Agricultural Methanogenesis

2018 ◽  
Author(s):  
Alexander N. Hristov
Keyword(s):  
Animal Manure ◽  
Methane Emissions ◽  
Rice Cultivation ◽  
Mitigation Strategies ◽  
Manure Management ◽  
Ruminal Fermentation ◽  
Root Cells ◽  
Ambient Temperatures ◽  
Dietary Nutrients ◽  
Enteric Methane

Agriculture is a significant source of methane, contributing about 12% of the global anthropogenic methane emissions. Major sources of methane from agricultural activities are fermentation in the reticulo-rumen of ruminant animals (i.e., enteric methane), fermentation in animal manure, and rice cultivation. Enteric methane is the largest agricultural source of methane and is mainly controlled by feed dry matter intake and composition of the animal diet (i.e., fiber, starch, lipids). Processes that lead to generation of methane from animal manure are similar to those taking place in the reticulo-rumen. Methane emissions from manure, however, are greatly influenced by factors such as manure management system and ambient temperature. Systems that handle manure as a liquid generate much more methane than systems in which manure is handled as a solid. Low ambient temperatures drastically decrease methane emissions from manure. Once applied to soil, animal manure does not generate significant amounts of methane. Globally, methane emissions from rice cultivation represent about 10% of the total agricultural greenhouse gas emissions. In the rice plant, methane dissolves in the soil water surrounding the roots, diffuses into the cell-wall water of the root cells, and is eventually released through the micropores in the leaves. Various strategies have been explored to mitigate agricultural methane emissions. Animal nutrition, including balancing dietary nutrients and replacement of fiber with starch or lipids; alternative sinks for hydrogen; manipulation of ruminal fermentation; and direct inhibition of methanogenesis have been shown to effectively decrease enteric methane emissions. Manure management solutions include solid-liquid separation, manure covers, flaring of generated methane, acidification and cooling of manure, and decreasing manure storage time before soil application. There are also effective mitigation strategies for rice that can be categorized broadly into selection of rice cultivars, water regime, and fertilization. Alternate wetting and drying and mid-season drainage of rice paddies have been shown to be very effective practices for mitigating methane emissions from rice production.

scholarly journals PSII-17 Program Chair Poster Pick: Effect of ruminal protozoa on methane emissions in ruminants – a meta-analysis

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 397-398
Author(s):  
Xiaoxia Dai ◽  
Kenneth Kalscheur ◽  
Pekka Huhtanen ◽  
Antonio Faciola
Keyword(s):  
Dairy Cows ◽  
Meta Analysis ◽  
Random Effect ◽  
Negative Relationship ◽  
Small Ruminants ◽  
Methane Emissions ◽  
Mitigation Strategies ◽  
Positive Relationships ◽  
Ruminal Fermentation ◽  
The Relationship

Abstract The effects of ruminal protozoa (RP) concentration on methane emissions from ruminants were evaluated in a meta-analysis using 67 publications reporting data from 85 in vivo experiments. Experiments included in the database reported methane emissions (g/kg DMI) and RP (log10 cells/mL) from the same group of animals. Quantitative data including diet chemical composition, ruminal fermentation, total tract digestibility, and milk production; and qualitative information including methane mitigation strategies, animal type, and methane measurement methods were also collected. The studies were conducted in dairy cows (51%), beef steers (32%) and small ruminants (32%). 70% of the studies reported a reduction in methane emissions. Supplemental lipids reduced methane emissions 95% of the time. The relationship between methane emissions and RP concentration was evaluated as a random coefficient model with the experiment as a random effect and weighted by the inverse pooled SEM squared, including the possibility of covariance between the slope and the intercept. A quadratic effect of RP concentration on methane emissions was detected: CH4= -28.8 + 12.2 × RP-0.64 × RP2. To detect potential interfering factors in the relationship, the influence of several qualitative and quantitative factors were separately tested. Acetate, butyrate, and isobutyrate molar proportions had positive relationships with methane emissions and influenced the relationship between RP concentration and methane emissions, where the presence of ruminal fermentation variables reduced the effects of RP concentration in methane emissions. Total tract digestibility of DM, OM, and CP had negative relationships while NDF digestibility had a positive relationship with methane emissions; however, they only changed the magnitude of intercept and slope of RP and RP2 for the relationship. For dairy cows, milk fat and protein concentrations had positive relationships and milk yield had a negative relationship with methane emissions and changed the magnitude of intercept and slope of RP and RP2 for the relationship.

