Impact of EM on the Biological and Chemical aspect of the soil

Soil fertility depends on three major interacting components: biological, chemical and physical fertility. This article is going to look at how EM will affect these areas through increasing soil biology, mobilising nutrients and increasing soil humus content and shows supporting trial data.  

Effect of EM on Biology

Large numbers of microorganisms exist in the soil. One gram of soil contains anywhere from a few hundred million to several billion microbes. Microorganisms are a fundamental component of the ecosystem and facilitate its functioning by breaking down organic substances and circulating nutrients. However, when the quantity of healthy microorganisms in the soil decreases or the balance is disrupted, other living things such as earthworms will be negatively affected and the soil will become impoverished. The diversity of microorganisms contained in EM and the metabolites they produce will increase the number and diversity of microorganisms in the soil. When microorganisms are activated, protozoans and larger organisms such as worms will increase in number and a healthier ecosystem will result. This trial conducted by EM creator Professor Dr Terou Higa and Dr Gene Widdiana at the University of Ryukus in Japan looked at the changes in the Soil Microflora Induced by EM. In the study EM cultures increased the number of Enterobacter spp. and starch digesting bacteria in soil.  A combination of different EM products markedly suppressed the number of Verticillium, Thielaviopsis, and Fusarium fungal species that are destructive soil borne plant pathogens. Some of the EM cultures significantly increased the population of Trichoderma and Penicillium species that are known to suppress plant pathogenic fungi in soils: Soil physical properties, including cultivation depth and porosity, were generally improved by EM treatment.


In another trial conducted in Korea the effect of EM on the number of microorganisms in the soil was measured. The below table shows that the EM treatment increased the number of aerobic bacteria, nitrogen-fixing bacteria and actinomycetes 10.5, 17.8, 49.6, and 1.7 times over the control, respectively.


Effect on Soil Chemical Properties

The long-term soil amendments caused significant changes in soil physical-chemical properties (Table 1). Soil bulk density and pH were significantly (p < 0.05) lower in the two compost plots than in the control plot. Moreover, soil pH was significantly (p < 0.05) lower in the EM compost plot than in the traditional compost plot. Soil organic matter, total N, alkaline-hydrolysable nitrogen, and available K content was significantly (p < 0.05) higher in the two compost plots than in the control plot. Soil available P and K content was significantly (p < 0.05) higher in the EM compost plot than in the traditional compost plot.

In another trial conducted in Korea looked at the effect of EM treatment on the content of nutrients in the soil. The EM treatment increased the content of soluble nutrients, the contents of soluble nitrogen, phosphorous and potassium increased 4.4, 3.6 and 2.8 mg/100g soil, respectively. pH o the soil treated with EM was 0.1 higher than the control. The increase of soluble N, P and K contents might be attributed to activity of nitrogen fixers and organic acids excreted by the different organisms in EM.

Improving the Soils Physical Properties

EM is applied to the soil to accelerate the soil building process and promote beneficial microbial communities.  The soil building process revolves around soil aggregate formation. Soil aggregates form as mineral and decomposed organic matter particles are bound together by microbial secretions that act as glues. Stable and well-formed soil aggregate is the key to overall soil function. For EM to function effectively it is important to have organic matter in the soil to feed the microbes and biological activity. Humus is an important part of this and improving humus should be at the forefront of every farmers mind. In this trial from the Złotów district in Poland looked at the impact EM has on the humus content of the soil. EM was applied on crop residues (straw 100% plowed) over three years of application. This treatment was across 50 hectares with a large control area. After 3 years soil was tested for the humus content and the results showed EM significantly increased the humus content with the soil. This shows the impact EM will have in converting crop residues and organic matter in your soil into humus.