Decomposition of Carbohydrates

In the carbon cycle carbohydrates are produced by plants by utilising Carbon Dioxide (CO2) and decomposed by animals as CO2 and by bacteria as CO2 and Methane (CH4). | Technology Options

Decomposition by bacteria takes mainly place in anaerobic environments resulting in relatively more CH4 and little CO2. Such an environment is present in the rumen and colon of ruminants respectively equines, domesticated as well as wild life species.

If the biomass is not consumed but left in the field to decompose then CH4 is still produced by bacteria in the soil and in insects responsible for this decomposition. The overall reduction in CH4 emission through natural decomposition instead of digestion through ruminants and equines will therefore be limited.

If the biomass is consumed by mono-gastrics then the decomposition of structural carbohydrates (fibres) takes mainly place in the manure. For differences between species see species.

When manure is stored under humid warm anaerobic conditions then again increased CH4 will be produced. CH4 from manure can more easily be captured than CH4 released by animals. When it is used as fuel it will be converted in CO2 that contributes many times less to global warming than CH4. For more see: Methane as a contribution to greenhouse gas emissions

The lowest production of CH4 can be realised through burning. Nearly all carbohydrates are converted back into CO2. A decrease in burning for whatever reason can so result in an increase in CH4 emission being it through conversion by animals or through natural decomposition.

The debate on the contribution of livestock to global warming through CH4 emission is still ongoing. The CH4 from manure can be captured and reduced to CO2 through burning. This is more an opportunity for industrial systems and in mixed systems where manure is stored than for either grazing or small scale mixed systems. Whether feeding or other measures may help to reduce overall CH4 emission is still subject of discussion.

[Livestock & Environment Toolbox Home]