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Methane is the simplest hydrocarbon, consisting of one carbon atom and four hydrogen atoms. It is abundant in marsh gas, livestock rumination, and combustible ice. Little is known about the use of methane in human disease treatment. Current research indicates that methane is useful for treating several diseases including ischemia and reperfusion injury, and inflammatory diseases. The mechanisms underlying the protective effects of methane appear primarily to involve anti-oxidation, anti-inflammation, and anti-apoptosis. In this review, we describe the beneficial effects of methane on different diseases, summarize possible mechanisms by which methane may act in these conditions, and discuss the purpose of methane production in hypoxic conditions. Then we propose several promising directions for the future research.

Marsh gas is an important type of renewable energies and plays important role to solve the energy issue in remote countryside. This article captures the development of marsh gas in Gongcheng County of China with game theory model. Firstly, the development history of marsh gas in Gongcheng County is introduced. Secondly, the economic effects of all subsidy strategy are discussed. Subsidy to family marsh gas popularizes the marsh gas. Thirdly, whether to subsidize firms depends on transportation costs. Therefore, for the disperse residents, subsidy to family marsh gas seems more rational than that to firms. For concentrated residents, the conclusions are contrary. Keywords: Subsidy, Energy, Bioenergy, Forest, Gongcheng, Countryside development

Direct-fed microbials (DFM) are considered as a promising technique to improve animal productivity without affecting animal health or harming the environment. The potential of three bacterial DFM to reduce methane (CH4) emissions, modulate ruminal fermentation, milk production and composition of primiparous dairy cows was examined in this study. As previous reports have shown that DFM respond differently to different diets, two contrasting diets were used in this study. Eight lactating primiparous cows were randomly divided into two groups that were fed a corn silage-based, high-starch diet (HSD) or a grass silage-based, high-fiber diet (HFD). Cows in each dietary group were randomly assigned to four treatments in a 4 × 4 Latin square design. The bacterial DFM used were selected for their proven CH4-reducing effect in vitro. Treatments included control (without DFM) and 3 DFM treatments: Propionibacterium freudenreichii 53-W (2.9 × 1010 colony forming units (CFU)/cow per day), Lactobacillus pentosus D31 (3.6 × 1011 CFU/cow per day) and Lactobacillus bulgaricus D1 (4.6 × 1010 CFU/cow per day). Each experimental period included 4 weeks of treatment and 1 week of wash-out, with measures performed in the fourth week of the treatment period. Enteric CH4 emissions were measured during 3 consecutive days using respiration chambers. Rumen samples were collected for ruminal fermentation parameters and quantitative microbial analyses. Milk samples were collected for composition analysis. Body weight of cows were recorded at the end of each treatment period. Irrespective of diet, no mitigating effect of DFM was observed on CH4 emissions in dairy cows. In contrast, Propionibacterium increased CH4 intensity by 27% (g CH4/kg milk) in cows fed HSD. There was no effect of DFM on other fermentation parameters and on bacterial, archaeal and protozoal numbers. Similarly, the effect of DFM on milk fatty acid composition was negligible. Propionibacterium and L. pentosus DFM tended to increase body weight gain with HSD. We conclude that, contrary to the effect previously observed in vitro, bacterial DFM Propionibacterium freudenreichii 53-W, Lactobacillus pentosus D31 and Lactobacillus bulgaricus D1 did not alter ruminal fermentation and failed to reduce CH4 emissions in lactating primiparous cows fed high-starch or high-fiber diets. Electronic supplementary material The online version of this article (10.1186/s40104-019-0342-9) contains supplementary material, which is available to authorized users.

Waste produced in a country is broadly categorized in two types, firstly organic waste and the other inorganic waste. Organic waste is harmful to human race, as when left untreated releases harmful gases like carbon dioxide, methane, hydrogen sulphide, combination of these gases is called march gas. Marsh gas penetrates underground with rainwater polluting underground water belt thus treatment of organic waste is very essential. The common techniques used in organic waste management are dumping waste in landfills, burning waste. At industrial level waste is treated through incineration, fast fermentation, composting, biogas chambers and black soldier flies (BSF). Organic waste management with the help of black soldier flies, is a technique which does not produce any toxic end product like all the other techniques which can harm the environment. BSF technique is not very popular as a lot of human involvement is required in the process thus to overcome this an electrically controlled artificial system for organic waste management using black soldier flies with IOT monitoring is designed. The system involves minimum human interaction by artificially providing environment conditions for survival of black soldier flies larvae which are responsible for organic waste treatment. The whole system can be monitored using IOT from anywhere in the world. The monitoring of the system is done with the help of sensors. The end product of the system is not toxic for environment rather it can produce income by selling the end product as a food for other animals and fertilizer for crops.

International audience; A possible driver of feed inefficiency in dairy cows is overconsumption. The objective was therefore to test precision feed restriction as a lever to improve feed efficiency of the least efficient lactating dairy cows. An initial cohort of 68 Holstein lactating cows was monitored from calving to end of ad libitum feeding at 196 ± 16 d in milk, with the last 70 d being used to estimate feed efficiency. For a given expected dry matter (DM) intake (DMI) during ad libitum feeding, offered DMI during restriction was set to observed DMI of the 10% most efficient cows during ad libitum feeding for similar performance. Feed restriction lasted during 92 d, with only the last 70 d being used for data analyses. A single diet was fed during ad libitum and restriction periods, and was based on 64.9% of corn silage and 35.1% of concentrates on a DM basis. Individual DMI, body weight, milk production, milk composition, and body condition score were recorded, as well as methane emissions. Feed efficiency was defined as the repeatable part of the random effect of cow on the intercept in a mixed model predicting DMI with net energy in milk, maintenance and body weight gain and loss within parity, feeding level, and time. Milk energy efficiency was estimated in the same way, predicting net energy in milk instead of DMI. The 15 least efficient cows ate 2.6 kg of DM/d more than the 15 most efficient cows during ad libitum feeding with 2 g/kg of DMI lower methane yield, but similar daily methane emissions. Feed restriction decreased DMI by 2.6 kg of DMI/d for the least efficient cows, which was 1.8 kg of DMI/d more than the most efficient cows, and decreased daily methane emissions by 49.2 g/d for the least efficient cows, which was 22.4 g/d more than the most efficient cows. Feed restriction had no significant effect on milk, body weight, or body weight change. Feed restriction reduced the variability of both milk energy and feed efficiencies, as shown by a decrease of their standard deviation from 0.87 to 0.69 kg of DM/d for feed efficiency and from 1.14 to 0.65 UFL/d for milk energy efficiency. Despite narrow efficiency differences, the most efficient cows during ad libitum feeding remained more efficient during feed restriction (r = 0.46 for feed efficiency and 0.49 for milk energy efficiency). The 2 efficiency groups no longer differed in feed efficiency during precision feed restriction. Precision feed restriction seemed to bring the least efficient cows closer to the most efficient cows and to reduce their methane emissions without impairing their performance.

With the popularization of municipal sewage treatment facilities, the improvement of sewage treatment efficiency and the deepening degree of sewage treatment, the sludge production of sewage plant has been sharply increased. Carbon emission during the process of municipal sewage treatment and disposal has become one of the important sources of greenhouse gases that cause greenhouse effect. How to reduce carbon dioxide emissions during sewage treatment and disposal process is of great significance for reducing air pollution. Kitchen waste and excess sludge, as two important organic wastes, once uses anaerobic synergetic digestion technology in the treatment process can on the one hand, avoid instability of sludge individual anaerobic digestion, improve sludge degradation rate and marsh gas production rate, and on the other hand, help increase the reduction of carbon dioxide emissions to a great extent. The paper uses material balance method, analyzes and calculates the carbon dioxide emissions from kitchen waste and sludge disposed by the anaerobic synergetic digestion technology, compares the anaerobic synergetic digestion technology with traditional sludge sanitary landfill technology and works out the carbon dioxide emission reductions after synergetic digestion. It takes the kitchen waste and sludge synergetic digestion engineering project of Zhenjiang city in Jiangsu province as an example, makes material balance analysis using concrete data and works out the carbon dioxide daily emission reductions. The paper analyzes the actual situation of emission reduction by comparing the data, and found that the synergetic digestion of kitchen waste and sludge can effectively reduce the carbon dioxide emission, and the reduction is obvious especially compared with that of sludge sanitary landfill, which has a certain effect on whether to promote the use of the technology.