Effects of mineral salt supplement on enteric methane emissions, ruminal fermentation and methanogen community of lactating cows

2016 ◽  
Vol 88 (8) ◽  
pp. 1049-1057 ◽  
Author(s):  
Xiaohua Li ◽  
Chong Liu ◽  
Yongxing Chen ◽  
Rongguang Shi ◽  
Zhenhua Cheng ◽  
...  
Keyword(s):  
Methane Emissions ◽  
Mineral Salt ◽  
Ruminal Fermentation ◽  
Lactating Cows ◽  
Enteric Methane ◽  
Methanogen Community ◽  
Enteric Methane Emissions

Mitigation strategies to reduce enteric methane emissions from dairy cows: Update review

2004 ◽  
Vol 84 (3) ◽  
pp. 319-335 ◽  
Author(s):  
D. Boadi ◽  
C. Benchaar ◽  
J. Chiquette ◽  
D. Massé
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
Greenhouse Gas ◽  
Management Practices ◽  
Genetic Selection ◽  
Mitigation Strategies ◽  
Ruminal Fermentation ◽  
Enteric Methane ◽  
Dietary Strategies

Enteric methane (CH4) emission is a major contributor to Canadian greenhouse gas emissions, and also a loss of feed energy during production. The objective of this paper is to provide an update on current management practices and new dietary strategies recently proposed to reduce CH4 emissions from ruminants. Existing mitigation strategies for dairy, e.g., the addition of ionophores, fats, use of high-quality forages, and increased use of grains, have been well researched and applied. These nutritional changes reduce CH4 emissions by manipulating ruminal fermentation, directly inhibiting methanogens and protozoa, or by diverting hydrogen ions away from methanogens. Current literature has identified new CH4 mitigation options. These include the addition of probiotics, acetogens, bacteriocins, archaeal viruses, organic acids, plant extracts (e.g., essential oils) to the diet, as well as immunization, and genetic selection of cows. These new strategies are promising, but more research is needed to validate these approaches and to assess in vivo their effectiveness in reducing CH4 production by dairy cows. It is also important to evaluate CH4 mitigation strategies in terms of the total greenhouse gas budget and to consider the cost associated with the various strategies. More basic understanding of the natural differences in digestion efficiencies among animals as well as a better knowledge of methanogens and their interaction with other organisms in the rumen would enable us to exploit the potential of some of the new CH4 mitigation strategies for dairy cattle production. Key words: Enteric methane, dairy cattle, mitigation

scholarly journals Opportunities for reducing environmental emissions from forage-based dairy farms

2013 ◽  
Vol 22 (1) ◽  
pp. 93-107 ◽  
Author(s):  
Tom Misselbrook ◽  
Agustin Del Prado ◽  
David Chadwick
Keyword(s):  
Nitrous Oxide ◽  
Methane Emissions ◽  
Mitigation Strategies ◽  
Mitigation Measures ◽  
Scale Model ◽  
Nitrous Oxide Emissions ◽  
Manure Management ◽  
Nitrification Inhibitors ◽  
Forage Crops ◽  
Enteric Fermentation

Modern dairy production is inevitably associated with impacts to the environment and the challenge for the industry today is to increase production to meet growing global demand while minimising emissions to the environment. Negative environmental impacts include gaseous emissions to the atmosphere, of ammonia from livestock manure and fertiliser use, of methane from enteric fermentation and manure management, and of nitrous oxide from nitrogen applications to soils and from manure management. Emissions to water include nitrate, ammonium, phosphorus, sediment, pathogens and organic matter, deriving from nutrient applications to forage crops and/or the management of grazing livestock. This paper reviews the sources and impacts of such emissions in the context of a forage-based dairy farm and considers a number of potential mitigation strategies, giving some examples using the farm-scale model SIMSDAIRY. Most of the mitigation measures discussed are associated with systemic improvements in the efficiency of production in dairy systems. Important examples of mitigations include: improvements to dairy herd fertility, that can reduce methane and ammonia emissions by up to 24 and 17%, respectively; diet modification such as the use of high sugar grasses for grazing, which are associated with reductions in cattle N excretion of up to 20% (and therefore lower N losses to the environment) and potentially lower methane emissions, or reducing the crude protein content of the dairy cow diet through use of maize silage to reduce N excretion and methane emissions; the use of nitrification inhibitors with fertiliser and slurry applications to reduce nitrous oxide emissions and nitrate leaching by up to 50%. Much can also be achieved through attention to the quantity, timing and method of application of nutrients to forage crops and utilising advances made through genetic improvements.

scholarly journals CH4 and N2O Emissions From Cattle Excreta: A Review of Main Drivers and Mitigation Strategies in Grazing Systems

