Impact of the combined use of chemical fertilizer and microbial inoculants on soil properties, yield and quality of Burley tobacco
Radka Bozhinova, Tsveta Hristeva
Abstract: The effects of three commercial microbial inoculants Europlus® (Italy), Micotric L® (Italy) and Rhizo-Vam Basic® (Germany), applied in combination with mineral nitrogen fertilizer, on the soil agrochemical and biological properties, absorption of nutrients, yield and quality of Burley tobacco were studied in field experiment set on Rendzic Leptosol. The microbial products contain arbuscular mycorrhizal fungi of the genus Glomus. The experimental design was a randomized complete block replicated three times.
It was found that the tested microbial products had a positive effect on soil properties, with less definite on agrochemical than on biological properties. The average population density in the rhizosphere microbial communities increased significantly under their influence. The changes affected mainly the trophic groups of soil microorganisms which performed the processes of ammonification and immobilization of mineral nitrogen. The combined application of microbial products with mineral nitrogen fertilizer provided a more favorable nitrogen regime in the soil than self-mineral fertilization and improved the absorption of basic nutrients by tobacco plants in general. Microbial products increased the content of macronutrients (N, P, K, Ca and Mg) in tobacco. The concentration of Zn and Cu in the leaves also increased with their use. Microbial inoculants increased the yield and the quality of the dry tobacco. The highest yield was obtained with the products Rhizo-Vam Basic and Micotric L, and the highest quality with the products Europlus and Micotric L. Micortic L was the most suitable bio-fertilizer for Burley tobacco from agricultural aspect. The yield increased by 7% and the quality of the tobacco raw material by 37%. The degree of root colonization with arbuscular mycorrhizal fungi and the established positive statistically significant correlations with the content of macronutrients in tobacco plants showed that the tested microbial products can be successfully used in the development of environmental-friendly technologies for Burley tobacco cultivation.
It was found that the tested microbial products had a positive effect on soil properties, with less definite on agrochemical than on biological properties. The average population density in the rhizosphere microbial communities increased significantly under their influence. The changes affected mainly the trophic groups of soil microorganisms which performed the processes of ammonification and immobilization of mineral nitrogen. The combined application of microbial products with mineral nitrogen fertilizer provided a more favorable nitrogen regime in the soil than self-mineral fertilization and improved the absorption of basic nutrients by tobacco plants in general. Microbial products increased the content of macronutrients (N, P, K, Ca and Mg) in tobacco. The concentration of Zn and Cu in the leaves also increased with their use. Microbial inoculants increased the yield and the quality of the dry tobacco. The highest yield was obtained with the products Rhizo-Vam Basic and Micotric L, and the highest quality with the products Europlus and Micotric L. Micortic L was the most suitable bio-fertilizer for Burley tobacco from agricultural aspect. The yield increased by 7% and the quality of the tobacco raw material by 37%. The degree of root colonization with arbuscular mycorrhizal fungi and the established positive statistically significant correlations with the content of macronutrients in tobacco plants showed that the tested microbial products can be successfully used in the development of environmental-friendly technologies for Burley tobacco cultivation.
Keywords: arbuscular mycorrhizal fungi; bio-fertilizers; Burley tobacco; microbiota; nutrients; soil properties
Date published: 2022-03-02
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