I received an interesting e-mail (and follow-up with more details) from Tim S. It seemed like the sort of topic others would find interesting, and Tim seemed to be hoping for a pretty in-depth response…
…so I decided it would be a good opp to create a mini-podcast of sorts.
Here is his original question:
I have a question about sheet composting with shredded leaves in a field. Are there any reasons that a 12-18 inch layer spread over 2 acres wouldn’t produce a good casting after screening it? What are the drawbacks to a low maintenance system like this? Is it really necessary to keep adding food? Thanks!
Along with some additional info (and a bunch of questions) he sent in another email…
The location is a vacant 2 acre secluded field on the edge of town. I have enough wet compacted leaves to spread a 2 ft layer on the whole area. I also have access to a big tub grinder and a bobcat loader. Currently there are numerous native soil worms and red wigglers on the edge of the pile. I figured with a minimal investment in some Euro’s, along with the natives, I could populate the 2 acres.
I was wondering if there was any reason why I shouldn’t shred the leaves, spread them out, and leave them until the material was processed enough to contain a majority of castings? Is there any reason you HAVE to use windrows, or feed them regularly?
I’m intending on having a commercial product (castings and bait worms) so the material must be in a decent condition to screen out the worms and castings. So are leaves alone enough to make this work?
Is it neccessary to pre-compost them? What are the drawbacks compared to a standard windrow and regular feeding system?
If it won’t work, would mixing the leaves with grass, food scraps, etc before spreading work?
Would compaction be a problem for finely shredded leaves? Would added wood chips help with that?
Here is my response:
– Very promising opportunity…BUT, would be incredibly challenging to make it work as a highly-effective worm castings AND bait farming operation.
– Nice piece of land in a good location.
– Great supply of starter materials
– Helpful equipment
– Starter population of Red Wigglers
1) Lack of Control – Tim is in a decent location for outdoor worm farming, but still too many variables outside of his control (especially true for a serious castings operation).
2) Castings/Bait Combo – Can be challenging to create system highly effective for BOTH castings and vermiculture, especially with so little control over environmental factors.
3) Logistical Headaches – Without separation of worm zones and (worm farmer) working zones, how do you harvest without damaging the bed?
4) Not Enough Nutrition – Leaves alone won’t provide enough nutrition for top notch castings, let along castings AND fat bait worms.
– Based on the resources available and location, seems like a great opportunity for some sort of “eco-farming” operation.
– Vermicomposting trenches or windrows with crop beds running along both sides.
– Fantastic potential for demonstration project and profit from selling top notch, naturally-grown produce.
See “SPIN Farming”
– During spring and fall, likely lots of composting worms that could be harvested a sold as well
– Boost the nutrition in the beds with aged manure and – even more beneficial from an education standpoint – urban organic wastes (food scraps, coffee grounds, grass clippings).
– DO make sure to do everything “by the book” (permits etc), especially if working with manures (and of course when involving the public in any way)
UPDATE: Tim wrote in with some additional questions and I added a post with my (written) response to those as well. You can find it here:
The Two Acre Worm Farm – Update