Importance of microbiological fertilizer used in soybean production: Agronomical and biological aspects

Abstract

Inoculation is the best way to ensure good nodulation with the proper strain of nitrogen-fixing bacteria for increased
yield in an environmentally safe manner. This investigation was conducted on three -year experiment which was set
up in four replications with three-crop rotation (maize-soybean-wheat) at experimental field of the Institute of Field
and Vegetable Crops, Novi Sad, Serbia. Effects of application of microbiological fertilizer (with nitrogen-fixing
bacteria Bradyrhizobium japonicum) on root mass, number and mass of nodes per plant, soil biogeneity (number of
ammonifiers, Azotobacter, actinomycetes), as well as the effect on soybean yield were studied. Obtained results
indicated positive impact of inoculation on nitrogen fixation parameters. The higher amounts of mineral nitrogen
had negative impact on atmospheric nitrogen fixation, that is, by increasing preplanting mineral nitrogen amount in
the soil by 1 kg, the amount of calculated nitrogen from the air was decreased by 1.72 kg. Increasing abundance of
studied microorganisms in the rhizosphere, as well as soybean yield using microbiological fertilizer was stimulated
by plowing under crop residues. The impact of meteorogical conditions on the effects of inoclutaion was very
significant.
Key words: I