2021 ◽  
Vol 5 ◽  
Author(s):  
Julián Esteban Rivera ◽  
Julian Chará
Keyword(s):  
Food Production ◽  
Carbon Capture ◽  
Production Systems ◽  
Animal Manure ◽  
Mitigation Strategies ◽  
N2o Emissions ◽  
Enteric Methane ◽  
Grazing Systems ◽  
Reduce Emissions ◽  
Ch4 And N2o

Cattle production systems are an important source of greenhouse gases (GHG) emitted to the atmosphere. Animal manure and managed soils are the most important sources of emissions from livestock after enteric methane. It is estimated that the N2O and CH4 produced in grasslands and manure management systems can contribute up to 25% of the emissions generated at the farm level, and therefore it is important to identify strategies to reduce the fluxes of these gases, especially in grazing systems where mitigation strategies have received less attention. This review describes the main factors that affect the emission of GHG from manure in bovine systems and the main strategies for their mitigation with emphasis on grazing production systems. The emissions of N2O and CH4 are highly variable and depend on multiple factors, which makes it difficult to use strategies that mitigate both gases simultaneously. We found that strategies such as the optimization of the diet, the implementation of silvopastoral systems and other practices with the capacity to improve soil quality and cover, and the use of nitrogen fixing plants are among the practices with more potential to reduce emissions from manure and at the same time contribute to increase carbon capture and improve food production. These strategies can be implemented to reduce the emissions of both gases and, depending on the method used and the production system, the reductions can reach up to 50% of CH4 or N2O emissions from manure according to different studies. However, many research gaps should be addressed in order to obtain such reductions at a larger scale.

Effects of oral nitroethane administration on enteric methane emissions and ruminal fermentation in cattle

2011 ◽  
Vol 166-167 ◽  
pp. 275-281 ◽  
Author(s):  
Erin G. Brown ◽  
Robin C. Anderson ◽  
Gordon E. Carstens ◽  
Hector Gutierrez-Bañuelos ◽  
Jackson L. McReynolds ◽  
...  
Keyword(s):  
Methane Emissions ◽  
Ruminal Fermentation ◽  
Enteric Methane ◽  
Enteric Methane Emissions

scholarly journals Comparison of enteric methane yield and diversity of ruminal methanogens in cattle and buffaloes fed on the same diet

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256048
Author(s):  
P. K. Malik ◽  
S. Trivedi ◽  
A. Mohapatra ◽  
A. P. Kolte ◽  
V. Sejian ◽  
...  
Keyword(s):  
Host Species ◽  
Methane Emissions ◽  
Species Level ◽  
Mitigation Strategies ◽  
Methane Yield ◽  
Pennisetum Purpureum ◽  
Enteric Methane ◽  
Archaea Community ◽  
Enteric Methane Emissions

An in vivo study was conducted to compare the enteric methane emissions and diversity of ruminal methanogens in cattle and buffaloes kept in the same environment and fed on the same diet. Six cattle and six buffaloes were fed on a similar diet comprising Napier (Pennisetum purpureum) green grass and concentrate in 70:30. After 90 days of feeding, the daily enteric methane emissions were quantified by using the SF6 technique and ruminal fluid samples from animals were collected for the diversity analysis. The daily enteric methane emissions were significantly greater in cattle as compared to buffaloes; however, methane yields were not different between the two species. Methanogens were ranked at different taxonomic levels against the Rumen and Intestinal Methanogen-Database. The archaeal communities in both host species were dominated by the phylum Euryarchaeota; however, Crenarchaeota represented <1% of the total archaea. Methanogens affiliated with Methanobacteriales were most prominent and their proportion did not differ between the two hosts. Methanomicrobiales and Methanomassillicoccales constituted the second largest group of methanogens in cattle and buffaloes, respectively. Methanocellales (Methanocella arvoryza) were exclusively detected in the buffaloes. At the species level, Methanobrevibacter gottschalkii had the highest abundance (55–57%) in both the host species. The relative abundance of Methanobrevibacter wolinii between the two hosts differed significantly. Methanosarcinales, the acetoclastic methanogens were significantly greater in cattle than the buffaloes. It is concluded that the ruminal methane yield in cattle and buffaloes fed on the same diet did not differ. With the diet used in this study, there was a limited influence (<3.5%) of the host on the structure of the ruminal archaea community at the species level. Therefore, the methane mitigation strategies developed in either of the hosts should be effective in the other. Further studies are warranted to reveal the conjunctive effect of diet and geographical locations with the host on ruminal archaea community composition.

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