This trial (Filarski, 2016) on frites potato was conducted by Agricultural Holding Henryk Makoś, Lebork, Poland. The results showed that EM gave a signfiicant increase in yield over the fertilised control with an increase of over 7 tonnes per hectare. In additon EM had 2% higher percentage of potatos above 50mm.
Filarski, A. (2016). Field Experiments Report - Poland. Greenland Technologia EM.