Nav: Home

New method for quantifying methane emissions from manure management

August 17, 2016

It is currently not possible to quantify emissions of methane from livestock manure. This is a significant problem, in particular at a time where the EU Commision requires Denmark to reduce drastically emissions of greenhouse gases from agriculture. Without methods to quantify emissions, it is also not possible to document effects of changes in management.

A new research article, published this week in the journal PLOS ONE, addresses this challenge and proposes a method which could be an important step towards quantifying methane emissions and degradation processes associated with manure management.

The specific challenge is that the mainly liquid manure (slurry) is collected in pits under animal confinements for up to a month before exported to an outside storage tank, or for treatment. During this period degradation of manure organic matter begins and may lead to emissions of both methane and carbon dioxide. However, animals in the house are also a source of both gases, and in practice emissions from livestock and their manure cannot be separated. As a result, the total emission of methane from manure in pits and outside storage tanks, and the degradation of manure organic matter, cannot be verified.

The new method proposed here is based on laboratory measurements of methane production in liquid manure samples collected on farms. A simple model is used to calculate daily emissions. This model can then be used to evaluate effects of changes in management or treatment of the manure, for example biogas treatment.

Methane is, after carbon dioxide, the most important source of greenhouse gases from agriculture, and the most important on-farm source. Here the largest single source is animal digestion, especially in ruminants such as cattle, whereas on pig farms manure is the main source. Since the residence time of methane in the atmosphere is short compared to other greenhouse gases, a reduction of methane will be particularly effective in the short term at reducing climate forcing. Moreover, methods to reduce methane emissions from manure are already available (biogas treatment, slurry acidification). For these reasons methane emissions from livestock manure is an obviouos target for greenhouse gas mitigation.

Degradation of manure organic matter leads to emissions of methane, but even larger emissions of carbon dioxide. Both methane and carbon dioxide contain carbon from manure organic matter that is degraded. This loss of organic carbon is critical for the biogas potential of manure which is directly related to the degradable organic matter left in the manure. For example, a shorter collection period would likely increase biogas production while at the same time reducing methane emissions, but currently these effects cannot be documented. The article discusses this synergy and concludes that a new method must also be able to quantify the emission of carbon dioxide, in order to estimate the loss of degradable organic matter from slurry pits. Plans to further develop the method have been described in a new research proposal in collaboration with research institutions in Germany, Netherlands, Great Britain and Sweden, and a Swedish company.
-end-


Aarhus University

Related Methane Articles:

Microbial fuel cell converts methane to electricity
Transporting methane from gas wellheads to market provides multiple opportunities for this greenhouse gas to leak into the atmosphere.
Methane seeps in the Canadian high Arctic
Cretaceous climate warming led to a significant methane release from the seafloor, indicating potential for similar destabilization of gas hydrates under modern global warming.
Methane emissions from trees
A new study from the University of Delaware is one of the first in the world to show that tree trunks in upland forests actually emit methane rather than store it, representing a new, previously unaccounted source of this powerful greenhouse gas.
Oil production releases more methane than previously thought
Emissions of methane and ethane from oil production have been substantially higher than previously estimated, particularly before 2005.
Bursts of methane may have warmed early Mars
The presence of water on ancient Mars is a paradox.
New method for quantifying methane emissions from manure management
The EU Commision requires Denmark to reduce drastically emissions of greenhouse gases from agriculture.
New 3-D printed polymer can convert methane to methanol
Lawrence Livermore National Laboratory scientists have combined biology and 3-D printing to create the first reactor that can continuously produce methanol from methane at room temperature and pressure.
Arctic Ocean methane does not reach the atmosphere
250 methane flares release the climate gas methane from the seabed and into the Arctic Ocean.
Long-sought methane production mechanism identified
Researchers have identified the mechanism by which bacteria create methane, a potent greenhouse gas.
Retreat of the ice followed by millennia of methane release
Methane was seeping from the seafloor for thousands of years following the retreat of the Barents Sea ice sheet, shows a groundbreaking new study in Nature Communications.

Related Methane Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Moving Forward
When the life you've built slips out of your grasp, you're often told it's best to move on. But is that true? Instead of forgetting the past, TED speakers describe how we can move forward with it. Guests include writers Nora McInerny and Suleika Jaouad, and human rights advocate Lindy Lou Isonhood.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...