Modelling Methane and Nitrous Oxide Emissions from Rice Paddy Wetlands in India Using Artificial Neural Networks (ANNs)

Paddy fields, which are shallow man-made wetlands, are estimated to be responsible for ~11% of the total methane emissions attributed to anthropogenic sources. The role of water use in driving these emissions, and the apportioning of the emissions to individual countries engaged in paddy cultivation, are aspects that have been mired in controversy and disagreement. This is largely due to the fact that methane (CH4) emissions not only change with the cultivar type but also regions, climate, soil type, soil conditions, manner of irrigation, type and quantity of fertilizer added—to name a few. The factors which can influence these aspects also encompass a wide range, and have origins in causes which can be physical, chemical, biological, and combinations of these. Exceedingly complex feedback mechanisms, exerting different magnitudes and types of influences on CH4 emissions under different conditions, are operative. Similar is the case of nitrous oxide (N2O); indeed, the present level of understanding of the factors which influence the quantum of its emission is still more patchy. This makes it difficult to even understand precisely the role of the myriad factors, less so model them. The challenge is made even more daunting by the fact that accurate and precise data on most of these aspects is lacking. This makes it nearly impossible to develop analytical models linking causes with effects vis a vis CH4 and N2O emissions from paddy fields. For situations like this the bioinspired artificial intelligence technique of artificial neural network (ANN), which can model a phenomenon on the basis of past data and without the explicit understanding of the mechanism phenomena, may prove useful. However, no such model for CH4 or N2O has been developed so far. Hence the present work was undertaken. It describes ANN-based models developed by us to predict CH4 and N2O emissions using soil characteristics, fertilizer inputs, and rice cultivar yield as inputs. Upon testing the predictive ability of the models with sets of data not used in model development, it was seen that there was excellent agreement between model forecasts and experimental findings, leading to correlations coefficients of 0.991 and 0.96, and root mean square error (RMSE) of 11.17 and 261.3, respectively, for CH4 and N2O emissions. Thus, the models can be used to estimate CH4 and N2O emissions from all those continuously flooded paddy wetlands for which data on total organic carbon, soil electrical conductivity, applied nitrogen, phosphorous and potassium, NPK, and grain yield is available.

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Assessing Seasonal Methane and Nitrous Oxide Emissions from Furrow-Irrigated Rice with Cover Crops

Agriculture ◽

10.3390/agriculture11030261 ◽

2021 ◽

Vol 11 (3) ◽

pp. 261

Author(s):

Sandhya Karki ◽

M. Arlene A. Adviento-Borbe ◽

Joseph H. Massey ◽

Michele L. Reba

Keyword(s):

Nitrous Oxide ◽

Cover Crops ◽

Management Practices ◽

Irrigation Management ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Irrigated Rice ◽

Cereal Rye ◽

Ch4 Emissions ◽

Ch4 And N2o

Improved irrigation management is identified as a potential mitigation option for methane (CH4) emissions from rice (Oryza sativa). Furrow-irrigated rice (FR), an alternative method to grow rice, is increasingly adopted in the Mid-South U.S. However, FR may provide a potential risk to yield performance and higher emissions of nitrous oxide (N2O). This study quantified the grain yields, CH4 and N2O emissions from three different water management practices in rice: multiple-inlet rice irrigation (MIRI), FR, and FR with cereal rye (Secale cereale) and barley (Hordeum vulgare) as preceding winter cover crops (FRCC). CH4 and N2O fluxes were measured from May to September 2019 using a static chamber technique. Grain yield from FR (11.8 Mg ha−1) and MIRI (12.0 Mg ha−1) was similar, and significantly higher than FRCC (8.5 Mg ha−1). FR and FRCC drastically reduced CH4 emissions compared to MIRI. Total seasonal CH4 emissions decreased in the order of 44 > 11 > 3 kg CH4-C ha−1 from MIRI, FR, and FRCC, respectively. Cumulative seasonal N2O emissions were low from MIRI (0.1 kg N2O-N ha−1) but significantly higher from FR (4.4 kg N2O-N ha−1) and FRCC (3.0 kg N2O-N ha−1). However, there was no net difference in global warming potential among FR, FRCC and MIRI. These results suggest that the increased N2O flux from furrow-irrigated rice may not greatly detract from the potential benefits that furrow-irrigation offers rice producers.

