Feeding lucerne silage to beef cattle at three allowances and four feeding frequencies affects circadian patterns of methane emissions, but not emissions per unit of intake

2014 ◽  
Vol 54 (9) ◽  
pp. 1350 ◽  
Author(s):  
Arjan Jonker ◽  
German Molano ◽  
Christopher Antwi ◽  
Garry Waghorn
Keyword(s):  
Emission Rate ◽  
Circadian Variation ◽  
Emission Rates ◽  
Ch4 Emission ◽  
Feeding Frequency ◽  
Ch4 Emissions ◽  
Time To Peak ◽  
Ch4 Production ◽  
Ad Libitum ◽  
Circadian Patterns

The objective of this study was to determine the circadian variation in methane (CH4) emissions from cattle fed lucerne silage at different feeding levels and feeding frequencies, to assist with interpretation of short ‘snapshot’ CH4 measurements used for predicting daily emissions. Eight Hereford × Friesian heifers (initially 20 months of age) were used in five consecutive periods (P1–5) of 14 days with CH4 emissions measured using respiration chambers for two consecutive days at the end of each period. Feed was restricted to intakes of ~6, 8, 8, 8 and 11 ± 1.3 (ad libitum) kg lucerne silage dry matter (DM), fed in 2, 2, 3, 4 or ad libitum (refilled twice daily) meals per day in P1–5, respectively. Daily CH4 production (g/day) was lower in P1 than in P2–4 (P < 0.05), which were lower than in P5 (P < 0.05), but CH4 yield (24.3 ± 1.23 g/kg DM) was unaffected by treatment. Among the five periods, CH4 emission rate (g/h) before feeding ranged from 1.8 to 6.5 g/h, time to peak CH4 production after start of feeding ranged from 19 to 40 min and peak CH4 production rate ranged from 11.1 to 17.5 g/h. The range in hourly CH4 emission rates during the day decreased with increasing feed intake level, but was unaffected by feeding frequency. In summary, the circadian pattern of CH4 emissions was affected by feed allowance and feeding frequency, and variation in CH4 emission rate was reduced with increasing intake, without affecting average daily yield (g CH4/kg DM intake).

A comment on scaling methane emissions from vegetation and grazing ruminants in New Zealand

2006 ◽  
Vol 33 (7) ◽  
pp. 613 ◽  
Author(s):  
Francis M. Kelliher ◽  
Harry Clark ◽  
Zheng Li ◽  
Paul C. D. Newton ◽  
Anthony J. Parsons ◽  
...  
Keyword(s):  
New Zealand ◽  
Standard Deviation ◽  
Forest Canopy ◽  
Emission Rate ◽  
Oxidative Capacity ◽  
Emission Rates ◽  
Ch4 Emission ◽  
Ch4 Emissions ◽  
Grazed Pasture ◽  
Indigenous Forest

Keppler et al. (2006, Nature 439, 187–191) showed that plants produce methane (CH4) in aerobic environments, leading Lowe (2006, Nature 439, 148–149) to postulate that in countries such as New Zealand, where grazed pastures have replaced forests, the forests could have produced as much CH4 as the ruminants currently grazing these areas. Estimating CH4 emissions from up to 85 million ruminants in New Zealand is challenging and, for completeness, the capacity of forest and pastoral soils to oxidise CH4 should be included. On average, the CH4 emission rate of grazing ruminants is estimated to be 9.6 ± 2.6 g m–2 year–1 (±standard deviation), six times the corresponding estimate for an indigenous forest canopy (1.6 ± 1.1 g m–2 year–1). The forest’s soil is estimated to oxidise 0.9 ± 0.2 g m–2 year–1 more CH4 than representative soils beneath grazed pasture. Taking into account plant and animal sources and the soil’s oxidative capacity, the net CH4 emission rates of forest and grazed ecosystems are 0.6 ± 1.1 and 9.8 ± 2.6 g m–2 year–1, respectively.

scholarly journals Present state of global wetland extent and wetland methane modelling: conclusions from a model inter-comparison project (WETCHIMP)

