Reducing losses of soil carbon
Carbon in soils can be lost through oxidation a lot easier than it can be gained. There will be certain losses from parts of any system, but minimising these losses should be every farmer or growers aim. There are several mechanisms that encourage oxidation of carbon:
Cultivations
When soils are cultivated, carbon can be oxidised very rapidly. The extra air introduced in to the ecosystem aids oxidation and reduces microbial life in the soil that helps to turn organic matter in to more stable humus. These effects can be reduced by:
- Cultivating at shallower depths
- Reducing the frequency of cultivations
- Making sure the soil conditions are good - i.e. not frozen, too wet or too dry
Livestock
In livestock systems, where there is often very little cultivation, management practices can still play a significant role in managing soil carbon levels. The key principle is to minimise damage to soils, which can be achieved by:
- Minimising poaching
- Ensuring stocking densities are correct
- Think about movement of machinery, people and animals when feeding
Soil management
As well as the specific items already mentioned, a more general carbon-focussed approach to soil management is valuable to ensure carbon losses are minimised:
- Minimise compaction
- Improve soil structure
- Peat soils are a special case, where soil carbon losses can be huge - as they are almost pure carbon, any excessive cultivation is going to create excess carbon losses