A study: "Effect of Substrate Depth on Vermicomposting"

[secondtry]

Hey all,

There has been a good bit of discussion about ideal depth for feedstocks in vermiculture bins, I have always been under the idea that 10-15 cm of feedstock is ideal, 30 cm is too deep IMO. This study below seems to agree, there are others out there in academia. This study also shows that the deeper the substrate (i.e., feedstock) the (exponentially) slower the time to process feedstocks to stability.

Singh N.B., Khare A.K., Bhargava D.S., Bhattacharya S. 2004.

Effect of Substrate Depth on Vermicomposting
Journal of the Institution of Engineers (India), Part EN, Environmental Engineering Division. Vol. 85, pp. 16-21. Sept. 2004
​

In view of the growing awareness about vermicomposting technology in recycling different types of organic wastes, the effect of substrate depth on vermicomposting was studied. The initial substrate depth of 5 cm, 7.5 cm and 10 cm remained aerobic while 12.5 cm and 15 cm thicknesses turned anaerobic during vermicomposting. The temperature in 12.5 cm and 15 cm sets rose up to 35 deg C in few hours which subsequently became lethal to earthworms. The initial substrate depth of 10 cm was found to be optimum organic loading for vermicomposting. The time for substrate stabilization during vermicomposting was also found to be lesser as compared to composting without earthworms. The substrate depth variation with respect to time followed an exponential curve.

HTH

 

[mad librettist]

does combining different species change this at all?

 

[secondtry]

This does not bode well for the 'flow-thru' vermiculture bins/socks on that DIY website...

 

[secondtry]

does combining different species change this at all?

I do not know but I don't see why it would. Vermiculture worms stay in the top of soils, around the top 30 cm AFAIK (but that's soil, not feedstocks), "night crawlers" and those types of worms go deeper AFAIK.

The problem too is the anaerobic nature of deep feedstocks/substrate in vermiculture bins.

All the best

 

[mad librettist]

This does not bode well for the 'flow-thru' vermiculture bins/socks on that DIY website...

bullshit. the entire wall of the worm bin bag allows the passage of air and moisture. They love it the whole way down. Measure from the outside wall directly into the bag and you don't get 20 cm away from an air source.

you got some blinders on methinks. I don't need any research to tell me this thing works. If you want to figure out why go ahead, otherwise how useful can this be? I'd love to know why my bin bag works so freaking well, much better than my 15 cm or so bins. I'd love to know why along with 2 bokashi buckets it can handle about 80% of the food waste of a meat eating couple with no time consuming harvesting by trapping or sorting worms... just grab it from the bottom and screen it if you want or just pick out any big tough bits.

The product at the bottom btw, 2nd, smells great, is fluffy, and shows no visible signs of anaerobic activity. There is no runoff.

 

[secondtry]

An important distinction is it seems this study was about feedstock depth, i.e., over 10 cm of un-processed feedstocks is not good, either as a one time application or if one adds feedstocks too often.

I will download the full text tomorrow. All the best

 

[secondtry]

bullshit. the entire wall of the worm bin bag allows the passage of air and moisture. They love it the whole way down.

The point here is that you are probably not adding too much feedstocks at one time or adding feedstocks too often. I was not referring to you. But if someone who doesn't have the experience you do uses that bin and loads it with say 15-20 cm of feedstocks they would not be doing themselves or their worms a favor.

And the core of the feestocks can be anaerobic even tho the outside is not.

you got some blinders on methinks. I don't need any research to tell me this thing works. If you want to figure out why go ahead, otherwise how useful can this be?

Very useful indeed. See my comments above about how your success is probally mostly do to your skill, not the bag.

I'd love to know why my bin bag works so freaking well, much better than my 15 cm or so bins.

See my previous comments and my post just above this one. If there is =<10 cm of new and/or in-process feedstocks over 30 cm of finished and stable vermicast there should be no problem. But if there is more than 10-15 cm of new and/or in-process feedstocks there could be problems in that the envrion could be less than ideal.

Vermiculture worms do not naturally live/work deep in soil, they stay in the top 20-30 cm AFAIK.

