RHIZOSPHERE NITROGENASE ACTIVITY AND TRITICALE YIELD IN MIXED CULTURES OF NITROGEN-FIXING MICROORGANISMS

Five different mixed nitrogen-fixing cultures were isolated, and their effect on nitrogenase activity in the triticale rhizosphere, grain yi eld, soil nitrogen content, and nitrogen removal from soil was studied in greenhouse experiments on Gray Forest Soil. Application of a mixtu re of bacilli and yeasts to the soil in the presence of potassium phos phate fertilizer resulted in higher yield and self-supporting nitrogen balance. Nitrogenous fertilizers significantly inhibited associative nitrogen fixation in the majority of the studied mixed cultures, the m icroorganisms themselves inducing nitrogen gas release from N-15-ferti lizers.