2013 ◽  
Vol 10 (2) ◽  
pp. 753-788 ◽  
Author(s):  
J. R. Melton ◽  
R. Wania ◽  
E. L. Hodson ◽  
B. Poulter ◽  
B. Ringeval ◽  
...  
Keyword(s):  
Large Scale ◽  
Positive Response ◽  
Co2 Concentration ◽  
Remotely Sensed ◽  
Atmospheric Co2 ◽  
Emission Rates ◽  
Ch4 Emission ◽  
Wetland Area ◽  
Large Variability ◽  
Ch4 Emissions

Abstract. Global wetlands are believed to be climate sensitive, and are the largest natural emitters of methane (CH4). Increased wetland CH4 emissions could act as a positive feedback to future warming. The Wetland and Wetland CH4 Inter-comparison of Models Project (WETCHIMP) investigated our present ability to simulate large-scale wetland characteristics and corresponding CH4 emissions. To ensure inter-comparability, we used a common experimental protocol driving all models with the same climate and carbon dioxide (CO2) forcing datasets. The WETCHIMP experiments were conducted for model equilibrium states as well as transient simulations covering the last century. Sensitivity experiments investigated model response to changes in selected forcing inputs (precipitation, temperature, and atmospheric CO2 concentration). Ten models participated, covering the spectrum from simple to relatively complex, including models tailored either for regional or global simulations. The models also varied in methods to calculate wetland size and location, with some models simulating wetland area prognostically, while other models relied on remotely sensed inundation datasets, or an approach intermediate between the two. Four major conclusions emerged from the project. First, the suite of models demonstrate extensive disagreement in their simulations of wetland areal extent and CH4 emissions, in both space and time. Simple metrics of wetland area, such as the latitudinal gradient, show large variability, principally between models that use inundation dataset information and those that independently determine wetland area. Agreement between the models improves for zonally summed CH4 emissions, but large variation between the models remains. For annual global CH4 emissions, the models vary by ±40% of the all-model mean (190 Tg CH4 yr−1). Second, all models show a strong positive response to increased atmospheric CO2 concentrations (857 ppm) in both CH4 emissions and wetland area. In response to increasing global temperatures (+3.4 °C globally spatially uniform), on average, the models decreased wetland area and CH4 fluxes, primarily in the tropics, but the magnitude and sign of the response varied greatly. Models were least sensitive to increased global precipitation (+3.9 % globally spatially uniform) with a consistent small positive response in CH4 fluxes and wetland area. Results from the 20th century transient simulation show that interactions between climate forcings could have strong non-linear effects. Third, we presently do not have sufficient wetland methane observation datasets adequate to evaluate model fluxes at a spatial scale comparable to model grid cells (commonly 0.5°). This limitation severely restricts our ability to model global wetland CH4 emissions with confidence. Our simulated wetland extents are also difficult to evaluate due to extensive disagreements between wetland mapping and remotely sensed inundation datasets. Fourth, the large range in predicted CH4 emission rates leads to the conclusion that there is both substantial parameter and structural uncertainty in large-scale CH4 emission models, even after uncertainties in wetland areas are accounted for.

scholarly journals Hysteretic temperature sensitivity of wetland CH<sub>4</sub> fluxes explained by substrate availability and microbial activity

2020 ◽  
Author(s):  
Kuang-Yu Chang ◽  
William J. Riley ◽  
Patrick M. Crill ◽  
Robert F. Grant ◽  
Scott R. Saleska
Keyword(s):  
Temperature Sensitivity ◽  
Global Climate ◽  
Mechanistic Modeling ◽  
Biogeochemical Model ◽  
Ch4 Emission ◽  
Substrate Availability ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Biogeochemical Models ◽  
Abiotic Interactions

