Inoculation effects of Nitrospirillum amazonense and biofertilizer in sugarcane

Efeitos da inoculação de Nitrospirillum amazonense e biofertilizante em cana-de-açúcar

ABSTRACT:

In this study, we analyzed the hypothesis that the combination of Nitrospirillum amazonense strain BR11145 with biological fertilizer prepared using Microgeo^® and native microbiome from location of the product application results in morphological and nutritional gains for the initial development of sugarcane plants and soil chemistry. For this purpose, pre-sprouted sugarcane seedlings were grown in a greenhouse mesocosm experiment using soil amended with nitrogen/phosphorus/potassium fertilizer. The experimental treatments consisted of: 1) biological fertilizer with the addition of N. amazonense (100 mL ha^-1), 2) biological fertilizer without the addition of N. amazonense, 3) inoculation with N. amazonense at a dose of 100 mL ha^-1 with 2x10⁸ viable cell mL^-1, 4) inoculation with N. amazonense at a dose of 200 mL ha^-1 with 2x10⁸ viable cell mL^-1, and 5) control, without the addition of biological fertilizer and N. amazonense. The biological fertilizer was applied at dose of 300 L ha^-1, which was split at planting (200 L ha^-1) and in the post-emergence phase (100 L ha^-1). After 164 days of planting, it was detected an increase in leaf length +3, number of green leaves, leaf area and sulfur content in the leaves of sugarcane plants that received the biological fertilizer with the addition of N. amazonense. In conclusion, the combination of N. amazonense with biological fertilizer revealed positive effects through morphological and nutritional characteristics in sugarcane plants during their early stages of development when compared to plants grown only with the inoculation of N. amazonense, biological fertilizer or mineral fertilizers, with few notable positive effects on soil chemistry.

Key words:
Diazotrophic bacteria; plant-bacteria interaction; soil microbiome; microbial inoculants