All the best

 

[mad librettist]

It really depends what you are doing. If you are trying to heat the bin you need to add a lot at once.

how much you feed is relative to worm population as well.

The directions for the bin bag don't state you should fill it up with food, any more than the directions for a regular bin.

but it seems to me I can fit more worms in here for the volume than I can in my plastic bins, which I have had longer. you think I first heated the bin bag on purpose?

anyway, I don't have just finished and unfinished in my bag. I have layers representing various stages in between. And sometimes yes a deep pocket of finished product so I get enough to use.

 

[secondtry]

Hey,

Yea I totally agree but I also believe (through reading various studies like the one above) that adding too much feedstocks is not wise, nor adding feedstocks too often and that less is more in terms of depth.

Why would you want to heat the bin? It's in your house right? I can't see a reason to heat bins if inside house.

All the best

 

[mad librettist]

heat - basement, but it's only half underground. Has a very poor outside door, and temps get below freezing on the coldest day. They hang out around 40.


I had noticed things slow down in the winter and the food waste piles up, and also that bokashi is very hot and will heat if you set it in a pile and cover it with bedding. So I had a kitchen powered little bio-heater, and the worms were very happy. If it got too hot they would make a ring around the center. production and waste disposal in the bin bag returned to fall or spring levels. The key was feeding all at once and packing it tight.

I know it sounds crazy but it worked.

 

[secondtry]

Mad.L wrote:

If you are trying to heat the bin you need to add a lot at once.

The key was feeding all at once and packing it tight.

This is where I disagree if you mean you add more than 10-12 cm or so of feedstocks at one time. If it's too cold put it in your bathroom or kitchen, it small enough.

Your happy with what your doing and that's all the really matters. This thread was not a "Mad.L's method sucks" thread, . This thread was for the vast majority of us who do not use your methods.

All the best

 

[mad librettist]

I'm adding more like 10 cm of feedstock, maybe less...

just with bokashi, it heats up.

and you brought up the bin bag, not me. so don't complain it's about mad l's method after you make it about mad l's method.

 

[secondtry]

Hey,

I didn't make it about your method, I simply mentioned a method people use which came to mind, I was also going to mention windrow vermicycling as a possible trouble area but I am unsure how deep those windrows are. I am looking into that right now and I hope MM can chime in here. Once I know how deep windrows commonly are I might add them like I did the bags.

I don't like you that much that I think of you all the time lol

 

[mad librettist]

well alrighty then.

 

[Can & Juana]

A test like that would have to be done using every possible type of container if you want to use the results in a broad way, like saying "more than 15cm is bad", or whatever.
Those results may be accurate with one specific bin type, using a specific amount of ventilation. Simply put, there is way too much variation among "bins" to make broad claims about anything.

 

[mad librettist]

precisely.

 

[secondtry]

Hey Can & Juana,

I don't agree, the container doesn't matter as much as the size, type, condition and depth of feedstocks. Ventilation isn't a concern as I don't think anyone here used forced air. Other lit I have read states the same, usually 10-15 cm is as deep as one would want to go with feedstocks. Naturally theses types of worms do not 'live' deep in soil AFAIK.

If anyone can show me why this study and other papers (which find the similar results) i have read are not applicable I would be happy to learn it.

Thanks

 

[Microbeman]

I add my food stock in less than 10 cm at a time, see that it is eaten then add another layer in my bins. In my barn, economics dictates 1.3 meters depth in a windrow but we leave the material for 9 months and there are 1000 kg minimum of worms in a volume 5 meters X 8 meters X 1.3 meters. I have found that lots of my bin worms seem to like the wet 'anaerobicish' [sic] depths of old bins. That is where I find my highest levels of naked amoebae.

edit' ideally windrows are about 45 cm deep considering the economics of windrows.

 

[secondtry]

Hey MM,

Thanks, great detail.

All the best

 

[mad librettist]

2nd, every link you gave applies, what's wrong is your assumption that there can be only one surface.

MM's account of feeding sounds pretty familiar to me...