Effects of growing spring barley in organic agriculture as a result of constructed bacterial consortia and living mulch

The objective of the research conducted in a temperate climate was to determine the effect of bacterial consortia in spring barley cultivated with living mulch on grain yield, grain yield structure, and the biological index of soil fertility.The experiment was conducted with the following two factors: bacterial consortia: control, inoculation with Azospirillum lipoferum Br17 and Azotobacter chroococcum, inoculation with Pseudomonas fluorescens, Bacillus subtilis, and Bacillus amyloliquefaciens, and inoculation with Azotobacter chroococcum, Pseudomonas fluorescens, Bacillus subtilis, and Bacillus amyloliquefaciens; living mulch: control, red clover, red clover and Italian ryegrass, Italian ryegrass.The highest spring barley yield characterized by the best biometrical characteristics of the ear and 1000-grain weight was recorded in the treatment with Azotobacter chroococcum, Pseudomonas fluorescens, Bacillus subtilis, and Bacillus amyloliquefaciens.Of the tested living mulch, the most favorable effect on grain yield and its structure was associated with the living mulch of red clover mixed with Italian ryegrass.Organic growers should be encouraged to apply the technology of cultivating spring barley with a mixture of red clover and Italian ryegrass used as living mulch following an application of Azotobacter chroococcum, Pseudomonas fluorescens, Bacillus subtilis, and Bacillus amyloliquefaciens, as it contributes to the highest grain yield with good yield structure while preserving the highest soil fertility.K e y w o r d s: spring barley, plant growth promoting rhizobacteria, living mulch, yield, biological index of soil fertility