In a small-plot field experiment, two soybean (Glycine max L.) cultivars were grown on a calcareous chernozem under the drought conditions of 2012 with the preplanting application of simple superphosphate (P_s) at 60 kg/ha, urea (N_u) at 10 and 20 kg/ha, and ammonium nitrate (N_an) at 20 kg/ha. The phosphatase activity was measured in the rhizosphere soil (0- to 20-cm layer) and the fine nonlignified roots of soybean plants at the blossoming and pod-formation stages (the soil water content was 19 and 33% of the total water capacity, respectively). The maximum content of available phosphorus in the rhizosphere of both soybean cultivars (4.3–4.8 mg/100 g dry soil) was found at the simultaneous application of P_s and N_u20. Higher activities of the predominant phosphatases (alkaline phosphatase in the rhizosphere and acid phosphatase in the roots) were observed in the root-inhabited zone of the soil under the Indra cultivar compared to the Aura cultivar, which correlated with the lower content of available phosphorus in the rhizosphere soil (especially at the simultaneous application of P_s and N_u20) and the higher productivity of this cultivar in this treatment.