The importance of diazotrophs as biofertilisers in the maize and soybean production

The contemporary food production requires the preservation of soil productivity with the simultaneous maintenance of the yield level accomplished with the appropriate fertilizing. The maize and soybean production is unimaginable without fertilizers and the application of information within the filed of nitrogen fixation. The application of fertilizers has been increasing. Diazotrophs are microorganisms with the ability to fix atmospheric nitrogen and to convert it in forms available to plants. Therefore, effects of different rates of mineral nitrogen (80, 120 and 160 kg N ha-1 in maize and half of the mentioned rates in soybean), as well as, maize seed bacterisation with the associative species (Azotobacter chroococcum, Azospirillum lipoferum, Klebsiella planticola, Beijerinckia derxi) and soybean with the symbiotic species (Bradyrhizobium japonicum) and their mixture on soil biogeny and yield quality and quantity were studied. The studied parameters in maize had higher values under conditions of bacterisation and fertilization with 80 kg N ha-1, while the mixture of diazotrophs and fertilization with 40 kg N ha-1 resulted in higher values of studied parameters in soybean. It is possible to produce organic/healthy food with the maintenance of soil biogeny if diazotrophs are incorporated into the soil with lower rates of mineral nitrogen. This possibility is a basic prerequisite for sustainable agriculture.