Just like fish farming, you need to cull fish to grow fish, the same with worms, with a big extra. The secret to worm farming is simple you have to extract worm all the time, but unlike fish farming you also have to remove the cast at the same rate. With fish farming you leave their water behind. Without doubt you are leaving cast behind as well as not harvesting, when you harvest they rapidly replicate themselves. When you leave cast behind the mechanism for cocoon burst and egg creation is switched off. Think of a bell curve, on the left hand side is worm multiplication in fresh food, then as cast appears the bell curve peaks, from there on it goes down hill in direct proportion to the quantity of cast remaining. It is always the same mistake. So harvest on the left hand of the curve and replication will be doubling every thirty days, then strip stock at the peak when cast appears, reset the pits and the growth rate remains near vertical. In the bell curve, the 20kg figure relates to the introduction of "start up" worm stock to get on the vertical part of the curve from the beginning in a pit that is 4.5 square metres in size. You can scale up or down from this area to calculate the start up stock and the growth factor. This assumes that pit management is constant and correct. The right hand side of the bell curve means that when the worms have converted the material fully to cast then there will be no worm stock left, but 100% cast.
We have a weekly harvest all the time by drawing worms to a special formula they love over all other materials, we use simple experience about how many kilos to remove. Do not over harvest as you slip to far down the left hand side of by now a flat section in the bell curve, likewise keeping too much allows you to plateau. Everyone who has ever grown worms ends up always some where down the right hand side. It took me a long time to figure out what was really going on. When the worm stock has been harvested at the 60 kg reference point, you can take the cast out, at this time we call it vermi-compost not vermi-cast and we feed it to a pit where "sacrificial" worm easily converts it to vermi-cast so as you also end up with the best possible cast. The trick here is to keep feeding vermi-compost to the "sacrificial" worm so as not to sacrifice them! A vertical pit is best for this so you in fact top feed it and the worms continue to move up and do the conversion to cast. In the meantime you have extracted peak worm and reset the first pit to 20 kilos only for peak regrowth.
Offered by Darryl.