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Quantifying methane and nitrous oxide emissions from the UK and Ireland using a national-scale monitoring network

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-6393-2015 ◽

2015 ◽

Vol 15 (11) ◽

pp. 6393-6406 ◽

Cited By ~ 30

Author(s):

A. L. Ganesan ◽

A. J. Manning ◽

A. Grant ◽

D. Young ◽

D .E. Oram ◽

...

Keyword(s):

Nitrous Oxide ◽

Transport Model ◽

Anthropogenic Sources ◽

Nitrous Oxide Emissions ◽

Environmental Drivers ◽

N2o Emissions ◽

Hierarchical Bayesian ◽

Model Errors ◽

Ch4 Emissions ◽

The Uk

Abstract. The UK is one of several countries around the world that has enacted legislation to reduce its greenhouse gas emissions. In this study, we present top-down emissions of methane (CH4) and nitrous oxide (N2O) for the UK and Ireland over the period August~2012 to August~2014. These emissions were inferred using measurements from a network of four sites around the two countries. We used a hierarchical Bayesian inverse framework to infer fluxes as well as a set of covariance parameters that describe uncertainties in the system. We inferred average UK total emissions of 2.09 (1.65–2.67) Tg yr−1 CH4 and 0.101 (0.068–0.150) Tg yr−1 N2O and found our derived UK estimates to be generally lower than the a priori emissions, which consisted primarily of anthropogenic sources and with a smaller contribution from natural sources. We used sectoral distributions from the UK National Atmospheric Emissions Inventory (NAEI) to determine whether these discrepancies can be attributed to specific source sectors. Because of the distinct distributions of the two dominant CH4 emissions sectors in the UK, agriculture and waste, we found that the inventory may be overestimated in agricultural CH4 emissions. We found that annual mean N2O emissions were consistent with both the prior and the anthropogenic inventory but we derived a significant seasonal cycle in emissions. This seasonality is likely due to seasonality in fertilizer application and in environmental drivers such as temperature and rainfall, which are not reflected in the annual resolution inventory. Through the hierarchical Bayesian inverse framework, we quantified uncertainty covariance parameters and emphasized their importance for high-resolution emissions estimation. We inferred average model errors of approximately 20 and 0.4 ppb and correlation timescales of 1.0 (0.72–1.43) and 2.6 (1.9–3.9) days for CH4 and N2O, respectively. These errors are a combination of transport model errors as well as errors due to unresolved emissions processes in the inventory. We found the largest CH4 errors at the Tacolneston station in eastern England, which may be due to sporadic emissions from landfills and offshore gas in the North Sea.

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Spatial and temporal variability of nitrous oxide emissions in a mixed farming landscape of Denmark

Biogeosciences ◽

10.5194/bg-9-2989-2012 ◽

2012 ◽

Vol 9 (8) ◽

pp. 2989-3002 ◽

Cited By ~ 18

Author(s):

K. Schelde ◽

P. Cellier ◽

T. Bertolini ◽

T. Dalgaard ◽

T. Weidinger ◽

...

Keyword(s):

Land Use ◽

Nitrous Oxide ◽

Agricultural Land ◽

Nitrous Oxide Emissions ◽

Soil Conditions ◽

Spatial And Temporal Variability ◽

N2o Emissions ◽

N2o Production ◽

Mixed Farming ◽

N2o Fluxes

Abstract. Nitrous oxide (N2O) emissions from agricultural land are variable at the landscape scale due to variability in land use, management, soil type, and topography. A field experiment was carried out in a typical mixed farming landscape in Denmark, to investigate the main drivers of variations in N2O emissions, measured using static chambers. Measurements were made over a period of 20 months, and sampling was intensified during two weeks in spring 2009 when chambers were installed at ten locations or fields to cover different crops and topography and slurry was applied to three of the fields. N2O emissions during spring 2009 were relatively low, with maximum values below 20 ng N m−2 s−1. This applied to all land use types including winter grain crops, grasslands, meadows, and wetlands. Slurry application to wheat fields resulted in short-lived two-fold increases in emissions. The moderate N2O fluxes and their moderate response to slurry application were attributed to dry soil conditions due to the absence of rain during the four previous weeks. Cumulative annual emissions from two arable fields that were both fertilized with mineral fertilizer and manure were large (17 kg N2O-N ha−1 yr−1 and 5.5 kg N2O-N ha−1 yr−1) during the previous year when soil water conditions were favourable for N2O production during the first month following fertilizer application. Our findings confirm the importance of weather conditions as well as nitrogen management on N2O fluxes.

