Questions & Answers about Effective Microorganisms (EM)

• What is EM?

Effective microorganisms or EM are mixed cultures of beneficial microorganisms that can be applied as inoculants to increase the microbial diversity of soils and plants which, in turn, can improve soil health, and the growth, yield, and quality of crops.

• Where did the concept and technology of EM originate?

The concept of inoculating soils and plants with beneficial microorganisms to create a more favorable microbiological environment for plant growth has been discussed for decades by agricultural research scientists. However, the technology behind this concept and its practical application have now been significantly advanced by Professor Teruo Higa, at the University of the Ryukyus in Okinawa, Japan.

• Are the microorganisms that comprise the EM formulations exotic or engineered organisms?

No, EM cultures do not contain any exotic or engineered microorganisms. EM is made up of mixed cultures of naturally occurring species of organisms that are found in natural environments worldwide.

• If EM cultures contain only microorganisms that occur in nature, what is the advantage of using EM?

Professor Higa has devoted much of his scientific career to isolating and selecting different microorganisms for their beneficial effects on soils and plants. He has found organisms that can coexist in mixed cultures and that are physiologically compatible with one another. When these cultures are introduced back into the natural environment, their individual beneficial effects are greatly magnified in a synergistic fashion.

• What kinds of beneficial microorganisms are contained in the EM cultures, and what are their functions?

EM contains a diverse mix of coexisting microorganisms. Main families are; Lactic Acid Bacteria, Photosynthetic Bacteria, Yeasts, Ray Fungi, other Fungi.

• How does EM actually work?

There is documented scientific evidence to indicate that EM cultures can (a) suppress soil-borne pathogens, (b) accelerate the decomposition of organic wastes and residues, (c) increase the availability of mineral nutrients and useful organic compounds to plants, (d) enhance the activities of beneficial, indigenous microorganisms, e.g., mycorrhizae, (e) fix atmospheric nitrogen, and (f) reduce the need for chemical fertilisers and pesticides. Actually, EM tends to simulate the 'rotation effect,' a term used by agronomists to describe the regeneration of beneficial soil microorganisms and suppression of harmful ones which results from crop rotation.

• Don't some of these 'good' things also happen when naturally-occurring organic wastes are returned to the soil?

Most organic wastes including animal manures and composts do have an indigenous population of microoganisms. Many of them are beneficial, while others are not. However, upon introduction to the soil they are soon overwhelmed by the existing soil microorganisms which again become dominant. Thus, the beneficial effects of microorganisms introduced with the application of organic wastes are often short lived.

• Are EM cultures not subject to the same fate when applied to the soil environment?

Yes, to some extent, but the advantage of EM is that beneficial microorganisms in much greater numbers, and in optimally-balanced populations, are introduced at the time of application. And, if organic substrates are available, they remain dominant in the soil for a much longer time.

• How can the residual effectiveness of EM be extended in soils?

Research has shown that this can be achieved by applying EM about three times (at 8 to 10-day intervals) during the first 3 to 4 weeks after planting a crop. This will insure that EM populations remain high throughout this critical a period when young seedllngs and plants are so vulnerable to environmental stresses (drought, heat, weeds, and pathogens). This is when the greatest loss in crop yield and quality occurs. Once through this critical period, the EM treated plants are vigorous and healthy and can easily cope with stress.

• Can EM cultures enhance the quality of organic wastes and residues?

Yes, EM cultures have been used effectively to inoculate both farm wastes as well as urban wastes to suppress malodors and hasten the treatment process. EM has also been used with great success as an inoculant for composting a wide variety of organic wastes.

• Are EM cultures effective on all soils and crops?

Research on EM has been conducted on many different soils and crops over a wide range of agroecological conditions. Results indicate that in most cases EM has given positive results.

• Can EM technology be considered as a substitute for other management practices?

No, EM is not a substitute for other management practices. EM technology is an added dimension for optimising our best soil and crop management practices such as crop rotations, use of organic amendments, conservation tillage, crop residue recycling, and biocontrol of pests. If used properly, EM can significantly enhance the beneficial effects of these practices. EM-mediated processes can improve the growth, yield, and quality of crops, and the tilth, fertility, and productivity of soils, and reduce the need for chemical fertilisers and pesticides.

• How much does EM cost?

EM inoculants are now being formulated in many different countries, the cost is based on cost of production within each country. The aim and philosophy is to make the product available as cheaply as possible, so that cost is not a barrier to use.

• Is EM certified for use on organically-grown crops?

Microbial inoculants are generally on the allowed materials list of certifying authorities. In New Zealand EM has Bio-Gro certification as an approved product (Click here for BioGro Certificate)

• Since EM helps to control insects, nematodes, diseases, and weeds, is it a pesticide?

No, EM is not a pesticide and contains no chemicals that could be construed as such. EM is a microbial inoculant that func tions as a biocontrol measure in suppressing and/or controlling pests through the introduction of beneficial microorganisms to soils and plants. Pests and pathogens are suppressed or controlled through natural processes by enhancing the competitive and antagonistic activities of the microorganisms in the EM inoculants.

• What are the different variations of EM?

EM•1 is the original solution that is shipped out from your supplier. EM-A is activated extended EM, made from the original solution and extended out 20 times to activate and increase the economics of EM, making it very cost effective.

• How can I get some EM to try out? How can I order EM? How can I get more information and technical assistance for using EM?

You can purchase our products directly from this website using shop or for more information and detailed advice contact us