Cu ore floatation sediment was improved by addn. of sand, phosphogypsum, limestone overlay, waste rock, beech bark, straw, org.-mineral fertilizers, CaCO3 and MgCO3 and used as soil in pot cultures of alfalfa, clover and a mixt. of the plants with several grasses in 5-kg pot expts. carried out for 3 years. The plant tissues were dry incinerated. The ashes were analyzed for P and Cu. The content of Cu was below 25 mg/kg acceptable for feeding purposes. The P content was the highest after the first year of culture (0.10-0.25%) and decreased down to 0.09-0.13% in the third year of the culture.