This study investigated the effects of bacterial direct fed microbials (DFM) on ruminal fermentation and microbial characteristics, methane (CH4) emission, diet digestibility, and milk fatty acid (FA) composition in dairy cows fed diets formulated to induce different ruminal volatile fatty acid (VFA) profiles. Eight ruminally cannulated dairy cows were divided into 2 groups based on parity, days in milk, milk production, and body weight. Cows in each group were fed either a high-starch (38%, HS) or a low-starch (2%, LS) diet in a 55:45 forage-to-concentrate ratio on a dry matter (DM) basis. For each diet, cows were randomly assigned to 1 of 4 treatments in a Latin square design of (1) control (CON); (2) Propionibacterium P63 (P63); (3) P63 plus Lactobacillus plantarum 115 (P63+Lp); (4) P63 plus Lactobacillus rhamnosus 32(P63+Lr). Strains of DFM were administered at 10(10) cfu/d. Methane emission (using the sulfur hexafluoride tracer technique), total-tract digestibility, dry matter intake, and milk production and composition were quantified in wk 3. Ruminal fermentation and microbial characteristics were measured in wk 4. Data were analyzed using the mixed procedure of SAS (SAS Institute Inc., Cary, NC). The 2 diets induced different ruminal VFA profiles, with a greater proportion of propionate at the expense of acetate and butyrate for the HS diet. Greater concentrations of total bacteria and selected bacterial species of methanogenic Archaea were reported for the HS diet, whereas the protozoa concentration in HS decreased. For both diets, bacterial DFM supplementation raised ruminal pH (+0.18 pH units, on average) compared with CON. Irrespective of diet, P63+Lp and P63+Lr increased ruminal cellulase activity (3.8-fold, on average) compared with CON, but this effect was not associated with variations in ruminal microbial numbers. Irrespective of diet, no effect of bacterial DFM on ruminal VFA was observed. For the LS diet, supplementing cows with P63+Lr tended to decrease CH4 emission (26.5%, on average, when expressed per kilogram of milk or 4% fat-corrected milk). Only P63 supplementation to cows fed the HS diet affected the concentration of some milk FA, such as cis isomers of 18:1 and intermediates of ruminal biohydrogenation of polyunsaturated FA. Overall, bacterial DFM could be useful to stabilize ruminal pH. Their effects on CH4 production mitigation and milk FA profile depended on DFM strain and diet and should be confirmed under a greater variation of dietary conditions.

The antimethanogenic compound 3-nitrooxypropanol (3NOP) has been proven efficient to reduce methane (CH4) emissions from ruminants but it has been tested mainly on high-producing dairy cows fed high-concentrate diets. The aim of this work was to test the effect of 3NOP on CH4 emissions from medium-yielding cows fed a high-forage diet. Twenty-eight lactating dairy cows were recruited within 7-11 days after calving and distributed in 2 balanced groups in a randomized block design. The treated group received 3NOP (60 mg/kg DM basis) in a total mixed ration during 105 days and the control group received a placebo. The diet had 75% forage (52% corn silage, 17% hay, 6% straw) plus 25% concentrate and was distributed once a day after the morning milking. Individual daily kinetics of CH4 emissions were quantified using the GreenFeed system (C-Lock Inc., Rapid City, SD, USA). Intake and milk production were recorded daily, and milk composition (fat, protein, lactose, urea) twice a week. Intake was reduced with 3NOP (-1.6 kg DM on average; P = 0.01) whereas milk production was similar between groups (34.7 kg/d of energy corrected milk on average; P = 0.28). Milk composition did not vary between groups. Feed conversion efficiency in animals tended to increase with 3NOP (1.37 vs. 1.46 kg milk/kg DM intake on average; P = 0.07). Methane emissions, CH4 yield and CH4 intensity were lower in the treated group throughout the 105 days (on average -31% g/d, -25% g/kg DM intake, and -30% g/kg energy corrected milk, P < 0.0001). When monitoring daily kinetics of CH4 emissions, we observed that the major mitigation effect of the 3NOP occurred after feeding by preventing the post-prandial peak of CH4 emissions (P < 0.001). In conclusion, the CH4-reduction effect persisted for the duration of the study in early lactation dairy cows fed a 75% forage-based diet. The additive consistently prevented the CH4 production peak after the main meal of the day (P < 0.001). In systems without a total mixed ration, 3NOP should still have a significant antimethanogenic effect if provided throughout the main daily feeding period.

The objective of this study was to evaluate the performance of existing models predicting enteric methane (CH) emissions, using a large database (3183 individual data from 103 in vivo studies on dairy and beef cattle, sheep and goats fed diets from different countries). The impacts of dietary strategies to reduce CH emissions, and of diet quality (described by organic matter digestibility (dOM) and neutral-detergent fiber digestibility (dNDF)) on model performance were assessed by animal category. The models were first assessed based on the root mean square prediction error (RMSPE) to standard deviation of observed values ratio (RSR) to account for differences in data between models and then on the RMSPE. For dairy cattle, the CH (g/d) predicting model based on feeding level (dry matter intake (DMI)/body weight (BW)), energy digestibility (dGE) and ether extract (EE) had the smallest RSR (0.66) for all diets, as well as for the high-EE diets (RSR = 0.73). For mitigation strategies based on lowering NDF or improving dOM, the same model (RSR = 0.48 to 0.60) and the model using DMI and neutral- and acid-detergent fiber intakes (RSR = 0.53) had the smallest RSR, respectively. For diets with high starch (STA), the model based on nitrogen, ADF and STA intake presented the smallest RSR (0.84). For beef cattle, all evaluated models performed moderately compared with the models of dairy cattle. The smallest RSR (0.83) was obtained using variables of energy intake, BW, forage content and dietary fat, and also for the high-EE and the low-NDF diets (RSR = 0.84 to 0.86). The IPCC Tier 2 models performed better when dietary STA, dOM or dNDF were high. For sheep and goats, the smallest RSR was observed from a model for sheep based on dGE intake (RSR = 0.61). Both IPCC models had low predictive ability when dietary EE, NDF, dOM and dNDF varied (RSR = 0.57 to 1.31 in dairy, and 0.65 to 1.24 in beef cattle). The performance of models depends mostly on explanatory variables and not on the type of data (individual vs. treatment means) used in their development or evaluation. Some empirical models give satisfactory prediction error compared with the error associated with measurement methods. For better prediction, models should include feed intake, digestibility and additional information on dietary concentrations of EE and structural and nonstructural carbohydrates to account for different dietary mitigating strategies., This study is part of the Joint Programming Initiative on Agriculture, Food Security and Climate Change (FACCE-JPI)’s “GLOBAL NETWORK” project and the “Feeding and Nutrition Network” (http://animalscience.psu.edu/fnn) of the Livestock Research Group within the Global Research Alliance for Agricultural Greenhouse Gases (www.globalresearchalliance.org). Authors gratefully acknowledge funding for this project from: USDA National Institute of Food and Agriculture (Grant no. 2014-67003-21979) University of California, Davis Sesnon Endowed Chair Program, USDA, and Austin Eugene Lyons Fellowship (University of California, Davis); Funding from USDA National Institute of Food and Agriculture Federal Appropriations under Project PEN 04539 and Accession number 1000803, DSM Nutritional Products (Basel, Switzerland), Pennsylvania Soybean Board (Harrisburg, PA, USA), Northeast Sustainable Agriculture Research and Education (Burlington, VT, USA), and PMI Nutritional Additives (Shoreview, MN, USA); the Ministry of Economic Affairs (the Netherlands; project BO-20-007-006; Global Research Alliance on Agricultural Greenhouse Gases), the Product Board Animal Feed (Zoetermeer, the Netherlands) and the Dutch Dairy Board (Zoetermeer, the Netherlands); The Cofund for Monitoring & Mitigation of Greenhouse Gases from Agri- and Silvi-culture (FACCE ERA-GAS)’s project Capturing Effects of Diet on Emissions from Ruminant Systems and the Dutch Ministry of Agriculture, Nature and Food Quality (AF-EU-18010 & BO-4400159-01); USDA National Institute of Food and Agriculture (Hatch Multistate NC-1042 Project Number NH00616-R; Project Accession Number 1001855) and the New Hampshire Agricultural Experiment Station (Durham, NH); French National Research Agency through the FACCE-JPI program (ANR-13-JFAC-0003-01); the Department of Agriculture, Food and the Marine, Ireland Agricultural GHG Research Initiative for Ireland (AGRI-I) project; Academy of Finland (No. 281337), Helsinki, Finland; Swiss Federal Office of Agriculture, Berne, Switzerland; the Department for Environment, Food and Rural Affairs (Defra; UK); Defra, the Scottish Government, DARD, and the Welsh Government as part of the UK’s Agricultural GHG Research Platform projects (www.ghgplatform.org.uk); INIA (Spain, project MIT01-GLOBALNET-EEZ); German Federal Ministry of Food and Agriculture (BMBL) through the Federal Office for Agriculture and Food (BLE); Swedish Infrastructure for Ecosystem Science (SITES) at Röbäcksdalen Research Station; Comisión Nacional de Investigación Científica y Tecnológica, Fondo Nacional de Desarrollo Científico y Tecnológico (Grant Nos. 11110410 and 1151355) and Fondo Regional de Tecnología Agropecuaria (FTG/RF-1028-RG); European Commission through SMEthane (FP7-SME-262270).