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Response of Methane and Nitrous Oxide Emissions from Peatlands to Permafrost Thawing in Xiaoxing’an Mountains, Northeast China

Atmosphere ◽

10.3390/atmos12020222 ◽

2021 ◽

Vol 12 (2) ◽

pp. 222

Author(s):

Xiaoxin Sun ◽

Hongjun Wang ◽

Changchun Song ◽

Xin Jin ◽

Curtis J. Richardson ◽

...

Keyword(s):

Northeast China ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Ch4 Emissions ◽

Growing Seasons ◽

Xiaoxing’An Mountains ◽

Thawing Permafrost ◽

Ch4 And N2o ◽

And Shifts ◽

Permafrost Thawing

Permafrost thawing may lead to the release of carbon and nitrogen in high-latitude regions of the Northern Hemisphere, mainly in the form of greenhouse gases. Our research aims to reveal the effects of permafrost thawing on CH4 and N2O emissions from peatlands in Xiaoxing’an Mountains, Northeast China. During four growing seasons (2011–2014), in situ CH4 and N2O emissions were monitored from peatland under permafrost no-thawing, mild-thawing, and severe-thawing conditions in the middle of the Xiaoxing’an Mountains by a static-chamber method. Average CH4 emissions in the severe-thawing site were 55-fold higher than those in the no-thawing site. The seasonal variation of CH4 emission became more aggravated with the intensification of permafrost thawing, in which the emission peaks became larger and the absorption decreased to zero. The increased CH4 emissions were caused by the expansion of the thawing layer and the subsequent increases in soil temperature, water table, and shifts of plant communities. However, N2O emissions did not change with thawing. Permafrost thawing increased CH4 emissions but did not impact N2O emissions in peatlands in the Xiaoxing’an Mountains. Increased CH4 emissions from peatlands in this region may amplify global warming.

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Effect of volume of urine and mass of faeces on N2O and CH4 emissions of dairy-cow excreta in a tropical pasture

Animal Production Science ◽

10.1071/an15392 ◽

2018 ◽

Vol 58 (6) ◽

pp. 1079 ◽

Cited By ~ 11

Author(s):

Abmael da Silva Cardoso ◽

Bruno José Rodrigues Alves ◽

Segundo Urquiaga ◽

Robert Michael Boddey

Keyword(s):

Nitrous Oxide ◽

Dairy Cows ◽

Dairy Cow ◽

Emission Factor ◽

N2o Emissions ◽

Tropical Pasture ◽

Ch4 Emissions ◽

Ch4 And N2o

We aimed to quantify nitrous oxide (N2O) and methane (CH4) emissions as a function of the addition of different quantities of bovine faeces and urine on soil under pasture. Two experiments were performed in randomised complete blocks with five replicates. In the first experiment, the emissions of CH4 and N2O were evaluated for 14 days after the addition of four amounts of faeces (0.0, 1.2, 1.8 and 2.4 kg of fresh faeces per plot), and in a second experiment, N2O emissions were evaluated for 43 days after addition of four volumes of urine (0.0, 1.0, 1.5 and 2.0 L). Urine and faeces came from crossbred (Fresian × Gir) dairy cows fed on pasture and concentrates. N2O emissions from faeces did not alter the emission factor (EF) according to the faeces weight (P = 0.73). N2O-N EF from faeces-N averaged 0.18% (±0.05) of total applied N. The volume of urine applied influenced N2O losses. The EF decreased linearly (P = 0.015) with increasing volumes of urine, being 4.9% (±0.75), 3.36% (±0.7) and 2.43% (±0.46) of N applied emitted as N2O for the 1.0, 1.5 and 2.0 L volumes of urine respectively. The EF from urine was significantly (P < 0.0001) higher than the EF from faeces. There was no change to the CH4 emissions per kilogram of excreta when the amount of faeces added was varied (P = 0.87). However, the CH4 emitted increased linearly with the amount of faeces (P = 0.02). The CH4 EF was estimated to be 0.95 (±0.38) kg/head.year.

