Hi Stacy,
We model a couple different styles in Southern Mindanao. We have demo-ed bamboo box structures resting on the ground, small raised wooden boxes with a welded wire and net screen system, and extensive cement block systems under our goat houses.
The primacy of bamboo as an appropriate method makes village demonstration valuable, and approachable. These are filled once and then harvested on a set schedule. These produce vermicompost, but we loose nutrition during rain, worms can migrate, and rebuilding boxes takes away from other work events. Moving where vermicompost is created with on-ground bamboo boxes perhaps/likely would benefit an orchard over time.
However, for our production purposes, as vermi-compost is our farm fertilizer and part of some program supplies, our block systems are the most viable. These are raised, with a welded wire and screen layer, then filled with goat manure, chopped banana stalk, worm stock, and occasional stick/leaf/peelings. We do fill a series of boxes primarily with water hyacinth, as that is a current plant in our fish ponds we remove intermittently.
To harvest vermicompost, we remove and reserve the worm stock, and sift the product much like sand is sifted for making cement. The fine finished product is stored in a covered barn, and what lumpy material remains is returned to another vermi-box along with the removed worm stock. We have three boxes, 1 meter by 20 meters long each. These are harvested on a rotating basis to maintain constant production.These boxes form a downhill border under our goat barns. The block structure of these boxes doesn’t rot, so is advantageous to our staff from a work perspective. What we teach in community village extension is bamboo, rice sack, or banana trunk sides with a sack bottom layer. The demo of block boxes helps expand thinking if a village chairman or religious leader wanted to catalyze a village level project.
The elevated screen layer does allow some finished product to fall, but we do not actively harvest this in a continual basis the way some continued input/harvest systems work. This could be augmented with a shaking or prodding mechanism.
We do capture leached liquid with a buried drum in the runoff channel, but this does not compromise a significant resource on our farm. We have used it as a foliar fertilizer in the past, but the impact was not observable enough for our staff to continue. Us revisiting this and conducting a trial with control over a year would be beneficial.
We loosely cover the worm boxes with a raised roof, and manually water depending on current weather conditions. We do not deal with overwhelming ant interference.
We remove any grubs during the worm stock removal.
We find a lot of value in our vermiboxes. It is our sole fertility source outside of mulch/cover cropping, and turns waste product of banana stalk and goat manure into a valuable resource. The finished product is “clean” culturally, so has more value than both banana stalk and goat manure individually. These resources on their own have lowered frequency of usage. Our worms have added value in other ways; starter stock for other farmers/programs we run, additional feed for our chickens, and fish bait if needed pre-harvest. Our current boxes have been in constant production for 10 years, and is seen as a community resource. What we do sell, currently, is often for nursery purposes, either for their own seedling production or larger commercial scale.
