Wednesday, September 7, 2016

Microbes in your soil

In this blog post Letetia Ware explains how to make bokashi, and also a simple fermented liquid, a simple fungi-rich compost and potting soil.  It documents information provided by her during the Food Garden Group's 2016 winter workshop.


Bokashi is a Japanese term for 'fermented organic matter'. It is often referred to as a type of composting, but it is actually 'a facultative anaerobic fermentation process' (a fermentation process that does not use air), resulting in a much different product than that produced via composting. People like bokashi because it is very easy, generally free of bad odours and incredibly beneficial to soils.

To make bokashi you need:
  1. A bucket with a tap at the bottom so you can drain away excess fluid
  2. Bokashi mix, ie. wheat or rice bran inoculated with a special mixture of microbes. Maze is a good brand.
  3. A trowel or potato masher to push down the vegetable mix
  4. Food waste. This can include meat and dairy.

Bokashi kits containing a bucket with tap, trowel and bokashi mix can be purchased at hardware stores.
bokashi bucket, trowel and bokashi mix in the cupboard under our sink
Making bokashi is easy:
  1. Add kitchen vegetable waste to the Bokashi bucket regularly, for instance once a day.
  2. Push it down to take the oxygen out
  3. Sprinkle with bokashi mix
  4. Keep the bucket in warmish conditions
You can take liquid out of the bucket via the tap at the base.

bokashi liquid drained from a full bokashi bucket
If you tap liquid from a full bokashi bucket, you may get around half a litre of liquid.  Dilute this liquid 1:10 and then spray on plants or soil in your garden.

You can bury the content of the bucket directly in the food garden where it will become a beautiful chocolate crumb in about 30-40 warm days, or you can add the full bucket to the compost heap. Don’t add it as one solid mass, but spread it out in the heap. The waste will now become compost. When you use the compost in your vegie garden, the microbes will be added to your soil.

In the Tasmanian climate bokashi is the simplest method of adding beneficial nutrients, enzymes, antibiotics, growth promotants and beneficial fermenting organisms to your soil.

Whilst the micro-organisms will be most active in late Spring through to early Autumn, the metabolites (digested juices) they produce will be beneficial all year round.

A simple fermented liquid

In this recipe we make a liquid that ferments and that can then be used to add micro-organisms and metabolites (beneficial nutrients, enzymes, antibiotics, growth promotants) to your compost and soil.

In an empty 3-litre milk bottle:
  1. Put 1 cup of bokashi
  2. Add 1 cup of milk
  3. Add 3 tablespoons of molasses dissolved in 1 cup of luke-warm water.
  4. Fill up the bottle with cold water (rain water or bottled water preferable over chlorinated tap water.

Letetia demonstrates putting together the ingredients for the fermented liquid
Put the cap on the bottle and shake it slowly until everything is well-mixed.
Keep the bottle in a greenhouse or a nice warm area indoors for 14 – 28 days.
Keep the bottle closed.

The photo above shows a bottle in which fermentation is in progress.  Curd is collecting at the top of the bottle, and bokashi hulls (the hulls from the wheat or rice bran) are collecting in the bottom.

The mix will continue to ferment until it is no longer cloudy and you are left with floating curd at the top and sunken hulls at the bottom.  This will be after 14 – 28 days.  If, at that stage, particles remain in the top of the bottle, filter the liquid.

The liquid remains viable for 12 months and can now be kept in cool conditions.

On a day when the temperature is going to be 15 degrees or more:
  1. Add 100 – 150 ml of the liquid to 10 litres of water (a watering can)
  2. Add PowerFeed (30 ml.) and Seasol (20 ml.) and mix well
  3. You can also add liquid from a bokashi bucket
  4. Make sure the soil is moist before spraying so organisms can start working straight away
  5. Spray early in the morning, initially once a week, then once a fortnight.
  6. Disperse the mix over 10 – 15 sq. metres of garden
Instead of a watering can, you can use a low-pressure sprayer, but don’t use a pressure sprayer with pressure over 100 psi, as the microbes in the liquid may not survive the pressure.

A simple fungi-rich compost

Most soils have more than enough bacteria in them, but need more fungi, protozoa and nematodes (that eat fungi and bacteria).

By adding this compost to your soil, you will add the full range of beneficial micro-organisms that will continue to convert nutrients to directly feed the plant and provide disease and pest suppression both in the soil and for your plants.

To make this compost:
  1. Find a shady level area of around a metre in diameter in a spot that is not sheltered from rain (not on concrete).
  2. Remove all weeds, but leave the top-soil and dig the area to make it nice and friable and draining.
  3. Now on the bare soil put a mix of things you happen to have at the time, for instance, the content of a bokashi bucket (no need for it to be digested), solids from the bottom of a bottle of fermented liquid, bokashi grains, PowerFeed and kelp.
  4. Now completely cover what is on the ground with a straw pile consisting of wheat straw, rye straw or organic sugar cane mulch. Sugar cane mulch is ideal because it breaks down slowly. It is best to use an organically certified straw.
  5. Repeatedly add a layer, then spray it with diluted fermented liquid (see above)
  6. Add to the pile until it is around a metre high.
  7. Make sure the pile remains moist at all times (not wet): over the following days and weeks and months water the pile from time to time with a 10-litre watering can of fermented liquid plus PowerFeed or Seasol as described above.

This will be a perfectly aerobic environment in which micro-organisms will digest the straw or mulch and spread in the pile in a perfect balance. It is a perfect reproductive environment. The straw will promote the fungi. The pile will shrink a lot and be completely broken down in 12 months.

To make this compost do not:
  • Do not use a compost bin for it does not allow enough air to circulate.
  • Do not use pea, oats or barley straw because they are soft straws that hold too much water and become slimy.
  • Do not cover the heap because the process needs to be aerobic (= using air)
  • Do not do any of the traditional things you do with compost heaps, ie. do not add manure or lime or turn the heap.
  • Do not use a compressed bale without ‘fluffing it up’.

In the end you have a nice soft soil with lots of fungi, with a pH of between 5 and 6.

You can put this compost straight on your vegie bed.

This compost was made without having to do all the traditional things you do when making compost, and without using anything that contains seeds or chemicals or pathogens or diseases, as many manures do.

A homemade potting soil

In this potting soil we use:
  • Munash rock dust (for sale at Mitre-10 and Bunnings). This is special rock dust with great balance of minerals that is based on the perfect soil mineral ratio..
  • HALS biochar. It is much better than just charcoal from a wood heater (too alkaline).
  • Richgro certified organic mushroom compost (used in this recipe for humus)
  • Neutrog Seamungus composted seaweed + fish + humuc acid + fish. Seamungus can be used on its own around fruit trees at the rate of 1 cup/sq.metre every 4 weeks

First we make the two ingredients of the mix: fertiliser and potting mix.

  1. Fertiliser = 1 part of Munash + 1 part of HALS biochar + 1 part of Richgro + 1 part of Seamungus
  2. Potting mix = 4 parts screened compost (not from pine bark ; put through a sieve to filter out large bits ; compost can be HALS compost) + 1 part washed course bedding sand + 1/10 part vermiculite
Now we put the two together in our potting soil: 5 parts Potting mix + 1 part Fertiliser

You can also use the Fertiliser on its own for vegie beds and under fruit trees (1 cup/sq.metre every 4 weeks).

Many thanks, Letetia, for all this valuable information, and for checking the accuracy of this blog post before it went online. We had a great workshop and learnt a lot.

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