EN
In the six-year field experiment on the weakly loamy sand the increasing (from 0 to 800 tons per hectare) rates of hard coal fly ash were appplied. The ash treatments were used in the four experimental series e.i. without organic substance, manure, cereal straw and tree bark. Increasing ash rates have increased magnesium contestations in crops as in the soil. However, the utilization of this nutrient appeared to be relatively low.