Effective microorganisms (EM for short) are a mixture of different yeast fungi and bacteria. They are said to have a positive effect on the soil and its composition, primarily in agriculture and in the home garden. The following article shows how and whether EM actually works and how you use the remedies.
What are effective microorganisms and what are they used for?
Effective microorganisms (EM) are a mixture of yeasts, lactic acid bacteria and photosynthetic bacteria that can improve garden soil, strengthen plants and increase crop yields. However, their effectiveness is scientifically controversial and their use as a panacea should be viewed critically.
What are effective microorganisms?
The term “effective microorganisms” (abbreviated EM) stands for a mixture of different microorganisms with different properties. They are supposed to complement each other and partly also feed on the metabolic products of other microbes. The compositions of the microbial solutions differ between different manufacturers, although the exact ingredients are kept secret and therefore cannot be traced.
Basically, EM solutions contain yeast fungi, lactic acid bacteria and bacterial cultures that are capable of photosynthesis:
- Yeast fungi: feed mainly on sugar and other carbohydrates as well as oxygen and release antioxidants, vitamins, enzymes and acids
- Lactic acid bacteria: These bacteria are responsible for the fermentation processes typical of EM, in which starch and sugar are converted into lactic and acetic acid.
- Photosynthesis bacteria: These bacteria provide energy and also break down toxins such as dioxin and nitrate.
The microbes used are both aerobic (i.e. consume oxygen) and anaerobic (i.e. consume nitrogen) and thus complement each other. Finally, the aerobic microbes produce nitrogen and the anaerobic ones produce oxygen, so both species feed each other.
What are effective microorganisms good for?
Effective microorganisms are delivered in a nutrient solution and are diluted with water and applied directly to the plants or garden soil. You should
- improve the soil
- strengthen plant he alth
- Ensure higher crop yields
- Accelerate the decomposition process when composting
Whether the products actually keep the promises made by the manufacturers is a different story. Some gardeners report positive effects, while others have noticed no effects at all.
Discovery and development
The system of effective microorganisms was developed in the 1980s by the Japanese horticultural professor Teruo Higa, whose theses can be read, among other things, in these books he wrote (€24.00 on Amazon):
- A revolution to save the earth. (first published in German in 1993)
- The future regained. (published in German in 2002)
- Effective Microorganisms (EM). (published in German 2005)
The system was created from intensive research to improve the quality of the soil, which should be returned to a natural balance with the help of natural microorganisms. Today, EM is an entire industry that is also intensively promoted outside of Japan and is mainly used in organic gardening.
He althy plants can only grow in he althy soil.
How it works
There are three different groups of microbes found in soil
Behind EM there is a whole theoretical framework of ideas, the main statement of which is: By adding effective microorganisms, the soil-improving activities of all microorganisms are promoted. According to teaching, the microbes can also be divided into three groups:
- building microbes: are contained in EM solutions and are intended to promote soil life and thus ensure better soil quality
- putrefactive and pathogenic microbes: damage the soil quality as they promote putrefactive processes
- opportunistic microbes: Represents the majority of all microorganisms in the soil. They are basically neutral and support either the constructive or the putrefactive microorganisms, depending on which group is currently more active.
The background to this teaching is that the soil is depleted by (conventional) agriculture and the use of plant protection products and fertilizers and is practically “dead” from a microbial point of view. The quality of the soil can only be significantly improved through revitalization, which is why constructive and therefore life-promoting mixtures of microorganisms should be introduced.
These not only work, but also cause the neutral “follower” microorganisms to restore the soil balance and create a he althy soil environment. To do this, the harmful putrefactive bacteria are combated. As a result, the natural cycles resume and plants can grow he althily without any artificial fertilizers and pesticides.
This article shows how effective microorganisms can be used:
Boden verbessern: Helfen effektive Mikroorganismen? | Garten | Unser Land | BR
Application in the garden
Effective microorganisms can be used not only to improve soil, but also in the home and to support healing processes in humans and animals. This wide range of possible applications alone should give rise to suspicion, because no agent - especially none that was developed primarily to improve soil - can be used as a panacea. What is positive for soil life does not necessarily have to be found in cleaning products or on human skin.
It is true that the skin and intestines, for example, are populated by a large number of microorganisms that do valuable work there. However, they are not the same types of microbes, as each form performs virtually different tasks. For this reason, in this section we limit ourselves to the supposedly positive effects of EM on the garden:
EM products, which are available either as a master solution or as finished products, are used diluted or undiluted. The solutions should be applied weekly during the growing season between spring and late autumn. To do this, the user should proceed as follows:
- Pour solution into a watering can.
- Fill solution with water.
- Exact mixing ratio depends on the specific product.
- Watering plants and soil.
EM not only improves the soil and strengthens the plants, making fertilizers and pesticides unnecessary, they also combat acute plant diseases. To do this, the user should apply the solution in a higher concentration directly to the affected plants.
Effective microorganisms are usually diluted, but sometimes they are also used pure
The effective microorganisms strengthen the plants' immune system and also prevent the development of mold. They can be used not only in the garden, but also on lawns, in the greenhouse and even on houseplants. The positive effects also include the fact that beneficial insects such as bees, bumblebees, butterflies and ladybirds are also encouraged.
Excursus
Natural plant protection from the edge of the field
Instead of obscure microbial mixtures, you can also rely on inexpensive and easy-to-make plant manures. These provide your plants with valuable nutrients and actually strengthen their defenses - and this has even been scientifically proven and without you having to open your wallet. Supposed weeds such as tansy, wormwood, field horsetail and nettles are particularly effective.
