarly journals Sources of atmospheric methane: Measurements in rice paddies and a discussion

1981 ◽  
Vol 86 (C8) ◽  
pp. 7203 ◽  
Author(s):  
Ralph J. Cicerone ◽  
James D. Shetter
Keyword(s):  
Atmospheric Methane ◽  
Rice Paddies

scholarly journals Sensitivity of wetland methane emissions to model assumptions: application and model testing against site observations

2012 ◽  
Vol 9 (7) ◽  
pp. 2793-2819 ◽  
Author(s):  
L. Meng ◽  
P. G. M. Hess ◽  
N. M. Mahowald ◽  
J. B. Yavitt ◽  
W. J. Riley ◽  
...  
Keyword(s):  
Soil Ph ◽  
High Latitude ◽  
Large Range ◽  
Rice Paddy ◽  
Temporal Variations ◽  
Methane Emissions ◽  
Biogeochemical Model ◽  
Atmospheric Methane ◽  
Rice Paddies ◽  
Community Land Model

Abstract. Methane emissions from natural wetlands and rice paddies constitute a large proportion of atmospheric methane, but the magnitude and year-to-year variation of these methane sources are still unpredictable. Here we describe and evaluate the integration of a methane biogeochemical model (CLM4Me; Riley et al., 2011) into the Community Land Model 4.0 (CLM4CN) in order to better explain spatial and temporal variations in methane emissions. We test new functions for soil pH and redox potential that impact microbial methane production in soils. We also constrain aerenchyma in plants in always-inundated areas in order to better represent wetland vegetation. Satellite inundated fraction is explicitly prescribed in the model, because there are large differences between simulated fractional inundation and satellite observations, and thus we do not use CLM4-simulated hydrology to predict inundated areas. A rice paddy module is also incorporated into the model, where the fraction of land used for rice production is explicitly prescribed. The model is evaluated at the site level with vegetation cover and water table prescribed from measurements. Explicit site level evaluations of simulated methane emissions are quite different than evaluating the grid-cell averaged emissions against available measurements. Using a baseline set of parameter values, our model-estimated average global wetland emissions for the period 1993–2004 were 256 Tg CH4 yr−1 (including the soil sink) and rice paddy emissions in the year 2000 were 42 Tg CH4 yr−1. Tropical wetlands contributed 201 Tg CH4 yr−1, or 78% of the global wetland flux. Northern latitude (>50 N) systems contributed 12 Tg CH4 yr−1. However, sensitivity studies show a large range (150–346 Tg CH4 yr−1) in predicted global methane emissions (excluding emissions from rice paddies). The large range is sensitive to (1) the amount of methane transported through aerenchyma, (2) soil pH (±100 Tg CH4 yr−1), and (3) redox inhibition (±45 Tg CH4 yr−1). Results are sensitive to biases in the CLMCN and to errors in the satellite inundation fraction. In particular, the high latitude methane emission estimate may be biased low due to both underestimates in the high-latitude inundated area captured by satellites and unrealistically low high-latitude productivity and soil carbon predicted by CLM4.

scholarly journals Fingerprint of rice paddies in spatial–temporal dynamics of atmospheric methane concentration in monsoon Asia

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Geli Zhang ◽  
Xiangming Xiao ◽  
Jinwei Dong ◽  
Fengfei Xin ◽  
Yao Zhang ◽  
...  
Keyword(s):  
Methane Concentration ◽  
Temporal Dynamics ◽  
Atmospheric Methane ◽  
Rice Paddies ◽  
Monsoon Asia

NUMERICAL MODEL ON METHANE EMISSIONS FROM AGRICULTURE SECTOR

2020 ◽  
Vol 02 (01) ◽  
pp. 2050003
Author(s):  
J. B. SHUKLA ◽  
SHYAM SUNDAR ◽  
ASHISH KUMAR MISHRA ◽  
RAM NARESH
Keyword(s):  
Numerical Simulation ◽  
Growth Rate ◽  
Global Warming ◽  
Logistic Models ◽  
Atmospheric Temperature ◽  
Atmospheric Methane ◽  
Rice Paddies ◽  
Atmospheric Concentration ◽  
Agriculture Sector ◽  
Equilibrium Level

Atmospheric methane, emitted from agriculture sector such as production of rice paddies and farming of livestock populations, is one of the important factors responsible for increasing the average atmospheric temperature leading to global warming. It is, therefore, crucial to comprehend the dynamics of methane emission and its effect on global warming. In this paper, a nonlinear mathematical model is proposed and analyzed to study the increase of average atmospheric temperature (or average global warming temperature) caused by emission of methane due to various processes involved in the production of rice paddies and farming of livestock populations simultaneously. In the modeling process, six variables are considered, namely, the cumulative biomass density of rice paddies, the cumulative density of livestock populations, the cumulative density of methane formed by various processes involved in the production of rice paddies, the cumulative density of methane formed by various processes involved in the farming of livestock populations, the atmospheric concentration of methane and the average atmospheric temperature. It is assumed that both the cumulative biomass densities of rice paddies and livestock populations follow logistic models with their respective growth rates and carrying capacities. The growth rate of concentration of methane in the atmosphere is assumed to be directly proportional to the cumulative densities of various processes involved in the production of rice paddies as well as in the farming of livestock populations. This growth rate also increases with a constant rate from various natural sources such as wetlands, etc. The growth rate of average global warming temperature is assumed to be proportional to the increased level of methane concentration in the atmosphere from its equilibrium value. It is also assumed that this temperature decreases with a rate proportional to its enhanced level from its equilibrium level caused by various natural factors such as rain fall, snowfall, etc. The proposed model is analyzed using the stability theory of differential equations and numerical simulation. The analysis shows that as the emission of methane from various processes involved in the production of rice paddies and farming of livestock populations increase, the average global warming temperature increases considerably from its equilibrium level. The numerical simulation of the model confirms the analytical results.

