Vermicomposting: Technical Options

Bed System

The bed system holds the disadvantage that each bed takes up a considerable area of ground in relation to the relatively small amount of waste processed.

In fact, a single layer bed vermicomposting system would take up to six times the land area when compared with windrow composting and, because of this, stacking systems are being used. In stacked systems, containers filled with waste and earthworms are stacked on top of each other to make efficient use of space.

In some stacking system these are optimised to help separate out earthworms according to age by using containers with mesh bases, which are periodically stacked one on top of each other allowing earthworms to migrate upwards into the new containers filled with fresh waste. After several months, mature earthworms are harvested in high densities from the top container while young earthworms and cocoons can be found at lower levels.

'Automated Reactor' Systems

'Automated reactor' systems allow waste to be fed from a gantry above the reactors while finished vermicompost is collected from the base using breaker bars. The idea behind this system is that the earthworms will always move upwards into the thin layers of fresh waste leaving behind vermicompost, which is then automatically removed from the reactor by an agitated scraper bar continuously running along the bottom mesh.

In India, although smaller-scale reactor systems are now being marketed, most vermicomposting systems would appear to be based on either outdoor windrows or shallow covered beds.

Beds are usually made from wood or railway sleepers with a water-permeable liner membrane to contain the earthworms and waste.

 The beds are shallow to minimise compaction (usually no more than about half a metre high).

While ensuring aerobic conditions is essential, great care must always be taken to seal the top surface of the beds in order to prevent earthworms from escaping.

Conclusion
Simple outdoor bed systems are relatively cheap to make and can occupy areas of many hundreds of square metres. However, the large outdoor areas required need constant attention and feeding, and also attract pests which can can pose extensive management problems.

Vermicomposting systems can also be used for processing waste types, such as sewage treatment works and food waste sludge cake .

Starter kits are readily available for setting up vermicomposting/vermiculture systems.

Starting new vermicomposting sites will usually involve an initial intensive earthworm breeding phase, carried out initially indoors in boxes or trays, combined with outdoor beds for the larger worms when they get older, where earthworms are grown to maturity producing vermicompost during the process.

 

 

source:http://www.compost-india.com/html/vermicomposting__technical_opt.html