By incorporating the dynamical aspects of the respiration chamber data, the model allows further information on an individual animal’s rumen microbiome to be extracted. This represents a potential stepping stone to relating rumen microbial genes to parameters controlling the dynamics of rumen fermentation and hence methane production.

With the rapid development of science and technology and the global warming caused by climate change, the extreme climate and the global plate have frequent effects, which not only seriously influence on the ecological environment, but also the shortage of natural energy caused by over-exploitation of human beings. Various countries have recognized nowadays the importance of energy and carbon dioxide emissions reduction, and with the development of circular economy issues, the governments realize that waste water discharged from high-value animal husbandry is a reusable resource. The environmental protection agencies cooperate with other agricultural institutions together in order to promote the policy of “returning fertilizer to the field”. However, urine water will produce biogas during the treatment process. Its main component, methane (CH4), is 25 times more than carbon dioxide (CO2), and the greenhouse effect caused by methane is carbon dioxide. But if the relevant technology is purified, methane becomes a good source of heat energy. If it is introduced into the generating set, it can become the daily electricity demand. For example, the principle of biogas power generation is to use the pig’s excrement anaerobic and fermentation, then the gas generated in it is introduced into the generator to diversify energy utilization and make the effect of room gas reduction.In Taiwan, there is a unique geographical environment. The temperature is moderate and humid all year round which belongs to the maritime climate and makes all kinds of poultry grow well. The domestic stock farming output value accounts for about 30% of the total agricultural output value, and the pig industry value accounts for about 15% of the total agriculture, showing the importance of the pig industry in Taiwan. The government is responsible for taking care of the livelihood of the majority of pig farmers, taking into account environmental protection responsibilities, promoting agricultural and enterprise management, and raising green energy pigs. Marsh gas power generation is relatively stable compared to wind and solar power. It does not have to depend on the weather and it can also supply electricity during peak hours. For example, Denmark began the research 40 years ago. Marsh gas is not only the excrement of pigs, but also Cattle and sheep chicken manure, kitchen waste, animal carcasses, etc. In the process of bacteria decomposition of organic matter, it will release the main substances of biogas containing methane, carbon dioxide, hydrogen sulfide and other gases. In the light of this, the Industrial Technology Research Institute Branch in Taiwan has established the Office for Biogas Promotion Program in 2016. They actively promoted biogas promotion services, and gave relevant technology and knowledge to explore new energy opportunities and activate related industries.The international survey report pointed out that between 2050 and 2070, the main energy sources for human beings will gradually dry up. Therefore, the application of recycling economy and resource reuse are much more important. This researchers invited “ Universe Circular Technology” as the subject and we will discuss how enterprises respond to the government’s promotion of circular economy policies, realize the new agricultural development that the government vigorously promotes, and use the regeneration of resources to solve the problem of energy shortage in Taiwan.

This study concerns variability in agrosystem inputs that affect greenhouse gas emissions at the farm scale, when management practices differ from average practices. Many studies of agrosystems assume average management practices. However, existence of a wide variety of farm-management practices may result in extreme variations in estimated environmental impacts. This large variation raises the need to use statistical tools to model extreme situations and their consequences on agrosystems. For instance, methane emissions generated by enteric fermentation in dairy cattle are particularly studied because they are important at a global scale. We investigated how extreme variations in feeding practices in dairy production affect predicted methane emissions, using a methane-emission model based on existing equations that is easy to apply at the farm scale. In this study, extreme variations in the time that cattle spent grazing were propagated through three different dairy-production systems. For an intensive dairy farm, predicted methane emissions decreased up to 15% (ca. 5% on average) and increased up to 11% (ca. 1% on average) under extremely long or short times spent grazing, respectively, compared to those from average variations in the time spent grazing. The range of variation in time spent grazing also reflects changes in feed rations. Farm-management practices require deep investigation to both evaluate and decrease risks of environmental impacts in dairy production.

International audience; Methanogenic archaea occupy a functionally important niche in the gut microbial ecosystem of mammals. Our purpose was to quantitatively characterize the dynamics of methanogenesis by integrating microbiology, thermodynamics and mathematical modelling. For that, in vitro growth experiments were performed with pure cultures of key methanogens from the human and ruminant gut, namely Methanobrevibacter smithii, Methanobrevibacter ruminantium and Methanobacterium formicium. Microcalorimetric experiments were performed to quantify the methanogenesis heat flux. We constructed an energetic-based mathematical model of methanogenesis. Our model captured efficiently the dynamics of methanogenesis with average concordance correlation coefficients of 0.95 for CO2, 0.98 for H2 and 0.97 for CH4. Together, experimental data and model enabled us to quantify metabolism kinetics and energetic patterns that were specific and distinct for each species despite their use of analogous methane-producing pathways. Then, we tested in silico the interactions between these methanogens under an in vivo simulation scenario using a theoretical modelling exercise. In silico simulations suggest that the classical competitive exclusion principle is inapplicable to gut ecosystems and that kinetic information alone cannot explain gut ecological aspects such as microbial coexistence. We suggest that ecological models of gut ecosystems require the integration of microbial kinetics with nonlinear behaviours related to spatial and temporal variations taking place in mammalian guts. Our work provides novel information on the thermodynamics and dynamics of methanogens. This understanding will be useful to construct new gut models with enhanced prediction capabilities and could have practical applications for promoting gut health in mammals and mitigating ruminant methane emissions.