All you have to do is follow these steps:
- Collect one kilogram of fresh plant material.
- Crush this carefully.
- Put it in a plastic bucket.
- Fill it with ten liters of water.
- Add a handful of primary rock powder.
- Cover the mixture with gauze or jute.
- Place the container in a dark and warm place.
- Stir the mixture daily.
Here, too, an effective decoction is created through fermentation, which is diluted in a ratio of 1:10 and applied to plants and soil. The plants absorb the substances through their roots and experience a direct strengthening of the immune system - without any seemingly esoteric superstructure. Instead of a (admittedly foul-smelling) manure, you can also use a decoction in which the plant material is only left to stand in water for a day. Unlike manure, you don't have to dilute it.
In order to preserve nature, we should avoid using toxic chemicals in the garden as much as possible. Plant and soil protection also works in a completely natural way!
Do effective microorganisms actually work?
The miracle effect of EM is not scientifically substantiated
Basically, it is a good idea to show he althy skepticism towards effective microorganisms. After all, the various remedies are sold at high prices and marketed cleverly. Extremely positive “testimonials” from alleged users are widespread in many forums, but these can usually be traced back to viral marketing – i.e. paid writers. According to these “experience reports”, effective microorganisms should help against everything and anything, which is of course not tenable from a scientific point of view.
In fact, the alleged positive effects of EM solutions could not be proven or could only be proven to a limited extent in various scientific studies. Instead, from the scientists' point of view, any effects on the soil are not due to the microbes, but rather to the highly concentrated nutrient solution in which the microorganisms are found. Studies in which effective microorganisms were also used with distilled water showed no differences to untreated soil.
As always with things that are so strongly praised to heaven, you shouldn't believe everything you read. Feel free to give EM a try; if in doubt, you have supplied your garden with an expensive fertilizer. But maybe the Effective Microorganisms will actually help you?
Excursus
Use earthworms specifically to improve the soil
Instead of expensive nutrient solutions, you can simply use earthworms to improve the soil. These can be purchased from specialist retailers. Place the animals in the freshly dug and loosened bed, add fresh grass clippings and be patient.
This video shows how soil improvement using earthworms works:
Manufacture and products
The EM finished products consist of microorganisms that were cultivated in a multi-stage process based on sugar cane molasses. This causes the sweet molasses to break down and the microbes multiply. In this way, a nutrient solution is created that contains microorganisms and is referred to as “activated EM” (EMa for short). In contrast, the so-called original solution is available as EM-1. In addition to the “good” microorganisms, such a solution also contains:
- various enzymes
- a mixture of vitamins
- and amino acids.
This means that it is actually less of a soil additive and more of a highly concentrated fertilizer, the actual effect of which is less due to the microorganisms it contains and more to the nutrients.
A wide variety of different products are now available, which are primarily sold over the Internet. A liter of solution usually costs between five and ten euros and is enough for an average of ten square meters of floor. Considering that the product is intended to be used weekly for most of the year, it is a fairly expensive type of fertilization. In a 100 square meter garden you will need ten liters of solution per week, which corresponds to an average price of 75 euros.
Given the highly concentrated ingredients, it is not surprising that the solutions in the vegetable garden are primarily recommended for heavy-feeding plants such as tomatoes, potatoes, cabbage or broccoli. Here, users should fertilize the vegetables with 200 milliliters of solution per ten liters of water every two to four weeks.
FAQ
What is Terra Preta and how can you make it yourself?
Terra Preta is also called black earth and has been proven to increase the water storage capacity of the soil. To produce Terra Preta, compost, manure or effective microorganisms, animal manure, rock dust and biochar are mixed together. A detailed application for making and using Terra Preta can be found here.
What is Bokashi and is it actually more nutrient-rich than normal compost?
" Bokashi" is the Japanese term for "fermented organic material" and is therefore a type of compost. This should be produced with the help of effective microorganisms and ultimately used as fertilizer in the garden. The starting material is ordinary, uncooked kitchen and garden waste, which is soaked in an EM solution and finally fermented. This special type of composting prevents the development of putrefactive processes and you no longer need to turn the “compost heap”. A usable fertilizer is created here after about three to four weeks. Bokashi is said to be significantly more nutrient-rich than normal compost, but this has not yet been proven in studies.
When and how much solution should you apply?
If you want to work with EM in your garden, you should apply the solution around four to six times a year. A warm day with temperatures between 15 and 20 °C and an overcast sky is ideal. The microorganisms contained in the solution are sensitive to UV rays, which is why sunshine is not a good idea when applying it. You should plan on one liter of irrigation water with 20 milliliters of solution per square meter of soil.
Do effective microorganisms actually help against snails?
The manufacturers of EM solutions also tout them as an effective remedy against snails. The reason for this is that the ground is full of snail eggs and the animals hatch primarily when putrefactive processes occur. Effective microorganisms would prevent the putrefactive processes and thus there would be fewer snails. Of course, this is nonsense: you won't have fewer snails in your garden just because you water your plants with EM. The same applies to ants, which cannot be driven away with effective microorganisms: at most, the animals disappear because you pour water into their burrows. Ants basically don't care whether it contains microbes or not. Tip: Treatment with effective microorganisms should also help against aphids, for example on roses. To do this, spray infected or endangered plants regularly with the diluted solution during the growing season.