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Investigating the Influence of Biochar Particle Size and Depth of Placement on Nitrous Oxide (N2O) Emissions from Simulated Urine Patches

Agriculture ◽

10.3390/agriculture8110175 ◽

2018 ◽

Vol 8 (11) ◽

pp. 175

Author(s):

Ainul Mahmud ◽

Marta Camps-Arbestain ◽

Mike Hedley

Keyword(s):

Particle Size ◽

Nitrous Oxide ◽

Soil Column ◽

Soil Layer ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Top Soil ◽

The Impact ◽

Soil Inversion

The use of biochar reduces nitrous oxide (N2O) emissions from soils under specific conditions yet the mechanisms through which interactions occur are not fully understood. The objectives of this glasshouse study were to investigate the effect of (i) biochar particle size, and (ii) the impact of soil inversion—through simulated mouldboard ploughing—on N2O emissions from soils to which cattle urine was applied. Pine biochar (550 °C) with two different particle sizes (<2 mm and >4 mm) was mixed either into the top soil layer at the original 0–10 cm depth in the soil column or at 10–20 cm depth by inverting the top soil to simulate ploughing. Nitrous oxide emissions were monitored for every two to three days, up to seven weeks during the summer trial and measurements were repeated during the autumn trial. We found that the use of large particle size biochar in the inverted soil had significant impact on increasing the cumulative N2O emissions in autumn trial, possibly through changes in the water hydraulic conductivity of the soil column and increased water retention at the boundary between soil layers. This study thus highlights the importance of the role of biochar particle size and the method of biochar placement on soil physical properties and the implications of these on N2O emissions.

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PSXI-25 The effect of plant tannins on methane and nitrous oxide emissions from dairy manure under laboratory conditions

Journal of Animal Science ◽

10.1093/jas/skaa278.681 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 387-387

Author(s):

Byeng Ryel Min ◽

David Parker ◽

Kenneth Casey ◽

Will Willis ◽

Lana Castleberry ◽

...

Keyword(s):

Nitrous Oxide ◽

Global Climate ◽

Redox Status ◽

Dairy Manure ◽

Nitrous Oxide Emissions ◽

Control Group ◽

N2o Emissions ◽

Sample Collection ◽

Ch4 And N2o

Abstract Emissions of greenhouse gases (GHG; methane, CH4; nitrous oxide, N2O) from dairy cattle manure contribute to global climate change. The aim of this study was to assess the associative effects of three different levels [0, 4 and 8% wet weight (WW) basis] of condensed tannins (CT; quebracho tannins) and hydrolysable tannins (HT; chestnut tannins) on CH4 and N2O emissions. The dairy manure consisted of a 50:50 volume mixture of fresh feces and dry manure scraped from the surface of an open-lot dairy in the Texas panhandle. Control (0% tannin), 4%, and 8% of CT or HT (w/w) were added to each bucket and homogenized with a hand mixer for 5 min. Aliquots of 220 g (WW) manure, with or without tannins, were placed into 1 L fermentation bottles (n = 3, total of 18 bottles) and incubated at 39o C for 14 days. A second set of 18 fermenters were set up in the same manner for sample collection at 0, 2, 3, 6, and 9 h to discern changes in pH and redox status. There were no differences in redox values with the addition of either tannin type to in vitro fermenters. However, application of CT to dairy manure reduced (P < 0.05-0.01) cumulative CH4 emissions by 68 to 63% at the concentrations of 4 and 8% WW, respectively, compared with the non-tannin control group. Both CT and HT decreased cumulative N2O emissions (P < 0.02). Examination of the emission kinetics revealed a tradeoff (interchange or pollution swapping) between CH4 and N2O emissions when tannins were applied to manure. These results suggested that the inclusion of 4% CT (WW) is a promising technique for reducing CH4 and N2O emissions from excreted dairy manure. Further study is warranted to investigate the effects of feeding CT and HT on manure-derived GHG in dairy systems.

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Biochar and urease inhibitor mitigate NH3 and N2O emissions and improve wheat yield in a urea fertilized alkaline soil

Scientific Reports ◽

10.1038/s41598-021-96771-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Khadim Dawar ◽

Shah Fahad ◽

M. M. R. Jahangir ◽

Iqbal Munir ◽

Syed Sartaj Alam ◽

...