Abstract. Methane (CH4) emissions from wetlands are likely increasing and important in global climate change assessments. However, contemporary terrestrial biogeochemical model predictions of CH4 emissions are very uncertain, at least in part due to prescribed temperature sensitivity of CH4 production and emission. While statistically consistent apparent CH4 emission temperature dependencies have been inferred from meta-analyses across microbial to ecosystem scales, year-round ecosystem-scale observations have contradicted that finding. Using flux observations and mechanistic modeling in two heavily studied high-latitude research sites (Stordalen, Sweden, and Utqiaġvik, Alaska, USA), we show here that substrate-mediated hysteretic microbial and abiotic interactions lead to intra-seasonally varying temperature sensitivity of CH4 production and emission. We find that seasonally varying substrate availability drives lower and higher modeled methanogen biomass and activity, and thereby CH4 production, during the earlier and later periods of the thawed season, respectively. Our findings demonstrate the uncertainty of inferring CH4 emission or production from temperature alone, and highlight the need to represent microbial and abiotic interactions in wetland biogeochemical models.

scholarly journals Improved methane emission estimates using AVIRIS-NG and an Airborne Doppler Wind Lidar

2021 ◽  
Author(s):  
Andrew Thorpe ◽  
Christopher O’Handley ◽  
George Emmitt ◽  
Philip Decola ◽  
Francesca Hopkins ◽  
...  
Keyword(s):  
Wind Speed ◽  
Emission Rate ◽  
Sonic Anemometer ◽  
Surface Measurement ◽  
Emission Rates ◽  
Ch4 Emission ◽  
Near Surface ◽  
Wind Measurements ◽  
Wind Lidar ◽  
Doppler Wind Lidar

&lt;p&gt;This study demonstrates the utility of combining Airborne Doppler Wind Lidar measurements and quantitative methane (CH4) retrievals from the Next Generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) to estimate CH4 emission rates. In a controlled release experiment, Twin Otter Doppler Wind Lidar (TODWL) observed wind speed and direction agreed closely with sonic anemometer measurements and CH4 emission rates derived from TODWL observations were more accurate than those using the sonic during periods of stable winds. During periods exhibiting rapid shifts in wind speed and direction, estimating emission rates proved more challenging irrespective of the use of model, sonic, or TODWL wind data. Overall, TODWL was able to provide accurate wind measurements and emission rate estimates despite the variable wind conditions and excessive flight level turbulence which impacted near surface measurement density. TODWL observed winds were also used to constrain CH4 emissions at a refinery, landfill, wastewater facility, and dairy digester. At these sites, TODWL wind measurements agreed well with wind observations from nearby meteorological stations, and when combined with quantitative CH4 plume imagery, yielded emission rate estimates that were similar to those obtained using model winds.&lt;/p&gt;

scholarly journals Evaluating alternative ebullition models for predicting peatland methane emission and its pathways via data-model fusion

2021 ◽  
Author(s):  
Shuang Ma ◽  
Lifen Jiang ◽  
Rachel M. Wilson ◽  
Jeff P. Chanton ◽  
Scott Bridgham ◽  
...  
Keyword(s):  
Model Parameters ◽  
Ch4 Emission ◽  
Deep Soil ◽  
Concentration Data ◽  
Ch4 Flux ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Underlying Mechanisms ◽  
Improved Model ◽  
Threshold Approach

Abstract. Understanding the dynamics of peatland methane (CH4) emissions and quantifying sources of uncertainty in estimating peatland CH4 emissions are critical for mitigating climate change. The relative contributions of CH4 emission pathways through ebullition, plant-mediated transport, and diffusion together with their different transport rates and vulnerability to oxidation determine the quantity of CH4 to be oxidized before leaving the soil. Notwithstanding their importance, the relative contributions of the emission pathways have not been well characterized by experiments or modeling approaches. In particular, the ebullition process is more uncertain and can lead to large uncertainties in modeled CH4 emissions. To improve model simulations of CH4 emission and its pathways, we evaluated two model structures: 1) the Ebullition Bubble Growth volume threshold approach (EBG) and 2) the modified Ebullition Concentration Threshold approach (ECT) using CH4 flux and concentration data collected in a peatland in northern Minnesota, USA. When model parameters were constrained using observed CH4 fluxes, the CH4 emissions simulated by the EBG approach (RMSE = 0.53) had a better agreement with observations than the ECT approach (RMSE = 0.61). Further, the EBG approach simulated a smaller contribution from ebullition but more frequent ebullition events than the ECT approach. The EBG approach yielded greatly improved simulations of pore water CH4 concentrations, especially in the deep soil layers, compared to the ECT approach. When constraining the EBG model with both CH4 flux and concentration data in model-data fusion, uncertainty of the modeled CH4 concentration profiles was reduced by 78 to 86 % in comparison to constraints based on CH4 flux data alone. The improved model capability was attributed to the well-constrained parameters regulating the CH4 production and emission pathways. Our results suggest that the EBG modeling approach better characterizes CH4 emission and underlying mechanisms. Moreover, to achieve the best model results both CH4 flux and concentration data are required to constrain model parameterization.

