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Soil Factory Using Bokashi Ferment

I am seeing the term soil factory used more often, usually in discussions about Bokashi or Vermicomposting. I’ll restrict this blog to discussions about Bokashi, but most of the comments also apply to Vermicomposting.

It is claimed that Bokashi ferment, the material remaining after the fermentation process, can be used to make soil, which can then be used for house plants or in the garden. This would be quite a feat if true. It takes nature millions of years to make soil and now Bokashi enthusiasts can do it in a couple of weeks.

Bokashi Soil Factory, by GardenMyths.com

Bokashi Soil Factory, by GardenMyths.com

Soil Factory Using Bokashi

How does the soil factory work? The following description from the Bokashi Composting Guide is a good explanation of the process.

“Making Your Own Potting Soil: To create your own soil factory you will need a large open container or tub. First add a layer of used soil (20 litres), then dump in the contents of your Bokashi bucket and break apart the waste. Next add another 20 litres of soil and mix it into the fermented waste. Finally top off with another 20 litres of soil and ensure that all the contents are moist but not wet. After a few weeks you will have a good supply of an amazing nutrient rich potting soil.” (ref 1)

I wonder how much soil you produce? I’d guess it is just 60 liters, the amount of soil you started with. A pail of Bokashi ferment is mostly water. A small amount of organic matter would be added to the soil but would have almost no effect on the volume of soil.

Soil consists of dead organic matter, sand, silt and clay. A soil factory does not produce any sand, silt or clay so it does not produce soil. The term soil factory is very misleading.

Statements like “A soil factory is a place where you produce high quality nutrient rich soil”, are just plain wrong. It does not produce soil, and there is no evidence that the resulting product is ‘high quality’ or ‘nutrient rich’. The soil structure has not changed. The only thing that has happened is that it has a higher level of organic material, but this organic material has not started to decompose as explained in Bokashi vs Composting.

Benefits of a Soil Factory

The term Soil Factory may be a poor selection, but there are some real benefits to it. I first became aware of the procedure of adding Bokashi ferment to soil through social media; it seems to be a more common practice in Scandinavian countries. In a few weeks the fermented kitchen scraps plus soil are turned into something that looks like soil. You no longer see the pickled scraps.

I gave the method a try and sure enough the fermented material falls apart fairly quickly and seems to dissolve in the soil.

The benefit for the home owner is that they don’t need a garden to get rid of their Bokashi ferment. They can do it right in their home and the resulting soil can then be used for house plants or planting containers. This certainly makes Bokashi more appealing for people living in apartments.

What Does the Soil Factory Produce?

The stories I heard from Finland and Sweden claimed that the Bokashi ferment decomposed in a couple of weeks after being added to soil. I haven’t found a single study that looks at what happens to the ferment once it is added to soil. To our eyes it seems to disintegrate into the soil, but decomposition is a chemical process and we humans can’t see it happening.

We do know that decomposition is a slow process that happens in the presence of both bacteria and fungi. Knowing this, it is almost a certainty that the soil produced by the soil factory does not contain decomposed material. It might look like finished compost, but it’s not.

Traditional bin composting takes months, and even so-called finished compost still takes years to complete the decomposition process.

The result of the soil factory consists of the added soil plus un-decomposed organic matter. There is nothing wrong with that. The real value of organic matter is that it decomposes slowly over time – that is a good thing.

A New Type of Soil Factory

While experimenting with this process I decided to try an improved soil factory method. The current method requires that the soil and Bokashi ferment sit for a couple of weeks. My new method eliminates this two week waiting period, making it much faster.

The Instant Soil Factory

Take your Bokashi ferment and homogenize it in a blender to make a smoothy out of it. Then pour it into the soil. Mix it up and you are done. Instant fortified soil with no waiting period.

The ferment homogenizes very easily in the blender since the food scraps are already mushy and contain a lot of water.

