3 The composting process As described in the section on organic matter in soil processes, the composting process happens due to the activity of micro-organisms (bacteria) and other larger organisms like worms and insects. These need certain conditions to live. | 3 The composting process As described in the section on organic matter in soil processes the composting process happens due to the activity of micro-organisms bacteria and other larger organisms like worms and insects. These need certain conditions to live. These include moisture and air. To make the best possible compost the micro-organisms must be able to work optimally. This can be achieved if the following four factors are combined to the best advantage type of organic material air moisture temperature The acidity pH is also considered by some to be an important factor. Acidity depends on the air and moisture flow. A compost heap that is properly composed will seldom get too acid. The composting process will be optimal when various materials of different decomposition rates are combined the different materials are well mixed the size of the heap varies from 1 x 1 meters to 3 x 3 meters. This makes it possible for the temperature to stay constant within the heap. A good composting process passes through 3 consecutive stages these are as follows a heating phase fermentation a cooling down phase a maturation phase It is not easy to draw the line between these stages. The process takes place very gradually and with the help of continuously changing micro-organisms the organic material is converted into compost. The composting process 11 Heating phase During the first stage of composting the compost heap starts to heat up considerably. This effect is known as fermentation and is the result of the breaking down of the complex and tough fibrous material of the organic matter. This fermentation process decomposition is strongest in the centre of the heap. To get the fermentation going quickly and effectively a number of factors are important. In the first place the compost heap should be made of all sorts of organic materials. Secondly the right microorganisms have to be present. Thirdly it is very important that there is adequate oxygen and water. If these three .