Soil microbial activity of faba bean (Vicia faba L.) and wheat (Triticum aestivum L.) rhizosphere during growing season

Plant-microorganism relationships in the rhizosphere soil are crucial for nutrient cycling, plant productivity, and health. The study was conducted to assess the effects of faba bean and wheat on enzyme activities and metabolic potential in the soil rhizosphere as well as their changes during the vegetative season. The field experiment was performed on a Haplic Luvisol. Faba bean (Vicia faba L.) cv. Granit (F) and spring wheat (Triticum aestivum L.) cv. Kandela (W) rhizosphere soils were taken for analysis three times during the vegetation. The activities of dehydrogenase, protease, urease, and acid phosphomonoesterase as well as the metabolic diversity of the microbial community were assessed. Although soil enzyme activity was related to the sampling terms, the activities of dehydrogenase, protease, and urease were higher under F than W at the later growth phases. Similarly, metabolic diversity indices were significantly greater under F than W at the flowering stage of faba bean and head emergence of wheat. Significant differences between plants and sampling terms were observed in respect to utilization of different groups of carbon substrates, especially carboxylic acids, amides, and amines. This result demonstrates higher soil microbial activity and functionality in the rhizospheres of faba bean than wheat. The plant effect on soil microbial activity increased with time. This study expands our knowledge of the ecological effects of plant species on interactions between the plant rhizosphere and soil microorganisms.