Une production de méthane à partir de dioxyde de carbone et d’électricité renouvelable

Avec le méthane entérique, l’élevage des ruminants contribue aux émissions de gaz à effet de serre (GES). En France, il représente 7 à 8 % des émissions totales de GES. L’intégration des émissions de CH4 à l’échelle du système d’élevage est peu décrite et l’analyse des possibles facteurs d’influence ouvre d’autres perspectives d’atténuation que celles connues à l’échelle individuelle. Les résultats issus de l’expérience à long terme « Quelle vache pour quel système ? » ont été valorisés afin de quantifier par modélisation les émissions de CH4 du troupeau laitier. L’influence de la race, de l’âge au 1er vêlage et de la stratégie d’alimentation a été étudiée. Pour un même volume de lait livré (400 t), les émissions totales annuelles de CH4 entérique varient de 10,7 à 19,2 t selon la race et la démographie des différents troupeaux. Ces quantités émises sont sensibles aux performances individuelles, au potentiel des vaches et aux stratégies d’alimentation favorables à son expression.L’aptitude à revêler et l’âge au 1er vêlage ont une influence importante sur les effectifs des différents troupeaux, donc sur les émissions. Intra système, différents leviers d’amélioration technique existent et sont souvent favorables à l’efficacité globale du système. L’impact de ces leviers doit être évalué globalement afin d’éviter de possibles effets défavorables associés sur l’environnement., With enteric methane, the ruminants contributes to greenhouse gases (GHG) emissions. In France, this represents 7 to 8% of the total GHG emissions. The integration of CH4 emissions at the livestock farming system level is poorly described and the influential factors analysis offers other possibilities for mitigation than at the animal level. The results of the long term experiment “The cow for the system?” have been combined to quantify by modeling the dairy herd CH4 emissions. The effect of the breed, the first calving age and the feeding strategy has been described. At the same level of milk sales (400 t), the enteric CH4 annual emissions vary from 10.7 to 19.2 t according to the breed and herds demography observed. The total CH4 released is sensitive to the individual performance and reduced with high genetic merit cows and high feeding strategies. The ability to be incalf and the first calving age have an influence on the herd size, and consequently, on the CH4 emissions. Within every system, different levers of technical improvement exist and are often associated with increased system efficiency. The impact of these levers has to be evaluated globally to avoid possible adverse associated effects on environment

Simulation models quantify the impacts on carbon (C) and nitrogen (N) cycling in grassland systems caused by changes in management practices. To support agricultural policies, it is however important to contrast the responses of alternative models, which can differ greatly in their treatment of key processes and in their response to management. We applied eight biogeochemical models at five grassland sites (in France, New Zealand, Switzerland, United Kingdom and United States) to compare the sensitivity of modelled C and N fluxes to changes in the density of grazing animals (from 100% to 50% of the original livestock densities), also in combination with decreasing N fertilization levels (reduced to zero from the initial levels). Simulated multi-model median values indicated that input reduction would lead to an increase in the C sink strength (negative net ecosystem C exchange) in intensive grazing systems: −64 ± 74 g C m−2 yr−1 (animal density reduction) and −81 ± 74 g C m−2 yr−1 (N and animal density reduction), against the baseline of −30.5 ± 69.5 g C m−2 yr−1 (LSU [livestock units] ≥ 0.76 ha−1 yr−1). Simulations also indicated a strong effect of N fertilizer reduction on N fluxes, e.g. N2O-N emissions decreased from 0.34 ± 0.22 (baseline) to 0.1 ± 0.05 g N m−2 yr−1 (no N fertilization). Simulated decline in grazing intensity had only limited impact on the N balance. The simulated pattern of enteric methane emissions was dominated by high model-to-model variability. The reduction in simulated offtake (animal intake + cut biomass) led to a doubling in net primary production per animal (increased by 11.6 ± 8.1 t C LSU−1 yr−1 across sites). The highest N2O-N intensities (N2O-N/offtake) were simulated at mown and extensively grazed arid sites. We show the possibility of using grassland models to determine sound mitigation practices while quantifying the uncertainties associated with the simulated outputs.

Enteric methane (CH) production attributable to beef cattle contributes to global greenhouse gas emissions. Reliably estimating this contribution requires extensive CH emission data from beef cattle under different management conditions worldwide. The objectives were to: 1) predict CH production (g d animal), yield [g (kg dry matter intake; DMI)] and intensity [g (kg average daily gain)] using an intercontinental database (data from Europe, North America, Brazil, Australia and South Korea); 2) assess the impact of geographic region, and of higher- and lower-forage diets. Linear models were developed by incrementally adding covariates. A K-fold cross-validation indicated that a CH production equation using only DMI that was fitted to all available data had a root mean square prediction error (RMSPE; % of observed mean) of 31.2%. Subsets containing data with ≥25% and ≤18% dietary forage contents had an RMSPE of 30.8 and 34.2%, with the all-data CH production equation, whereas these errors decreased to 29.3 and 28.4%, respectively, when using CH prediction equations fitted to these subsets. The RMSPE of the ≥25% forage subset further decreased to 24.7% when using multiple regression. Europe- and North America-specific subsets predicted by the best performing ≥25% forage multiple regression equation had RMSPE of 24.5 and 20.4%, whereas these errors were 24.5 and 20.0% with region-specific equations, respectively. The developed equations had less RMSPE than extant equations evaluated for all data (22.5 vs. 23.2%), for higher-forage (21.2 vs. 23.1%), but not for the lower-forage subsets (28.4 vs. 27.9%). Splitting the dataset by forage content did not improve CH yield or intensity predictions. Predicting beef cattle CH production using energy conversion factors, as applied by the Intergovernmental Panel on Climate Change, indicated that adequate forage content-based and region-specific energy conversion factors improve prediction accuracy and are preferred in national or global inventories., Authors gratefully acknowledge project funding from the USDA National Institute of Food and Agriculture Federal Appropriations under Project PEN 04539 and Accession number 1000803; the Joint Programming Initiative on Agriculture, Food Security and Climate Change (FACCE-JPI)’s ‘GLOBAL NETWORK’ project and the ‘Feeding and Nutrition Network’ (http://animalscience.psu.edu/fnn) of the Livestock Research Group within the Global Research Alliance for Agricultural Greenhouse Gases (www.globalresearchalliance.org); the Sesnon Endowed Chair program (UC Davis); the Swiss Federal Office of Agriculture, Berne, Switzerland; AHDB Beef and Lamb, the Scottish Government, Defra and the devolved administrations through the UK Agricultural Greenhouse Gas Inventory Research Platform; French National Research Agency through the FACCE-JPI program (ANR-13-JFAC-0003-01); the Cooperative Research Program for Agriculture Science, (Project No. PJ013448012018), RDA, Republic of Korea; the Australian Government Department of Agriculture, Fisheries and Forestry (Carbon Farming Futures Action on the Ground program; AOTGR2-0400); the financial support of the Reducing Emissions from Livestock Research Program, the National Livestock Methane Program, Meat and Livestock Australia, CSIRO and Ridley AgriProducts Pty, Ltd; the Institute of Science and Technology in Animal Science (INCTCA 465377/2014-9), the Department of Agriculture, Food and the Marine (DAFM), Ireland (AGRI-I project); European Commission through SMEthane (FP7‐SME‐262,270); Beef Cattle Research Council of the Canadian Cattlemen’s Association; the Cofund for Monitoring & Mitigation of Greenhouse Gases from Agri- and Silvi-culture (FACCE ERA-GAS)’s project Capturing Effects of Diet on Emissions from Ruminant Systems and the Dutch Ministry of Agriculture, Nature and Food Quality (AF-EU-18010 & BO-4400159-01).

A field study of methane emissions from wetlands reveals that more of the gas escapes through diffusive processes than was thought, mostly at night. Because methane is a greenhouse gas, the findings have implications for global warming.

