Simple bio-composting system using bokashi

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By Diana Duff

By Diana Duff

special to west hawaii today

Bokashi, fermented organic matter, has been used for years in Korean and Japanese natural farming. An important ingredient in making bokashi is EM-1. This collection of micronutrients, developed in Japan in the 1980s continues to be researched, providing new ways to improve recycling and gardening practices.

Though bokashi is widely available, you can also make it yourself. The key ingredients are molasses, water and wheat or rice bran, inoculated with the microbes found in EM-1. The ingredients are mixed and fermented for two weeks, resulting in a sweet-smelling product that can be used moist or dried and stored. Bokashi recipes are available online and a step-by-step video is posted at compostguy.com/videos/how-to-make-bokashi.

One of the best ways to use bokashi is in a bio-composting system that makes recycling kitchen waste simple, odor-free and fast. The bokashi composting system can save time and effort over standard composting techniques. This system rapidly ferments food waste into healthy soil additives that can help you grow healthier food.

Waimea flower farmer Ashley Goo describes the system as requiring a few inexpensive parts that will produce valuable garden products quickly. Goo’s system is small and can sit without unpleasant odors on your kitchen counter.

You start the process by placing kitchen waste and all leftovers into an airtight container. Such a container, inoculated with EM-1, is available. The container also comes with an internal strainer that allows the liquids to percolate to the bottom and a spigot to drain off the “tea” for use as part of a microbe-rich foliar spray or soil additive plants love.

For every 2 inches of food waste, sprinkle bokashi on top and mash the combination down to exclude air from the process. The anaerobic fermentation process is hastened and made nearly odorless by the addition of bokashi. Odors that do exist are more sweet-sour as the food waste is literally being “pickled.”

Once the container is full of waste layers, set it aside and let it ferment for three to four weeks. Start another batch or add the interim waste to your outdoor worm or compost bin. During fermentation, drain the liquid from the container and dilute one part “tea” to about 1,000 parts water and spray it on the leaves of plants or water your plants with the mix. The microbes will improve the health of the soil and the health of your plants.

During fermentation, a white mold will likely form on the surface. This is normal. In four weeks, the material should be completely fermented and can be buried in the soil or added to your outdoor compost bin as an inoculant to speed the composting process.

To add the end product to your garden, dig a hole or trench about 1 foot deep. Line the bottom with bokashi, then add the fermented food waste. Sprinkle the top with more bokashi and cover this mix with a foot of soil. After three weeks, the microbes should have multiplied sufficiently so that when you dig into the area you will find a rich, dark soil.

Ashley’s website, earthsmicromiracles.com, has more information on his system and product. His system is available on Saturdays at the Keauhou Farmers Market. Email him at aj.goo@hotmail.com for the location and times of upcoming training sessions.

Master composter Ashley Goo provided information on this system for this column.

Tropical
gardening helpline

Diana asks: I started a new container garden mixing store-bought potting soil and compost 50/50. Some of my plant leaves are turning yellow and my dwarf lemon tree’s leaves are really yellow. They get enough water and I fertilize occasionally with Miracle Gro. What am I doing wrong?

Tropical Gardener answer: Container gardens are a great way to maximize production in a minimal space. They can, however, be a little challenging at first.

Yellowing leaves usually indicate a nutrition problem which originates in your soil. The store bought potting soil may be nutrient deficient and your compost may not be thoroughly broken down. If it is not, it may be using nitrogen in its decomposition process, robbing your plants of this important nutrient. Be sure that you are adding sufficient nitrogen in your fertilization program. If the soil is not nitrogen deficient, the pH may be outside of the range that enables plants to absorb soil nutrients.

An iron deficiency is often the cause of yellowing leaves in citrus. You may find more information on this issue and general information about growing citrus plants at ctahr.hawaii.edu/oc/freepubs/pdf/F_N-14.pdf.

If the pH is too acidic or too alkaline, the nutrients you add may not be available to your plant. The best way to remedy this situation is to test your soil. Home kits are available or you can take a soil sample to the CTAHR Cooperative Extension Service office in Kainaliu and have it tested. An explanatory publication is available at ctahr.hawaii.edu/oc/freepubs/pdf/SCM-9.pdf.

Email plant questions to konamg@ctahr.hawaii.edu for answers by Certified Master Gardeners.

Some questions will be chosen for inclusion in this column.

Parts of the answer to this question were addressed by Certified Master Gardeners at the UH CTAHR office in Kainaliu.

Diana Duff is an organic farmer, plant adviser and consultant.