Insect life cycles - Phase I
- Traditionally,
during Phase I, raw ingredients are mixed, wetted and formed
outdoors into large stacks,
which are mechanically turned in an attempt to maintain aerobic conditions.
- Temperature
differentials arise between the centre (70-80oC) and edges (ambient) of the stacks. At this time, unwanted
organisms such as flies, mites, nematodes can readily develop in these outer compost layers.
- Towards the end of Phase I, compost is formed into "windrows"
in covered but open-sided compost sheds, and regularly turned through a 7-8 day period.
- Primarily
to reduce emissions (odour and ammonia) and minimise anaerobic cores, under-stack aeration was introduced
(Von Minnigerode, 1981) to improve Phase I process control.
- Phase I can be shortened and more effectively controlled
in positively aerated
chambers.
- The process, known as in-vessel or bunker composting, is achieved by pumping
air into the compost through air spigots, with duration dependent on oxygen demand of the microbial
population. This system has been further refined and modified to develop total indoor systems
