Effect of azotobacter chroococcum application on production characteristics of sugar beet and microorganisms in sugar beet rhizosphere

Abstract

Effects of Azotobacter chroococcum inoculation on sugar beet production characteristics and microbiological status in the soil were studied on three different methods of sugar beet inoculation with Azotobacter chroococcum strains. The variety Drena was used in the study. Experiments were carried out at Rimski Sancevi in 2008, 2009 and 2010. Five strains of Azotobacter chroococcum were used as microbial inoculants. Three inoculation methods were applied: (A) strain incorporation into the soil before planting, (B) strain application on soil surface before the first inter-row cultivation and (C) seed inoculation before planting. All five Azotobacter chroococcum strains, in each of the three application methods, showed a positive effect on the production characteristics of sugar beet. The highest yield increases in root (6.45 t ha(-1)) and sugar (0.63 t ha(-1)) was obtained on seed inoculated with strain 10.