Everything's Bamboo

The Funkytional Art of Appropriate Technology

Bokashi is a Japanese method of composting.

Traditionally it utilizes Effective Micro-organisms (EM’s) to assist in the process, but it can work with simple yeast. We have found since changing to EM’s the process is faster and sweeter smelling.

There are two methods of Bokashi, Aerobic(Oxygen) and Anaerobic (Oxygen free) In the Aerobic process the compost needs turned daily to mix the ingredients and keep the reaction temperatures down. Resting for a couple of weeks increases bio-available nitrogen by up to 25%. The Aerobic process is higher in the nitrate form of nitrogen which is better for grass and vegetable gardens.

It is important, in my opinion, to premix your compost with all the compostable ingredients AND EM’s and a starch for them to feed on. This could be flour, waste rice processing waste, Molasses, etc.Something to kick start the process. Also mixing in the Em’s, spreads them uniformly into the mix, no migration required. The whole pile goes off very rapidly and you have compost that is inoculated with the bacteria you WANT. Less smell, much faster process.

Anaerobic process takes about 8 weeks and decomposes at lower temperatures. The storage container has been lined with an insulation layer, and a large sheet of plastic. The storage area is filled with premixed dry materials and a mixture of molasses and EM are used to wet it. The filled unit is covered with the folded plastic and insulated with sacks of rice hulls.

This product is higher in NH4, nitrogen in Ammonia form. This is better for shrubs and trees. Since the process is cooler it is likely that less nitrogen and carbon will be burned off into the atmosphere. For Coffee, it can be made to be ready all at once at the times required.

Using the very same container, insulation, etc. The same mixed pile of materials can be Aerobically composted in less than two weeks using an air injection system. I am using a very large pond diaphragm pump. I also use it for compost teas. Ron Miller at Finca Santa Marta, an Organic farm here in Chiriqui, uses an inexpensive air blower that is less expensive and produces several times more air for his compost teas. These blowers can be connected to regular garden hose with a series of drip irrigation tees and each tee connected to a piece of cheap 1/2″ PVC electrical conduit. This conduit has 1/4″ holes drilled every 12- 18″, more or less. In a 4 foot high by 6 ft wide pile I use four 1/2″ PVC tubes injected horizontally into the pile evenly paced. This injects Air containing O2 into the pile. If you have a Thermometer you can see the temperature jump inside of 10 minutes. This means that the aerobic bacteria is working! if you turn it off, lets say for a day while you make compost tea, you can see the temperature drop significantly as the pile quickly goes anaerobic. Back on again, and so is the aerobic process and the temperature increase. Remember to insulate the sides and the top. Do not seal the Aerobic compost process, but you need to cover and insulate the top from rain, and to assure an even composting process. A great way to make simple fast compost without turning daily.

We have switched to using the drum to mix the materials for both Aerobic with injected air and Anaerobic process. It is a batch system and does not need turned daily. Larger quantities can be made at one time. Originally this unit was designed to compost and turn in the drum and this unit design would provide for 1-2 Hectares. Converting it to an air injected Aerobic process or the Anaerobic process the same unit will make enough compost for 10 hectares.

EM’s will decompose just about any organic product, including manures. The resulting product is sweet smelling and virtually pathogenic free. We do not use any soil in our mix. We use chicken manure waste, rice hulls,(one of the hardest ag waste products to break down) Rice hull ash (a source of Biochar), a small amount of wood ash, waste rice tailings, to provide long term sugar source, some cal, and or rock phosphate, EM and Molasses.

This same process will work with virtually any agricultural wastes and we are getting excellent results from using some of the hardest to breakdown and poorest ag wastes in our process.

Locally, concerns have been raised about antibiotics used in chicken farming. The NOP (National Organic Program- see the ATTRA web site) guidelines are mainly worried about increases in levels of background Arsenic (a mineral). Antibiotics are likely broken down in the process, but bacterial and fungus produce many of their own antibiotics to protect their biological niches.

Lab tests of this Bokashi show NPK of 2:1.5:1 with a full compliment of minerals. You also get your soil inoculated with beneficial bacteria and some beneficial fungi, a great source of carbon, along with a minor amount of pure carbon (Bio-char) from the Rice Hull Ash. I estimate this unit to cost less than $2000 to complete and for my farm had a payback in about 4-5 years. For a 8-10 Hectare farm the payback should be less than 2 years. If the unit was scaled down to a 2 hectare size, the payback would likely be around 2 years as well. For us, the cost of waste agricultural materials is about equal to the cost of transporting them.

All production from this plant is slated for use on our (almost) organic coffee and orange farm. This unit is in its 3rd year of compost production, and we are very happy with the results. I would make some minor changes in the next model; specifically I would insulate the box.

This is an experiment in the use of appropriate technology using locally available materials and methods that can be transferred to subsistence farmers in the region. Recycled materials are used when possible, ferrocement storage area and steel angle iron tracks was chosen for its strength, and material costs. Bamboo was cut locally, treated with a Copper Sulphate solution and wired together using tie wire. Roof is recycled tin. Cheap and Funky increase the technology transfer potential and the payback of the project.

If this project looks like it was made by some poorly educated third world subsistence farmer, that’s because, I wanted those people to think they could do it themselves! And running a farm is a business where cost effective and appropriate technologies are important.

The system is easily scale-able to meet the needs of any farm.