De nombreux travaux ont été conduits au cours de ces dernières années afin de réduire l’excrétion d’azote, de phosphore, de cuivre, de zinc et de soufre chez le porc. Au-delà de la réduction des quantités excrétées, l’alimentation influence également la composition physico-chimique des déjections et le devenir des excrétas tout au long de la chaine de gestion des effluents. Les dispositifs expérimentaux disponibles à l’Inra et à l’Irstea et intégrés dans la plateforme Apivale permettent d’étudier finement ces phénomènes depuis l’excrétion par les animaux, en cours de stockage et jusqu’à la valorisation finale. Deux exemples illustrent ce type d’études.[br/] Influence de l’enrichissement en fibres des aliments sur les émissions d’ammoniac et de méthane[br/] L’incorporation dans l’aliment de coproduits riches en fibres s’accompagne d’une diminution de la digestibilité de la matière organique, de l’azote, du carbone et de l’énergie. Ce qui entraine une augmentation de la quantité de fèces et une réorientation de l’excrétion de l’azote vers les fèces au détriment de l’urine. Le pH des fèces, de l’urine et des lisiers est diminué, conjointement à l’accroissement de la teneur en acides gras volatils et à la réduction de la teneur en ammoniac. Ces différentes modifications de composition des excrétas entrainent une réduction importante de la volatilisation d’ammoniac (de -19 à -33% selon les régimes). Le potentiel d’émission de méthane par porc et par jour est par contre fortement augmenté (de +50 à +66% selon les régimes) surtout du fait de l’augmentation de la quantité de matière organique excrétée. Ces résultats indiquent clairement que l’ajout dans l’alimentation de coproduits riches en fibres diminue la volatilisation de l’ammoniac mais augmente la production de méthane. C’est un avantage lorsque les effluents sont méthanisés, mais plutôt un problème lorsqu’ils sont simplement stockés puis épandus. En combinant la séparation de phase et l’ajout de fibres, il est ainsi possible de doubler la production de méthane par porc.[br/] Impact de l’alimentation sur l’excrétion de soufre et le potentiel de production d’H2S dans les digesteurs de méthanisation[br/] La teneur en soufre des aliments est susceptible de varier assez fortement selon les matières premières utilisées. Avec des régimes dont la teneur en protéines varie ou si l’on remplace partiellement du tourteau de soja et du blé par des drêches de blé, des pulpes de betteraves et du tourteau de colza, l’apport de soufre varie entre 3,1 et 8,3 g S/porc/jour, et l’excrétion entre 1,5 à 6,9 g S/porc/jour. Avec 73% du total, l’excrétion urinaire constitue la principale voie d’excrétion et quel que soit le régime. Les sulfates représentent 90% de l’excrétion totale. L’alimentation et la séparation de phase constituent donc des voies intéressantes pour maîtriser la production de H2S dans les digesteurs de méthanisation.

Enteric methane emission by ruminants fed forages is highly variable and depends on forage composition, intake and digestibility. In addition, plant secondary compounds such as tannins have antimethanogenic properties; however, the mitigating effect of tannins on CH4 is inconsistent. A meta-analysis approach was used to compare the effects of different forages, supplemented or not with tannins, fed to ruminants on CH4 emission. Tannin content (TAN, condensed or hydrolysable), averaged 35.6 (sd =53.0) g/kg DM and varied from 0 to 199 g/kg DM, for 19 experiments and 53 treatments. Methane production, expressed per kg of digestible OMI (g/kg DOMI) significantly decreased when feeding level (FL, calculated as DM intake % liveweight) increased and when NDF content of the forage decreased. Moreover, tannins content (g/kg DM) decreasing effect on methane emission was significant. The effect of tannins for mitigating CH4 emission is in agreement with previous studies, but in the present study the impact of tannins was lower, probably due to accounting for decreasing effect of FL and increasing effect of NDF effects in the equation and to small relations between these factors.

La mobilité des systèmes d’élevage ovins utilisateurs d’une grande variété de ressources pâturées en Provence : impacts sur le bilan énergétique et les émissions de méthane. Réseau prairies – Symposium 2017

[object Object]Efforts to reduce the carbon footprint of milk produc- tion through selection and management of low-emitting cows require accurate and large-scale measurements of methane (CH 4 ) emissions from individual cows. Several techniques have been developed to measure CH 4 in a re- search setting but most are not suitable for large-scale recording on farm. Several groups have explored prox- ies (i.e., indicators or indirect traits) for CH 4 ; ideally these should be accurate, inexpensive, and amenable to being recorded individually on a large scale. This review (1) systematically describes the biological basis of current potential CH 4 proxies for dairy cattle; (2) assesses the accuracy and predictive power of single proxies and determines the added value of combining proxies; (3) provides a critical evaluation of the relative merit of the main proxies in terms of their simplicity, cost, accuracy, invasiveness, and throughput; and (4) discusses their suitability as selection traits. The prox- ies range from simple and low-cost measurements such as body weight and high-throughput milk mid-infrared spectroscopy (MIR) to more challenging measures such as rumen morphology, rumen metabolites, or microbi- ome profiling. Proxies based on rumen samples are gen- erally poor to moderately accurate predictors of CH 4 , and are costly and difficult to measure routinely on- farm. Proxies related to body weight or milk yield and composition, on the other hand, are relatively simple, inexpensive, and high throughput, and are easier to implement in practice. In particular, milk MIR, along with covariates such as lactation stage, are a promising option for prediction of CH 4 emission in dairy cows. No single proxy was found to accurately predict CH 4 , and combinations of 2 or more proxies are likely to be a better solution. Combining proxies can increase the accuracy of predictions by 15 to 35%, mainly because different proxies describe independent sources of varia- tion in CH 4 and one proxy can correct for shortcomings in the other(s). The most important applications of CH 4 proxies are in dairy cattle management and breed- ing for lower environmental impact. When breeding for traits of lower environmental impact, single or multiple proxies can be used as indirect criteria for the breeding objective, but care should be taken to avoid unfavor- able correlated responses. Finally, although combina- tions of proxies appear to provide the most accurate estimates of CH 4 , the greatest limitation today is the lack of robustness in their general applicability. Future efforts should therefore be directed toward developing combinations of proxies that are robust and applicable across diverse production systems and environments.

Nutritional policies recommend that animal products should be made to contain more polyunsaturated FA, especially n-3 FA. This means finding ways to limit ruminal lipolysis and/or biohydrogenation. In pursuit of this goal, we performed an in vitro study to test the ability of four feed additives, typically used for other purposes, to reduce ruminal biohydrogenation of a linolenic acid-rich substrate. The four additives tested were cinnamon essential oil, brown algae (Ascophyllum nodosum), synthetic vitamin E, and garlic essential oil. The first three additives had no effect on ruminal fermentation and biohydrogenation. Garlic essential oil led to a decrease in methane production (P

The main objective of this work was to develop a controller for biogas production in continuous anaerobic fixed-bed reactors, which used effluent total volatile fatty acids (VFA) concentration as control input in order to prevent process acidification at closed loop. To this aim, a fuzzy-logic-based control system was developed, tuned and validated in an anaerobic fixed-bed reactor at pilot scale that treated industrial winery wastewater. The proposed controller varied the flow rate of wastewater entering the system as a function of the gaseous outflow rate of methane and VFA concentration. Simulation results show that the proposed controller is capable to achieve great process stability even when operating at high VFA concentrations. Pilot results showed the potential of this control approach to maintain the process working properly under similar conditions to the ones expected at full-scale plants.