Measurements of atmospheric methane at the Japanese Antarctic Station, Syowa

Tellus B ◽  
1992 ◽  
Vol 44 (4) ◽  
pp. 273-281 ◽  
Author(s):  
Shuhji Aoki ◽  
Takakiyo Nakazawa ◽  
Shohei Murayama ◽  
Sadao Kawaguchi
Keyword(s):  
Atmospheric Methane

Phytoremediation of Atmospheric Methane

2013 ◽  
Author(s):  
Stuart Strand ◽  
Neil Bruce ◽  
Liz Rylott ◽  
Long Zhang
Keyword(s):  
Atmospheric Methane

scholarly journals Evaluation of Seasonal Groundwater Quality Changes Associated with Groundwater Pumping and Level Fluctuations in an Agricultural Area, Korea

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 51
Author(s):  
Kyoochul Ha ◽  
Eunhee Lee ◽  
Hyowon An ◽  
Sunghyun Kim ◽  
Changhui Park ◽  
...  
Keyword(s):  
Water Quality ◽  
Groundwater Quality ◽  
Groundwater Level ◽  
Irrigation Water ◽  
Agricultural Area ◽  
Water Type ◽  
Quality Changes ◽  
Groundwater Pumping ◽  
Rice Paddies ◽  
Groundwater Levels

This study was conducted to evaluate seasonal groundwater quality due to groundwater pumping and hydrochemical characteristics with groundwater level fluctuations in an agricultural area in Korea. Groundwater levels were observed for about one year using automatic monitoring sensors, and groundwater uses were estimated based on the monitoring data. Groundwater use in the area is closely related to irrigation for rice farming, and rising groundwater levels occur during the pumping, which may be caused by the irrigation water of rice paddies. Hydrochemical analysis results for two separate times (17 July and 1 October 2019) show that the dissolved components in groundwater decreased overall due to dilution, especially at wells in the alluvial aquifer and shallow depth. More than 50% of the samples were classified as CaHCO3 water type, and changes in water type occurred depending on the well location. Water quality changes were small at most wells, but changes at some wells were evident. In addition, the groundwater quality was confirmed to have the effect of saltwater supplied during the 2018 drought by comparison with seawater. According to principal component analysis (PCA), the water quality from July to October was confirmed to have changed due to dilution, and the effect was strong at shallow wells. In the study areas where rice paddy farming is active in summer, irrigation water may be one of the important factors changing the groundwater quality. These results provide a qualitative and quantitative basis for groundwater quality change in agricultural areas, particularly rice paddies areas, along with groundwater level and usage.

scholarly journals A nature-based negative emissions technology able to remove atmospheric methane and other greenhouse gases

2021 ◽  
Author(s):  
Tingzhen Ming ◽  
Renaud de Richter ◽  
Franz Dietrich Oeste ◽  
Robert Tulip ◽  
Sylvain Caillol
Keyword(s):  
Greenhouse Gases ◽  
Atmospheric Methane ◽  
Negative Emissions

scholarly journals Effects of novel bioorganic fertilizer application on soil enzymes and bacterial community in multi-site rice paddies in China

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zuren Li ◽  
Jincai Han ◽  
Haodong Bai ◽  
Di Peng ◽  
Lifeng Wang ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Field Experiments ◽  
Chemical Properties ◽  
Soil Bacterial Community ◽  
General Function ◽  
Rice Paddies ◽  
Phylogenetic Groups ◽  
Total N ◽  
Bioorganic Fertilizer ◽  
Soil Bacterial

AbstractApplication of a novel bioorganic fertilizer (BIO) has been effectively used to inhibit weeds in rice paddies. To identify changes in soil bacterial community and enzymes in response to BIO treatments, field experiments were carried out in five major rice-growing areas in China. The dominant phylogenetic groups recorded included Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Acidobacteria. Anaeromyxobacter, Bacteroides, Bifidobacterium, Escherichia- Shigella, Geobacter and Haliangium were significantly different between BIO-treatment and untreated control and aided in general function (R), amino acid transport, metabolism (E) and transcription (K) clusters. The soil chemical properties and enzyme activities were less affected by BIO at these study sites. RDA analysis showed that soil bacterial community had a significant positive correlations among northern latitude, eastern longitude, exchangeable K, total K, total P, soil pH, and total N, except for organic matter, hydrolytic N and extractable P. Overall, our work showed that application of BIO does not alter the main community structure and functional diversity of soil bacteria in rice paddies and should be encouraged for use as a sustainable weed management strategy.

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