Effects of the application of biofertilizers on the microflora and yield of lettuce (Lactuca sativa L.)

Recently, biofertilizers are recommended as an alternative or supplement for mineral nutritients. Active agents in biofertilizers are microorganisms that are involved with their activity in the preparation of herbal assimilative and other biotic substances for plant needs. In this study, the influence of Bioaktiv bioproduct on the lettuce yield and rhizosphere microflora of lettuce was tested. 'Bioaktiv' contains the active substance consisting of following microorganisms: Bacillus subtilis, Azobacter sp., Penicillium oxalicum and Fusarium sp. In the tested soil samples of lettuce rhizosphere, the total number of bacteria, Azotobacter sp., ammonifiers, oligonitrophyls, actinomycetes and fungi were determined. The total number of bacteria, Azotobacter sp., ammonifiers, oligonitrophyls, actinomycetes was increased while the number of fungi in the variant with biofertilizer was slightly lower than in the control variant. The application of this bioproduct affected on earlier formation of the lettuce head and overall higher yield.