peer-reviewed Microorganisms in the digestive tract of ruminants differ in their functionality and ability to use feed constituents. While cecal microbiota play an important role in post-rumen fermentation of residual substrates undigested in the rumen, limited knowledge exists regarding its structure and function. In this trial we investigated the effect of dietary supplementation with linseed oil and nitrate on methane emissions and on the structure of ruminal and cecal microbiota of growing bulls. Animals were allocated to either a CTL (control) or LINNIT (CTL supplemented with 1.9% linseed and 1.0% nitrates) diet. Methane emissions were measured using the GreenFeed system. Microbial diversity was assessed using amplicon sequencing of microbial genomic DNA. Additionally, total RNA was extracted from ruminal contents and functional mcrA and mtt genes were targeted in amplicon sequencing approach to explore the diversity of functional gene expression in methanogens. LINNIT had no effect on methane yield (g/kg DMI) even though it decreased methane production by 9% (g/day; P < 0.05). Methanobrevibacter- and Methanomassiliicoccaceae-related OTUs were more abundant in cecum (72 and 24%) compared to rumen (60 and 11%) irrespective of the diet (P < 0.05). Feeding LINNIT reduced the relative abundance of Methanomassiliicoccaceae mcrA cDNA reads in the rumen. Principal component analysis revealed significant differences in taxonomic composition and abundance of bacterial communities between rumen and cecum. Treatment decreased the relative abundance of a few Ruminococcaceae genera, without affecting global bacterial community structure. Our research confirms a high level of heterogeneity in species composition of microbial consortia in the main gastrointestinal compartments where feed is fermented in ruminants. There was a parallel between the lack of effect of LINNIT on ruminal and cecal microbial community structure and functions on one side and methane emission changes on the other. These results suggest that the sequencing strategy used here to study microbial diversity and function accurately reflected the absence of effect on methane phenotypes in bulls treated with linseed plus nitrate. This experiment is a part of a large collaborative project led by INRA granted by 11 companies: Adisseo France SAS, Agrial, Apis Gene, Deltavit, DSM Nutritional Products AG, Institut de l’Elevage, Lallemand, Moy Park Beef Orléans, Neovia, Techna France Nutrition, Valorex. This project aims to reduce enteric methane emission by nutrition. MP was the recipient of a PHC Ulysses travel scholarship to Ireland, provided by the French ministry of Foreign Affairs and International Development (Ministères des Affaires Etrangères et du Développement International, MAEDI) and the ministry of National Education, Higher Education, and Research (Ministère de l’Education Nationale, de l’Enseignement Supérieur et de la Recherche, MENESR). EM was the recipient of a FACCE-JPI scholarship.

The effect of tea saponin supplementation in the ruminant diet on methane emissions, rumen fermentation, and digestive processes is still under debate. The objective of this study was to assess the effect of this plant extract on methanogenesis, total-tract digestibility, and lactating performances of dairy cows. The work included 2 independent and successive experiments. First, the effect of 7 tea saponin doses (from 0 to 0.50 g/L) on methane emissions and protozoa concentrations was tested in 2 repeated in vitro batch culture incubations using bovine rumen contents as inoculum and a cereal mixture as substrate. After 18 h of incubation, total gas production and composition as well as rumen fermentation parameters and protozoa concentration were analyzed. Increasing dosage of the plant extract reduced methane production and protozoa concentration, with a maximum reduction of 29% for CH4 (mL/g of substrate) and 51% for protozoa (10(5)/mL). Tea saponin did not affect volatile fatty acids concentration, but marginally decreased total gas production by 5% at the highest dose. Second, a 2-period crossover design experiment was carried out with 8 lactating dairy cows fed a basal diet (54% corn silage, 6% hay, and 40% pelleted concentrates on a dry matter basis) without (control) or with 0.52% tea saponin (TSP). Each experimental period lasted 5 wk. Animals were fed ad libitum during the first 3 wk of the period (wk 1, 2, and 3) and restricted (95% of ad libitum intake) during the last 2 wk (wk 4 and 5). Intake and milk production were recorded daily. Methane emissions were quantified using open chambers (2 d, wk 4). Total-tract digestibility and nitrogen balance were determined from total feces and urine collected separately (5 d, wk 5). Rumen fermentation parameters and protozoa concentration were analyzed from samples taken after morning feeding (1 d, wk 5). Milk production, dry matter intake, and feed-efficiency were reduced with TSP (-18, -12, and -8%, respectively). As daily methane production (g/d) was not affected, methane emissions (g/kg of dry matter intake) increased by 14% with TSP. Total-tract digestibility and nitrogen balance were similar between diets, except for acid detergent fiber digestibility, which tended to be improved with TSP (+4 percentage units). Rumen fermentation parameters and protozoa concentration were relatively unchanged by diets. Under the conditions of this experiment, tea saponin is not efficient to reduce methane emissions from dairy cows.

Soil gas fluxes depend on soil gas concentrations and physical properties of a soil. Taking soil samples for physical analysis into the laboratory strongly modifies soil gas concentrations and also cuts roots that sustain the activity in the rhizosphere. Since microbial processes interact with gas concentrations in soil, we need to study gas transport and production in situ. We developed a method to monitor the transport and production and consumption of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in soils in situ in a two dimensional (2D) profile using tetrafluoromethane (CF4) and sulfur hexafluoride (SF6) as tracer gases and Finite Element Modeling of soil gas transport. Continuous injection of the inert tracer gases and 2D gas sampling in a soil profile allowed for inverse modeling of the 2D profile of soil gas diffusivity. In a second step, the 2D profiles of the production and consumption of CO2, CH4, and N2O were inversely determined. Soil gas concentrations were monitored in a Scots pine stand in South-West Germany during a rain-free week in the fall. The 2D relative (so as to be independent of gas species) soil gas diffusivity profile showed large horizontal variability. Relative soil gas diffusivity was found to be anisotropic with the vertical direction greater by a factor of 1.26. Topsoil moisture decreased slowly over time resulting in an increase in relative soil gas diffusivity. The soil was found to be a source of CO2, and a net sink of CH4 and N2O, with the highest production (CO2) and consumption (CH4, N2O) occurring in the topsoil. The gas concentration and production profiles of CO2 were nearly horizontally homogenous, while those for CH4 showed larger horizontal differences. Net consumption of CH4 and net production of CO2 both increased as the soil dried. This occurred despite reverse trends for these variables in the topsoil (0–8 cm depth) which were more than offset by the underlying soil becoming more active. Sensitivity tests showed that the determination of 2D profiles of soil gas diffusivity and production and consumption of CO2 and CH4 were more reliable than the estimates for N2O because the magnitudes of these for N2O were very low. Our method represents a useful tool for the analyses of soil gas flux heterogeneities and associated microbial processes within soil profiles.

Epub 2017 Aug 15; The combination of linseed and nitrate is known to decrease enteric methane emission in dairy cows but few studies have been carried out in fattening cattle for animal liveweight gain, enteric methane emission, animal health and presence of residues in beef products. To address this gap, 16 young bulls received a control (C) diet between weaning at 9 months and 14 months, then were split into two groups of eight balanced on feed intake, BW gain and methane emission to receive either the C diet or a diet moderately supplemented with extruded linseed and calcium nitrate (LN) for 2 months before being slaughtered. On a dry matter (DM) basis, the C diet contained 70% baled grass silage and 30% concentrate mainly made of maize, wheat and rapeseed meal. In the LN diet, rapeseed meal and a fraction of cereals were replaced by 35% extruded linseed and 6% calcium nitrate; linseed fatty acids and nitrate supply in the LN diet were 1.9% and 1.0%, respectively. Methane emission was measured continuously using the GreenFeed system. Methaemoglobin was determined every week in peripheral blood from bulls receiving the LN diet. Nitrate and nitrite concentrations were determined in rumen, liver and tongue sampled at slaughter. Dry matter intake tended to be lower for LN diet (P=0.10). Body weight gain was lower for LN diet (P=0.01; 1.60 and 1.26 kg/day for C and LN diet, respectively). Daily methane emission was 9% lower (P

The biomass replaces the petroleum as energy is involved in energy transformations. There are two grade transformations from the wheat which are the fuel ethanol and the marsh gas ferment. The study on their transformation mechanisms and how to improve their energy efficiency will be benefit for both the academic and practical significance. Studies have shown that at least 67.05% wheat energy changes into fuel ethanol and at least 15.46% the rest of accessory substance alcohol lees energy changes into marsh gas. The total energy transformation amount is not less than 82.51%.The ratio of the wheat fuel ethanol input to output is 1.04, and NEV is 1167 MJ. The result shows the values of energy gain are positive.