You can also replace the soil with coir and produce a product free of insects and plant diseases. The coir is quite dry and easily absorbs all of the liquid in the ferment. The result is a fairly dry, soil-less mix that has no odor. The ferment will continue to decompose over time and help feed plants.

I call this new method the Instant Soil Factory.

References:

  1. Bokashi Composting Guide; http://www.greencalgary.org/index.php/download_file/view/493/343/
  2. What is Bin Composting?; http://www.gardenmyths.com/compost-what-is-compost/

 

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Robert Pavlis
Editor of GardenMyths.com
I live in southern Ontario, Canada, zone 5 and have been gardening a long time. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

I hope you find Garden Myths an educational site that helps you understand your garden better.

7 Responses to 'Soil Factory Using Bokashi Ferment'

  1. Using a blender seems like more work, not less? If the fermented food breaks down in about two weeks anyway, I’d rather just wait, instead of batchblending 2 liters at a time.

    • I was not suggesting that blending is a better option. The point is that just because you can’t see the pieces of food – does not mean it is decomposed. So it does not “breaks down in about two weeks”. Only the visible large pieces become smaller pieces.

  2. Roland says:

    Dear Robert
    I like your practical advise. I have been thinking about how you can speed up the process even more. Why not put the compost into the blender and add it straight to the garden. This way the bacteria and funghi in the garden can process the faster. It will be a sort of irganic digestion and it could could be called it „In Plot Composting“

    • Not sure how you are defining compost, but using the normal definition, you don’t need to blend it – just spread it in the garden.

      • Roland says:

        Sorry, my English was not precise enough. I am Swiss. So in the (Swiss) German language compost is also the stuff you put on your compost heap.
        So what I actually meant was to put the food left overs into a blender and then directly scatter it onto the soil in the garden. This way you can save two weeks of bokashi fermentation.
        After having read your article about bokashi fermentation I have come to the conclusion that this does probably more harm than good. If I understand correctly, it is important that for Bokashi fermentation no oxygen most be present. So this means anaerobic digestion.
        (https://en.m.wikipedia.org/wiki/Anaerobic_digestion)
        This is the process used in biogas plants to produce biogas. This process produces rather large amounts of methane and CO2. In a biogas plant the methane is captured and used to produce electricity or it may be even purified and fed into the gas grid.
        However with Bokashi fermentation the methane will be vented into the atmosphere. The International Panel on Climate Change says that Methane is 86 times more potent greenhouse gas carbon dioxide.
        (https://www.scientificamerican.com/article/how-bad-of-a-greenhouse-gas-is-methane/)
        Much lower amounts of methane are produced during normal composting as this is an aerated process. So I think it is very likely that normal composting is much more climate friendly than Bokashi, and Bokashi is even harmful.
        It is probably more environmentally friendly to dispose food leftovers via garbage disposal unit into the sewage system than doing bokashi.
        The sewage treatment plant captures the methane, bokashi cannot do this.

        • Your comment “put the food left overs into a blender and then directly scatter it onto the soil in the garden” is very interesting. In fact, when I did the blending work on bokashi, I came to the same conclusion, and tried just blending kitchen scraps – no composting and no bokashi. It worked just fine, and will be a topic for a future post.

          Your comment about methane is correct. It is very harmful to the environment, and bokashi will produce more than composting. Bokashi is used mostly in very small quantities, at least as described in my posts. The amount of methane produced is small compared to all of the other problems we have with global warming. It also loses less nitrogen compared to compost. Does that offset the methane produced?

          You may be right – putting it in the garbage may be better environmentally.

  3. Mrudula says:

    Yes. I have tried this soil factory method for Bokashi ferment. It turns into a soil like structure or more like a ready compost in 2-3 weeks with a nice earthy smell. But I have a problem while mixing this Bokashi ferment with soil and coir. It gives out real foul smell. So this time I have put this ferment and soil in layers and not mixing it to reduce the smell. I will find out in a couple of weeks whether this gives the same result or not.

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