RESEARCH ON NITROGEN-FIXING BACTERIA  AND THE DEVELOPMENT OF PRODUCTS CONTAINING NITROGEN-FIXING ORGANISMS IN CONTEMPORARY LITERATURE

Attila Fodora,*, József Iváncsics^b, Tünde Takács^b,^c
aSzéchenyi István University, Antal Wittmann Multidisciplinary Doctoral School of Plant, Animal and Food Sciences, Vár tér 2, 9200 Mosonmagyaróvár, Hungary
^bDepartment of Plant Sciences, Albert Kázmér Faculty of Agricultural and Food Sciences in Mosonmagyaróvár, Széchenyi István University, Vár tér 2, 9200 Mosonmagyaróvár, Hungary
^cInstitute for Soil Sciences, Centre for Agricultural Research, HUN-REN, Fehérvári út144, Budapest, Hungary
 fodorattila@freemai

Abstract: This work provides a comprehensive overview of research on nitrogen-fixing microorganisms from their discovery to the present, with a particular focus on the development of inoculants containing these organisms. Scientific interest in nitrogen-fixing bacteria began to increase in the late 19th century, with early studies concentrating on their nitrogen-assimilation functions. By the early 20th century, systematic research was underway to clarify the ecological and agricultural significance of these microorganisms, assess the efficiency of their nitrogen-fixing mechanisms, identify their biotic and abiotic requirements, and develop methods to enhance their efficiency. Research in the 1960s shifted its focus toward enhancing the nitrogen-fixing capacity of nitrogen-fixing plants and inoculating them with nitrogen-fixing agents. From the 1970s onward, new research perspectives and approaches emerged. Since the 1980s, plant and soil conditioning preparations containing nitrogen-fixing microorganisms have appeared in the market, and their numbers increased significantly in the 1990s and 2000s, although their nitrogen-fixing capacity could not be quantified at that time. By the end of the 2010s, preparations containing endophytic nitrogenfixing bacteria emerged. These bacteria multiply by entering the tissues of the host plant through gas exchange pores after spraying, providing a significant amount of 20-40 kg/ha of fixed nitrogen. These new developments are important for agriculture because they are not species-specific and provide the nitrogen demand of agricultural production in a quantifiable way - partially or completely. From a sustainability perspective, it is important that the use of these products can partially replace nitrogen fertilizers, which are not only harmful to the environment in terms of production but also in terms of their release into nature.