Wetlands cover only a small fraction of the Earth’s land surface, but have a disproportionately large influence on global climate. Low oxygen conditions in wetland soils slows down decomposition, leading to net carbon dioxide sequestration over long timescales, while also favoring the production of redox sensitive gases such as nitrous oxide and methane. Freshwater marshes in particular sustain large exchanges of greenhouse gases under temperate or tropical climates and favorable nutrient regimes, yet have rarely been studied, leading to poor constraints on the magnitude of marsh gas sources, and the biogeochemical drivers of flux variability.The Sacramento-San Joaquin Delta in California was once a great expanse of tidal and freshwater marshes but underwent drainage for agriculture during the last two centuries. The resulting landscape is unsustainable with extreme rates of land subsidence and oxidation of peat soils lowering the surface elevation of much of the Delta below sea level. Wetland restoration has been proposed as a means to slow further subsidence and rebuild peat however the balance of greenhouse gas exchange in these novel ecosystems is still poorly described.In this dissertation I first explore oxygen availability as a control on the composition and magnitude of greenhouse gas emissions from drained wetland soils. In two separate experiments I quantify both the temporal dynamics of greenhouse gas emission and the kinetic sensitivity of gas production to a wide range of oxygen concentrations. This work demonstrated the very high sensitivity of carbon dioxide, methane, and nitrous oxide production to oxygen availability, in carbon rich wetland soils. I also found the temporal dynamics of gas production to follow a sequence predicted by thermodynamics and observed spatially in other soil or sediment systems.In the latter part of my dissertation I conduct two field studies to quantify greenhouse gas exchange and understand the carbon sources for decomposition in a 1 km2 restored wetland in the Sacramento Delta. By coupling flux measurements at multiple-scales with remote sensing imagery I showed that large methane emissions produce an overall climate warming effect from the wetland for the next several centuries, despite relatively high productivity. I also used radiocarbon analyses of wetland sediment carbon dioxide and methane to show that both bulk peat and recently fixed carbon contribute to decomposition in the wetland, and that their relative importance is regulated by proximity to, and the phenological cycles of, emergent vegetation.

Simulation of enteric methane emissions from individual beef cattle in tropical pastures of improving quality: a case study with the model RUMINANT

China has remained a predominantly agricultural country since the Chinese civilization was born 6000 years ago. Since 2000, Chinese farmers have already had the pristine idea of the circular economy. They have fermented feces, garbage, crop stalks, green manure and biogas slurry etc and reused them in agricultural production. Farmers’ livestock and poultry, fish, mulberry, marsh gas, vegetable plots, farmland, fish ponds, wood and villages have constituted the prime ecosystem featuring circular economy development. “Mulberry fish pond complex” and “rice-duck farming” have been summarized as the pristine models of the circular economy development of China’s agriculture.

Straw biomass is a clean and recyclable energy resource. It has a lot of advantages, such as low content of sulphur, nitrogen, low pollution and so on. At present, straw biomass has been researched and used at home and abroad, mainly in the production of diesel oil by cracking, the production of ethanol by hydrolysis, fuel methanol, the production of marsh gas by anaerobic digestion, solidify biological briquettes, electricity production from crop stalks and hydrogen production from biomass, etc. This aims of our article is the features of all technologies and the existing problems, which suggests the future researches that the skills of straw biomass should be strengthened, and makes a prediction at its application prospects.

The ability of marshes and forested wetlands to provide environmental services (water retention in soil and carbon storage) was evaluated at three locations along the coast of Veracruz, Mexico. Hydro-periods were obtained for the different vegetation communities of marshes and forested wetlands. Total organic carbon contents were 26.2% in Pachira swamp, 23.1% in Ficus swamp and 11.2% in marsh soils. The largest values of hydraulically active pore space were observed for marshes (0.79 cm3 cm-3), and the lowest in forested wetlands (0.57 cm3 cm-3). Soil water holding capacity ranged from 556 to 834 L m-2 for swamp areas and from 687 to 880 L m-2 for marshes. The thickness of soil organic layers in the wetland studied had a major control on soil water storage. This suggests that a vast amount of rain water could be retained in the soil. The results indicate that both swamps and marshes play important roles in their capacities to retain water and sequester carbon, although there were no significant d...

The main purpose that should be put in the first place on residential constructions in the rural areas is how to guide the consumers to build residential buildings that are energy effective, comfortable, cost effective, and with construction techniques that are appropriate for the local conditions. Before investigating residential buildings that are suitable for local conditions, we have to discover the local economic status and their living habit in depth. This article puts emphasis on to survey the relationship between dwelling habits and energy consumption in the rural areas, also, space heating and cooling method, the use of solar energy, marsh gas and any other renewable sources of energy, as well as the thermal environment of residential buildings are investigated and analyzed. we conclude that, in the rim of Xi'an city, most of the fuel sources for space heating in winter used in the rural areas are fireweed and cornstock. Most of the energy sources are crops waste materials that are not environmental friendly, thus, it's necessary to popularize the use of solar energy and marsh gas.

This paper thoroughly analyzed the popularization of the usage of marsh gas in En-Shi City of China, and the survey from farmers also well proved the effectiveness of marsh gas. Therefore, the conclusion is that the utilization of marsh gas can improve the farmer's living level and has positive effects to the protection of environment as well as the prosperity of the agriculture and the rural areas, besides, farmers are also very satisfied. We can assure that the usage of the low cost, small size and distributed bio-energy will be a very promising way to the continuous development of the rural areas.

The purposes of this study are to look into the actuality of rural residential energy consumption in Hunan province, China, to improve energy utilization structure, and to protect the environment. ...

Marsh gas is a danger for tunnelling through soils in Shanghai. Predrilling can assess the hazard and help to vent the gas. Additional measures include tunneling with an airproof shield, adequate ventilation, special precautions against ignition and education of the workers.

Gases are produced from wetlands when plant biomass is degraded by microbial consortia, producing carbon dioxide aerobically and methane when oxygen is lacking. In anaerobic waterlogged situations, such as the catotelm of ombrotrophic bogs, this methane forms minute gas bubbles that severely reduce the hydraulic conductivity and hence the degradation of biomass due to the lack of nutrients. The bogs thus become carbon sinks, formed from the partially degraded biomass that accumulates as peat. The results of an investigation of an ombrotrophic bog, Mer Bleue, Ontario, Canada are summarized here, and the effects that climate change may have on such bogs are discussed. Any change of the water table in wetlands will have a substantial effect upon their ecology. If the water table should fall allowing bogs to become aerobic, most of the accumulated biomass carbon could be returned to the atmosphere by degradation to carbon dioxide, and as well, methane entrapped within the matrix would be released directly to the atmosphere. If on the other hand, the bogs are flooded, then the entrapped bubbles will coalesce allowing the gas to escape to the atmosphere, while at the same time the degradation of the peat will be enhanced.

International audience; A model has been developed to predict pig manure evolution (mass, dry and organic matter, N, P, K, Cu and Zn contents) and related gaseous emissions (methane (CH4), nitrous oxide (N2O) and ammonia (NH3)) from pig excreta up to manure stored before spreading. This model forms part of a more comprehensive model including the prediction of pig excretion. The model simulates contrasted management systems, including different options for housing (slatted floor or deep litter), outside storage of manure and treatment (anaerobic digestion, biological N removal processes, slurry composting (SC) with straw and solid manure composting). Farmer practices and climatic conditions, which have significant effects on gaseous emissions within each option, have also been identified. The quantification of their effects was based on expert judgement from literature and local experiments, relations from mechanistic models or simple emission factors, depending on existing knowledge. The model helps to identify relative advantages and weaknesses for each system. For example, deep-litter with standard management practices is associated with high-greenhouse gas (GHG) production (+125% compared to slatted floor) and SC on straw is associated with high NH3 emission (+15% compared to slatted floor). Another important result from model building and first simulations is that farmer practices and the climate induce an intra-system (for a given infrastructure) variability of NH3 and GHG emissions nearly as high as inter-system variability. For example, in deep-litter housing systems, NH3 and N2O emissions from animal housing may vary between 6% and 53%, and between 1% and 19% of total N excreted, respectively Thus, the model could be useful to identify and quantify improvement margins on farms, more precisely or more easily than current methodologies.

