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

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 261
Author(s):  
Sandhya Karki ◽  
M. Arlene A. Adviento-Borbe ◽  
Joseph H. Massey ◽  
Michele L. Reba

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.

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2169 ◽  
Author(s):  
Tabassum Abbasi ◽  
Tasneem Abbasi ◽  
Chirchom Luithui ◽  
Shahid Abbas Abbasi

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.


Soil Research ◽  
2020 ◽  
Vol 58 (3) ◽  
pp. 238
Author(s):  
Terry J. Rose ◽  
Lee J. Kearney ◽  
Stephen Morris ◽  
Lukas Van Zwieten

The integration of legumes into coppiced tree crop systems to replace some or all of the external nitrogen (N) fertiliser requirements may be one means to lower seasonal nitrous oxide (N2O) emissions. We investigated soil N2O emissions using static chamber methodology in field trials located within two commercial tea tree (Melaleuca alternifolia) plantations (Casino and Tweed Heads) where N (116 and 132 kg N ha–1 respectively) was supplied via poultry litter application (5 t wet ha–1) or by termination of annual legumes (soybean or mung bean) grown in the inter-row. While there was no treatment effect at the Tweed Heads site, both legume treatments had significantly (P = 0.01) lower cumulative N2O emissions (0.33 and 0.30 kg N2O-N ha–1 season–1 for soybean and mung beans respectively) than the poultry litter treatment (0.66 kg N2O-N ha–1 season–1) at the Casino site. However, the amount of N added to soils in each treatment was not identical owing to an inability to accurately predict N inputs by legume crops, and thus differences could not be attributed to the N source. A third site was thus established at Leeville comparing N2O emissions from poultry litter amendment (5 t wet ha–1 contributing 161 kg N ha–1) to an inter-row faba bean crop (contributing 92 kg N ha–1) and a nil-N control. Cumulative seasonal N2O emissions were significantly (P < 0.05) lower in the faba bean treatment than the poultry litter treatment (0.08 and 0.23 kg N2O-N ha–1 season–1 respectively), but owing to different N inputs and generally low emissions, it was not possible to draw definitive conclusions on whether green manure legume crops can lower N2O emissions. Overall, soil N2O emissions in coppiced tea tree systems under current management practices were very low, offering limited potential to reduce seasonal N2O emissions through management practice change.


Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 222
Author(s):  
Xiaoxin Sun ◽  
Hongjun Wang ◽  
Changchun Song ◽  
Xin Jin ◽  
Curtis J. Richardson ◽  
...  

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.


2018 ◽  
Vol 58 (6) ◽  
pp. 1079 ◽  
Author(s):  
Abmael da Silva Cardoso ◽  
Bruno José Rodrigues Alves ◽  
Segundo Urquiaga ◽  
Robert Michael Boddey

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.


2013 ◽  
Vol 43 (3) ◽  
pp. 322-338 ◽  
Author(s):  
Diana Signor ◽  
Carlos Eduardo Pellegrino Cerri

The greenhouse gases concentration in the atmosphere have significantly increased since the beginning of the Industrial Revolution. The most important greenhouse gases are CO2, CH4 and N2O, with CH4 and N2O presenting global warming potentials 25 and 298 times higher than CO2, respectively. Most of the N2O emissions take place in soils and are related with agricultural activities. So, this review article aimed at presenting the mechanisms of N2O formation and emission in agricultural soils, as well as gathering and discussing information on how soil management practices may be used to reduce such emissions. The N2O formation in the soil occurs mainly through nitrification and denitrification processes, which are influenced by soil moisture, temperature, oxygen concentration, amount of available organic carbon and nitrogen and soil C/N ratio. Among these factors, those related to soil could be easily altered by management practices. Therefore, understanding the processes of N2O formation in soils and the factors influencing these emissions is fundamental to develop efficient strategies to reduce N2O emissions in agricultural soils.


2015 ◽  
Vol 15 (11) ◽  
pp. 6393-6406 ◽  
Author(s):  
A. L. Ganesan ◽  
A. J. Manning ◽  
A. Grant ◽  
D. Young ◽  
D .E. Oram ◽  
...  

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.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 387-387
Author(s):  
Byeng Ryel Min ◽  
David Parker ◽  
Kenneth Casey ◽  
Will Willis ◽  
Lana Castleberry ◽  
...  