Keyword(s):

Nitrous Oxide ◽

Grain Yield ◽

Block Design ◽

N Uptake ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Urease Inhibitor ◽

Alkaline Soil ◽

Total N ◽

N Assimilation

AbstractIn this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH3) and nitrous oxide (N2O) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha−1), BC (10 Mg ha−1), urea + BC and urea + BC + UI (1 L ton−1)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH3 emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH3 and N2O emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.

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Nitrous Oxide Emissions in Pineapple Cultivation on a Tropical Peat Soil

Sustainability ◽

10.3390/su13094928 ◽

2021 ◽

Vol 13 (9) ◽

pp. 4928

Author(s):

Alicia Vanessa Jeffary ◽

Osumanu Haruna Ahmed ◽

Roland Kueh Jui Heng ◽

Liza Nuriati Lim Kim Choo ◽

Latifah Omar ◽

...

Keyword(s):

Nitrous Oxide ◽

Soil Temperature ◽

Peat Soil ◽

Farming Systems ◽

N2o Emission ◽

Nitrous Oxide Emissions ◽

Natural State ◽

N2o Emissions ◽

Wet Season ◽

Peat Soils

Farming systems on peat soils are novel, considering the complexities of these organic soil. Since peat soils effectively capture greenhouse gases in their natural state, cultivating peat soils with annual or perennial crops such as pineapples necessitates the monitoring of nitrous oxide (N2O) emissions, especially from cultivated peat lands, due to a lack of data on N2O emissions. An on-farm experiment was carried out to determine the movement of N2O in pineapple production on peat soil. Additionally, the experiment was carried out to determine if the peat soil temperature and the N2O emissions were related. The chamber method was used to capture the N2O fluxes daily (for dry and wet seasons) after which gas chromatography was used to determine N2O followed by expressing the emission of this gas in t ha−1 yr−1. The movement of N2O horizontally (832 t N2O ha−1 yr−1) during the dry period was higher than in the wet period (599 t N2O ha−1 yr−1) because of C and N substrate in the peat soil, in addition to the fertilizer used in fertilizing the pineapple plants. The vertical movement of N2O (44 t N2O ha−1 yr−1) was higher in the dry season relative to N2O emission (38 t N2O ha−1 yr−1) during the wet season because of nitrification and denitrification of N fertilizer. The peat soil temperature did not affect the direction (horizontal and vertical) of the N2O emission, suggesting that these factors are not related. Therefore, it can be concluded that N2O movement in peat soils under pineapple cultivation on peat lands occurs horizontally and vertically, regardless of season, and there is a need to ensure minimum tilling of the cultivated peat soils to prevent them from being an N2O source instead of an N2O sink.

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Pineapple Residue Ash Reduces Carbon Dioxide and Nitrous Oxide Emissions in Pineapple Cultivation on Tropical Peat Soils at Saratok, Malaysia

Sustainability ◽

10.3390/su13031014 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1014

Author(s):

Liza Nuriati Lim Kim Choo ◽

Osumanu Haruna Ahmed ◽

Nik Muhamad Nik Majid ◽

Zakry Fitri Abd Aziz

Keyword(s):

Carbon Dioxide ◽

Nitrous Oxide ◽

Peat Soil ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Peat Soils ◽

Closed Chamber ◽

Npk Fertilizers ◽

Npk Fertilizer ◽

Carbon Dioxide Co2

Burning pineapple residues on peat soils before pineapple replanting raises concerns on hazards of peat fires. A study was conducted to determine whether ash produced from pineapple residues could be used to minimize carbon dioxide (CO2) and nitrous oxide (N2O) emissions in cultivated tropical peatlands. The effects of pineapple residue ash fertilization on CO2 and N2O emissions from a peat soil grown with pineapple were determined using closed chamber method with the following treatments: (i) 25, 50, 70, and 100% of the suggested rate of pineapple residue ash + NPK fertilizer, (ii) NPK fertilizer, and (iii) peat soil only. Soils treated with pineapple residue ash (25%) decreased CO2 and N2O emissions relative to soils without ash due to adsorption of organic compounds, ammonium, and nitrate ions onto the charged surface of ash through hydrogen bonding. The ability of the ash to maintain higher soil pH during pineapple growth primarily contributed to low CO2 and N2O emissions. Co-application of pineapple residue ash and compound NPK fertilizer also improves soil ammonium and nitrate availability, and fruit quality of pineapples. Compound NPK fertilizers can be amended with pineapple residue ash to minimize CO2 and N2O emissions without reducing peat soil and pineapple productivity.

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