scholarly journals Methane production and nitrogen balance of dairy heifers grazing palisade grass cv. Marandu alone or with forage peanut

2019 ◽  
Vol 97 (11) ◽  
pp. 4625-4634 ◽  
Author(s):  
Andressa S Berça ◽  
Abmael Da S Cardoso ◽  
Vanessa Z Longhini ◽  
Luís O Tedeschi ◽  
Robert Michael Boddey ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Management Strategies ◽  
N Fertilization ◽  
Neutral Detergent Fiber ◽  
N Balance ◽  
Ch4 Emission ◽  
Purine Derivatives ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Ch4 Production

Abstract Livestock production systems are an essential agribusiness activity in Brazil, but a critical challenge of Brazilian farmers is to maintain the equilibrium of the ecosystem, using herbage resources efficiently with a minimum impact on the environment. Nitrogen (N) fertilization and the inclusion of forage legumes into tropical grass pastures are management strategies which increase the productivity and nutritive value of pastures and may also affect methane (CH4) production by ruminants. The objective of this study was to examine the effects of either fertilizing palisade grass pastures with N or including the forage peanut (Arachis pintoi) into grass pastures on enteric CH4 emission, microbial protein production in the rumen via purine derivatives in the urine, and N balance. Twenty-one nonlactating crossbred dairy heifers were used in a completely randomized design with 3 treatments. The treatments consisted of pastures of palisade grass without N fertilization (control), fertilized with urea (fertilized), and palisade grass mixed with forage peanut (mixed). Seven animals (replications) were used to evaluate dry matter intake, digestibility, CH4 emission, urea, purine derivatives, and volume of urine, and N ingestion and excretion. Four paddocks (replications) were used to measure herbage mass; morphological, botanical, and chemical composition of herbage; and herbage allowance. The CH4 emissions were determined using the sulfur hexafluoride (SF6) tracer gas technique. The efficiency of N utilization (ENU) was calculated using the N balance data. Crude protein (CP) concentration of herbage increased with fertilization or legumes inclusion (P < 0.0001) while neutral detergent fiber (NDF) concentration decreased (P = 0.0355). The leaf allowance was higher in the fertilized treatment (P = 0.0294). Only uric acid excretion increased with N fertilization (P = 0.0204). The ENU was not affected by fertilized or mixed compared to control and averaged 55% (P = 0.8945). The enteric CH4 production was similar between treatments and averaged 129 g/d (P = 0.3989). We concluded that the changes in chemical composition of herbage provided by N fertilization or the inclusion of the legume showed no reduction in enteric CH4 emissions, but the ENU was more significant than previous studies with palisade grass, suggesting that different management strategies might alter the ENU under grazing conditions.

scholarly journals A comment on the quantitative significance of aerobic methane release by plants

2006 ◽  
Vol 33 (6) ◽  
pp. 521 ◽  
Author(s):  
Miko U. F. Kirschbaum ◽  
Dan Bruhn ◽  
David M. Etheridge ◽  
John R. Evans ◽  
Graham D. Farquhar ◽  
...  
Keyword(s):  
Physiological State ◽  
Underlying Mechanism ◽  
Global Scale ◽  
Emission Rates ◽  
Ch4 Emission ◽  
Limited Information ◽  
Mitigation Option ◽  
Sources And Sinks ◽  
Ch4 Emissions ◽  
Dead Plant