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 &lt; 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 &lt; 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.


Soil Systems ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 20 ◽  
Author(s):  
Anish Sapkota ◽  
Amir Haghverdi ◽  
Claudia C. E. Avila ◽  
Samantha C. Ying

Irrigation practices can greatly influence greenhouse gas (GHG) emissions because of their control on soil microbial activity and substrate supply. However, the effects of different irrigation management practices, such as flood irrigations versus reduced volume methods, including drip and sprinkler irrigation, on GHG emissions are still poorly understood. Therefore, this review was performed to investigate the effects of different irrigation management strategies on the emission of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) by synthesizing existing research that either directly or indirectly examined the effects of at least two irrigation rates on GHG emissions within a single field-based study. Out of thirty-two articles selected for review, reduced irrigation was found to be effective in lowering the rate of CH4 emissions, while flood irrigation had the highest CH4 emission. The rate of CO2 emission increased mostly under low irrigation, and the effect of irrigation strategies on N2O emissions were inconsistent, though a majority of studies reported low N2O emissions in continuously flooded field treatments. The global warming potential (GWP) demonstrated that reduced or water-saving irrigation strategies have the potential to decrease the effect of GHG emissions. In general, GWP was higher for the field that was continuously flooded. The major finding from this review is that optimizing irrigation may help to reduce CH4 emissions and net GWP. However, more field research assessing the effect of varying rates of irrigation on the emission of GHGs from the agricultural field is warranted.


Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 659 ◽  
Author(s):  
Henrike Mielenz ◽  
Peter J. Thorburn ◽  
Robert H. Harris ◽  
Sally J. Officer ◽  
Guangdi Li ◽  
...  

Nitrous oxide (N2O) emissions from Australian grain cropping systems are highly variable due to the large variations in soil and climate conditions and management practices under which crops are grown. Agricultural soils contribute 55% of national N2O emissions, and therefore mitigation of these emissions is important. In the present study, we explored N2O emissions, yield and emissions intensity in a range of management practices in grain crops across eastern Australia with the Agricultural Production Systems sIMulator (APSIM). The model was initially evaluated against experiments conducted at six field sites across major grain-growing regions in eastern Australia. Measured yields for all crops used in the experiments (wheat, barley, sorghum, maize, cotton, canola and chickpea) and seasonal N2O emissions were satisfactorily predicted with R2=0.93 and R2=0.91 respectively. As expected, N2O emissions and emissions intensity increased with increasing nitrogen (N) fertiliser input, whereas crop yields increased until a yield plateau was reached at a site- and crop-specific N rate. The mitigation potential of splitting N fertiliser application depended on the climate conditions and was found to be relevant only in the southern grain-growing region, where most rainfall occurs during the cropping season. Growing grain legumes in rotation with cereal crops has great potential to reduce mineral N fertiliser requirements and so N2O emissions. In general, N management strategies that maximise yields and increase N use efficiency showed the greatest promise for N2O mitigation.


2002 ◽  
Vol 82 (3) ◽  
pp. 365-374 ◽  
Author(s):  
W N Smith ◽  
R L Desjardins ◽  
B. Grant ◽  
C. Li ◽  
R. Lemke ◽  
...  

Measured data from two experimental sites in Canada were used to test the ability of the DeNitrification and DeComposition model (DNDC) to predict N2O emissions from agricultural soils. The two sites, one from eastern Canada, and one from western Canada, provided a variety of crops, management practices, soils, and climates for testing the model. At the site in eastern Canada, the magnitude of total seasonal N2O flux from the seven treatments was accurately predicted with a slight average over-prediction (ARE) of 3% and a coefficient of variation of 41%. Nitrous oxide emissions based on International Panel for Climate Change (IPCC) methodology had a relative error of 62% for the seven treatments. The DNDC estimates of total yearly emissions of N2O from the field site in western Canada showed an underestimation of 8% for the footslope landscape position and an overestimation of 46% for the shoulder position. The data input for the DNDC model were not of sufficient detail to characterize the moisture difference between the landscape positions. The estimates from IPCC guidelines showed an underestimation of 54% for the footslope and an overestimation of 161% for the shoulder. The results indicate that the DNDC model was more accurate than IPCC methodology at estimating N2O emissions at both sites. Key words: Nitrous oxide, DNDC, soil model, greenhouse gas, testing


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