Two P biofertilizers described by M. Jastrzvbska et al. (2016) were compared in field expts. on winter wheat to superphosphate. Plant d. after sprouting, general and productive tillering, stem length, the no. of plant leaves, leaf dimensions, ear length, mass of grain from ear, photosynthesis and transpiration intensities were detd. The tested fertilizers did not influence any morphol. attributes, but the mass of grain. Biofertilizers were equally or more effective in grain filling as superphosphate. They usually affected photosynthesis and transpiration intensities at the same or at a higher level than superphosphate at the same P2O5 dose. The ash-based biofertilizer used at a P2O5 dose of 60 kg/ha resulted in the same photosynthesis intensity as superphosphate applied at 80 kg P2O5. However, it reduced photosynthesis rate when applied at a highest dose.