The purposes of this study were 1) to assess the effects of 3 high-concentrate diets on enteric CH(4) production, total tract digestibility, and rumen fermentation of beef cattle, and 2) to evaluate, by life cycle assessment, the potential effects of these feeding systems on the environment. Six bulls (age of 12.4 mo and BW of 417 kg at midexperiment) of the Blond d'Aquitaine breed were assigned to 3 dietary treatments in a replicated 3 x 3 Latin square design. Diets consisted of 1) 49% natural grassland hay, 41% ground corn grain, and 10% soybean meal (hay); 2) 63% corn silage, 21% ground corn grain, and 16% soybean meal (CS); and 3) 70% ground corn grain, 16% soybean meal, and 14% wheat straw (CG). Daily CH(4) emission (g/d), measured using the sulfur hexafluoride tracer technique, was similar for the hay and CS diets and was 56% greater than for the CG diet (P < 0.001). This difference between diets was maintained when CH(4) output was expressed by unit of feed intake (P < 0.001) or digested feed (P < 0.001). Gross energy intake loss as CH(4) averaged 6.9% for the hay and CS diets and 3.2% for the CG diet (P < 0.001). Organic matter intake and GE intake did not differ between diets. Organic matter digestibility was less for the hay diet than for the CS and CG diets (P = 0.008). Digestibility of NDF was greatest for the hay diet, intermediate for the CS diet, and least for the CG diet (P = 0.02), with ADF digestibility being similar between the hay and CS diets and greater than for the CG diet (P < 0.001). The rumen pH at 5 h postfeeding was less for animals fed the CG diet compared with those fed the other 2 diets (on average, 5.1 vs. 5.9, respectively; P < 0.001). Total CH(4) emission (enteric + manure) was least for the CG diet, whereas N(2)O and CO(2) emissions were greatest for the CG diet. Total greenhouse gas emissions were least for the CG diet when C sequestration by grasslands was not taken into account.

Rock desertified region is difficult for forestations and is the key area for eco-environment treatment. To speed up the comprehensive treatment of rocky desertification, several anti-rock desertification management models were implemented in Dingtan region, located in the right bank of Huajiang Gorge in the Beipanjiang townships. These models, including “bamboo leaf prickly ash - marsh gas” (model one), “amomum villosum -breed pigs -marsh gas” (model two), “traditional grain and economic crop (corn, penut) -amomum villosum or bamboo leaf prickly ash” (model three) and “traditional Agricultural Cropsand Wild Tall Bush” (model four), were studied over a long period of time. The eco-economic effects, potential and shortcomings of the above mentioned models are compared. It is demonstrated that model one and model two are of good economic effect, but model three is of better ecological effect. Finally, some solutions based on the shortcomings of these models were also brought out.

As a kind of high efficient equipment of waster treatment, Up-flow Anaerobic sludge Blanket(UASB)has many advantages, such as effluent quality, steady operation,broad application on treatment high concentration organic wasters. Due to the high COD consistency of the wastewater from starch production, the expense of the treatment are always very high. The paper started with the advantages of Up-flow Anaerobic Sludge Bed(UASB), the feasible of generating marsh gas from UASB was analyzed and the utilization condition and use of marsh gas were discussed. At last, it pointed that the UASB could be used comprehensively to treat high organic sewage. The results of the treatment's running shows that the treatment of wastewater from starch production by UASB possess the high COD removal rate and it is a low cost and feasible process. It proved that the treatment process can be widely occupied in the treatment of vastewater from the industry of bio-chemistry. It will bring great economical, social and environmental benefit.

Swamps are wooded wetlands and include forested and shrub wetlands. Swamp is used in many European and African countries and elsewhere to refer to a wetland that is dominated by tall emergent plants, whether woody or herbaceous. The herbaceous ‘swamps’ under those systems of classification are referred to as marshes in this encyclopedia and are covered elsewhere. The Sudd swamps in Africa, for example, are marshes for the most part following the definition above. Swamps or wooded wetlands occur on hydric soils, are flooded or saturated for part of the growing season in most years, and support a canopy of trees and/or shrubs that cover 25–30% or more of the wetland; wetland trees or shrubs are adapted for wetland life or can tolerate periods of inundation. Adaptations of trees and shrubs for wetland life often include development of aerenchyma tissue that ‘form channels’ that allow gases to diffuse or be transported by differences in canopy and root temperatures and concentrations from aerial parts of the plant to and from the roots. Another adaptation in some species includes adventitious roots that extend from the aerial parts of the plant to or into the sediment or below the water surface and support the plant (stilt roots) and/or function in transporting oxygen to underground/underwater roots via lenticels (pores) that allow gases to enter and exit the aerial root and be transported to and from the underground roots via aerenchyma tissue. Another adaptation is the development of pneumatophores or roots that extend from the sediment to above the water surface and also function to allow gases to exchange between the atmosphere and roots buried in sediments and/or help to hold the tree or shrub in place. Seed dispersal in swamps include dispersal by a variety of birds, mammals, fish (especially in the tropics), and other animals, and by wind and water. Forested swamps are dominated by trees that are 6 m tall or taller and may include one or more shrub layers and an herbaceous layer of plants. Shrub swamps are dominated by woody plants that are less than 6 m tall. Swamps are found on nearly every continent around the world and in all wetland habitats including in and along the margins of lakes and streams, in floodplains and deltas, in isolated depressions, in seepage areas on hill slopes, and on waterlogged soils on flats. Swamps that are underlain by peat deposits include boreal forested and shrub bogs and fens and tropical forests on waterlogged soils. Nonpeat swamps are estimated by one author to cover up to 15% of the world's wetlands. It is estimated that peat swamps cover at least that much land surface, although data on them are limited. Major peat swamp areas include swamps in the boreal and Northern Temperate Zones of Canada, Russia, Alaska, and Scandinavia. Tropical peat swamps occur widely on waterlogged soils in southeast Asia with smaller areas in Africa and elsewhere. It is estimated that swamps (wooded wetlands) cover about 30% or more of all wetlands and occupy 2% or more of land globally. This is a conservative estimate. Swamps range in productivity from 200 to 1800 g m−2 yr−1 depending on flow and hydroperiod. They supply a multitude of ecosystems services to humans that have been estimated to be as high as $7000 per hectare annually. They also support a high diversity of organisms including millions of birds, fish, crocodilians, snakes, turtles, and amphibians.

This paper presents a new model on synthetic effects on oil-generation in a waterlogged and closed system. It is suggested based on information about oil in high pressure layers (including gas dissolved in oil), marsh gas and its fermentative solution, fermentation processes and mechanisms, gaseous hydrocarbons of carbonate rocks by acid treatment, oil-field water, recent and ancient sediments, and simulation experiments of artificial marsh gas and biological action. The model differs completely from the theory of oil-generation by thermal degradation of kerogen but stresses the synthetic effects of oil-generation in special waterlogged and closed geological systems, the importance of pressure in oil-forming processes, and direct oil generation by micro-organisms. Oil generated directly by micro-organisms is a particular biochemical reaction. Another feature of this model is that generation, migration and accumulation of petroleum are considered as a whole.

Au cours des dernières décennies, plusieurs publications ont concerné les mesures du métabolisme énergétique et de la production de CH4 par les chèvres. Ces données ont été rassemblées dans une base dans le but d’actualiser nos connaissances dans ces domaines par une synthèse quantitative par méta-analyse.