effective microorganisms; EM
Technical term in agriculture and environmental science referring to a mixed culture of beneficial microbes. Often abbreviated as EM.
Applying effective microorganisms to the soil can sometimes improve crop growth.
EM (effective microorganisms) is also used for environmental cleanup.
有用微生物群 is the full Japanese term for 'effective microorganisms', while ＥＭ is its common abbreviation used in the same technical contexts.
Compound of 有用 (useful) + 微生物 (microorganism) + 群 (group). A modern technical coinage, likely calqued from English 'effective microorganisms'.