How effective are ‘Effective Microorganisms’? Results from an organic farming field experiment

Summary in the original language of the document

The effectiveness of ‘Effective Microorganisms’ (EM) was investigated in a four years field experiment (2003-2006) at Zurich, Switzerland. The experiment was designed to enable clear differentiation between effects of the microorganisms in the EM treatments (Bokashi and EMA) and its substrate (sterilized treatments). Crop yields and soil microbiological parameters as soil respiration and microbial biomass were determined. The EM treatments showed no effect on yield and soil microorganisms which were caused by the EM microorganisms. Observed effects could be related to the effect of the carrier substrate of the EM products. The sampling time showed stronger effects on soil microbial biomass and soil respiration compared to the effect of the treatments. Hence ‘Effective Microorganisms’ are not able to improve yields and soil quality in mid term (4 years) in arable farming under temperate climatic conditions as in Central Europe.