A recent study by Keppler et al. (2006; Nature 439, 187–191) demonstrated CH4 emission from living and dead plant tissues under aerobic conditions. This work included some calculations to extrapolate the findings from the laboratory to the global scale and led various commentators to question the value of planting trees as a greenhouse mitigation option. The experimental work of Keppler et al. (2006) appears to be largely sound, although some concerns remain about the quantification of emission rates. However, whilst accepting their basic findings, we are critical of the method used for extrapolating results to a global scale. Using the same basic information, we present alternative calculations to estimate global aerobic plant CH4 emissions as 10–60 Mt CH4 year–1. This estimate is much smaller than the 62–236 Mt CH4 year–1 reported in the original study and can be more readily reconciled within the uncertainties in the established sources and sinks in the global CH4 budget. We also assessed their findings in terms of their possible relevance for planting trees as a greenhouse mitigation option. We conclude that consideration of aerobic CH4 emissions from plants would reduce the benefit of planting trees by between 0 and 4.4%. Hence, any offset from CH4 emission is small in comparison to the significant benefit from carbon sequestration. However, much critical information is still lacking about aerobic CH4 emission from plants. For example, we do not yet know the underlying mechanism for aerobic CH4 emission, how CH4 emissions change with light, temperature and the physiological state of leaves, whether emissions change over time under constant conditions, whether they are related to photosynthesis and how they relate to the chemical composition of biomass. Therefore, the present calculations must be seen as a preliminary attempt to assess the global significance from a basis of limited information and are likely to be revised as further information becomes available.

scholarly journals Factors influencing CO<sub>2</sub> and CH<sub>4</sub> emissions from coastal wetlands in the Liaohe Delta, Northeast China

2015 ◽  
Vol 12 (4) ◽  
pp. 3469-3503 ◽  
Author(s):  
L. Olsson ◽  
S. Ye ◽  
X. Yu ◽  
M. Wei ◽  
K. W. Krauss ◽  
...  
Keyword(s):  
Water Table ◽  
Coastal Wetlands ◽  
Northeast China ◽  
Ecosystem Respiration ◽  
Soil Surface ◽  
Emission Rates ◽  
Ch4 Emission ◽  
Ch4 Emissions ◽  
Water Tables ◽  
Liaohe Delta

Abstract. Many factors are known to influence greenhouse gas emissions from coastal wetlands, but it is still unclear which factors are most important under field conditions when they are all acting simultaneously. The objective of this study was to assess the effects of water table, salinity, soil temperature and vegetation on CH4 emissions and ecosystem respiration (Reco) from five coastal wetlands in the Liaohe Delta, northeast China: two Phragmites australis (common reed) wetlands, two Suaeda salsa (sea blite) marshes and a rice (Oryza sativa) paddy. Throughout the growing season, the Suaeda wetlands were net CH4 sinks whereas the Phragmites wetlands and the rice paddy were net CH4 sources emitting 1.2–6.1 g CH4 m−2 y−1. The Phragmites wetlands emitted the most CH4 per unit area and the most CH4 relative to CO2. The main controlling factors for the CH4 emissions were water table, temperature and salinity. The CH4 emission was accelerated at high and constant (or managed) water tables and decreased at water tables below the soil surface. High temperatures enhanced CH4 emissions, and emission rates were consistently low (< 1 mg CH4 m−2 h) at soil temperatures <18 °C. At salinity levels > 18 ppt, the CH4 emission rates were always low (< 1 mg CH4 m−2 h−1) probably because methanogens were outcompeted by sulphate reducing bacteria. Saline Phragmites wetlands can, however, emit significant amounts of CH4 as CH4 produced in deep soil layers are transported through the air-space tissue of the plants to the atmosphere. The CH4 emission from coastal wetlands can be reduced by creating fluctuating water tables, including water tables below the soil surface, as well as by occasional flooding by high-salinity water. The effects of water management schemes on the biological communities in the wetlands must, however, be carefully studied prior to the management in order to avoid undesirable effects on the wetland communities.

scholarly journals Hysteretic temperature sensitivity of wetland CH<sub>4</sub> fluxes explained by substrate availability and microbial activity

