MgSO4 was added to 3 conn. gertilizers based on NH4NO3 and contg. various amts. of dolomite or anhydrite to study the soil pH, content of nutrients in soil as well as yielding maize, oats, barley and wheat in pot expts. The addn. of MgSO4 to fertilizers with dolomite resulted in an increase in plant yields. In contrary, a decrease in the yields was obsd. for fertilizer with anhydrite.