When aerating compost, it is important to ensure a sufficient supply of air to meet the oxygen requirements of the microorganisms and to promote the decomposition of ammonia and methane. There are two basic ways in which air can enter the compost:

• Self-aeration
  Here, the air is utilised by the microorganisms and insects in the compost material to support the composting process . The air supply is therefore passive.
• Forced aeration
  Air is actively blown into the compost material to improve the oxygen supply and accelerate the composting process. This can be done by using ventilation shafts or by mechanical aeration.

The advantages of forced aeration are that it enables a better and controllable air supply and can therefore accelerate and stabilise the composting process. The disadvantage, however, is that it requires additional infrastructure and energy for aeration.

With self-aeration, on the other hand, no additional energy is required to introduce air into the compost material. As the air is supplied by the microorganisms and insects in the compost material, no additional infrastructure or equipment is required. However, as it is a natural process, it becomes more difficult to control the air supply and ensure that a sufficient amount of oxygen is present. Therefore, the composting process can be incomplete, which can lead to insufficient decomposition of organic waste, resulting in a non-homogeneous end product.