2020 ◽  
Vol 17 (22) ◽  
pp. 5849-5860
Author(s):  
Kuang-Yu Chang ◽  
William J. Riley ◽  
Patrick M. Crill ◽  
Robert F. Grant ◽  
Scott R. Saleska
Keyword(s):  
Temperature Sensitivity ◽  
Seasonal Variability ◽  
Global Climate ◽  
Biogeochemical Model ◽  
Ch4 Emission ◽  
Substrate Availability ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Biogeochemical Models ◽  
Abiotic Interactions

Abstract. Methane (CH4) emissions from wetlands are likely increasing and important in global climate change assessments. However, contemporary terrestrial biogeochemical model predictions of CH4 emissions are very uncertain, at least in part due to prescribed temperature sensitivity of CH4 production and emission. While statistically consistent apparent CH4 emission temperature dependencies have been inferred from meta-analyses across microbial to ecosystem scales, year-round ecosystem-scale observations have contradicted that finding. Here, we show that apparent CH4 emission temperature dependencies inferred from year-round chamber measurements exhibit substantial intra-seasonal variability, suggesting that using static temperature relations to predict CH4 emissions is mechanistically flawed. Our model results indicate that such intra-seasonal variability is driven by substrate-mediated microbial and abiotic interactions: seasonal cycles in substrate availability favors CH4 production later in the season, leading to hysteretic temperature sensitivity of CH4 production and emission. Our findings demonstrate the uncertainty of inferring CH4 emission or production rates from temperature alone and highlight the need to represent microbial and abiotic interactions in wetland biogeochemical models.

scholarly journals Pendugaan Emisi Metana pada Sistem Pengelolaan Tanaman Padi di Kabupaten Minahasa (The Estimation of Methane Emission in The Rice Management System in Minahasa Rregency)

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Susan Marlein Mambu
Keyword(s):  
Methane Emission ◽  
Rice Fields ◽  
Soil Types ◽  
Wetland Rice ◽  
Calculation Formula ◽  
Ch4 Emission ◽  
Irrigated Rice ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Over Time

AbstrakPemanasan bumi secara global karena emisi gas rumah kaca ke atmosfir yang disebabkan oleh kegiatan manusia, cenderung mengalami peningkatan dari waktu ke waktu. Pertanian padi sawah, khususnya sawah teririgasi juga merupakan penyumbang terbesar gas metana ke atmosfer. Oleh karena itu, perlu adanya upaya pengurangan emisi CH4 dari kegiatan budidaya tanaman padi sawah. Penelitian dilakukan untuk mengetahui emisi CH4 dari budidaya padi sawah di kabupaten Minahasa, dengan melakukan estimasi emisi CH4 menggunakan model perhitungan formula untuk estimasi emisi CH4 pada padi sawah. Hasil penelitian ini memberikan informasi keberadaan CH4 dan jumlah produksi emisi CH4 dari lahan padi sawah di Kabupaten Minahasa, yang cenderung mengalami peningkatan dari tahun ke tahun (data tahun 2002 – 2010). Peningkatan emisi CH4 dari lahan padi sawah di Kabupaten Minahasa disebabkan oleh beberapa faktor yaitu luas panen, jenis tanah, jenis varietas, jenis pengairan dan kegiatan budidaya lainnya seperti pemupukan dan pemberian bahan organik (jerami).Kata kunci: emisi metana, padi sawahAbstractGlobal warming from greenhouse gas emissions to the atmosphere that is caused by human activities tends to be increased over time. Fields of wetland rice, particularly irrigated rice, are also the largest contributor to methane gas to the atmosphere. Therefore, CH4 emissions should be reduced from paddy rice cultivation. This research aimed to measure the production of CH4 emission in the wetland rice fields of Minahasa, using a model calculation formula to estimate CH4 emissions in the rice fields. The results informed the existence and the amount of CH4 production resulted from wetland rice fields in Minahasa, which tended to be increased from year to year (data of year 2002 to 2010). The increment of CH4 emission from wetland rice fields in Minahasa was caused by several factors, i.e. the harvested area, soil types, types of variety, types of irrigation and other cultivation activities such as fertilization and providing organic material (straw).Keywords: methane emission, wetland rice

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