These studies are based on a field experiment carried out in the years 2011-2016 at RZD IUNG-PIB in Grabów. The experiment consisted of three crop rotations differing with respect to leguminous crops included in these rotation, reflecting three different types of ecological (organic) farms. Crop rotation A, representing a dairy farm, consisted of: maize - cerealpulse mixture (undersown with grass-red clover) - grass-red clover ley (year I) - grass-red clover ley (year II) - winter wheat. Crop rotation B, representing a pig farm, included: maize - spring barley - cereal-pulse mixture - pea - winter wheat. Crop rotation C, representing a farm without livestock, consisted of: maize - cereal mixture - spring wheat (undersown with red clover) - red clover - winter wheat. The objective of this study was to assess the presented crop rotations with respect to their productivity and effects on yields of particular crops and basic soil fertility indicators. Among the compared rotations the highest productivity in terms of cereal units was obtained in the case of crop rotation A representing the dairy farming system, and the lowest productivity in the case of rotation B representing the livestock (pig) farming system. During the 6-year experimental period no significant differences were found between the compared rotations with respect to phosphorus content in the soil. Potassium contents in the soil of rotations A and C were lower than in rotation B. The compared ecological farming systems had minor effects on soil microbial activity indicators. Dehydrogenase activity and glomalin contents were lowest while hot water extracted C was highest in the soil of rotation B as compared to the soil of rotations A and C.