Effect of different doses of Ajinomoto fertilizer on the dynamics of Cyanobacteria during a rice (Oryza spp.) growing cycle in the Korhogo Region, Côte d’Ivoire

This study investigated the effects of different fertilization treatments on the dynamics of Cyanobacteria in irrigated rice fields in northern Côte d’Ivoire. Sampling was conducted in an experimental Fisher block design comprising four treatments: control (FT1), mineral fertilization (FT2), combined mineral and Ajinomoto fertilization (FT3), and Ajinomoto alone (FT4). Environmental variables and Cyanobacteria communities were monitored throughout the rice-growing cycle.
A total of 21 Cyanobacteria species belonging to 11 genera were identified, all within the class Cyanophyceae. The order Oscillatoriales was dominant. Cyanobacteria abundance was significantly higher in FT3, which also showed the highest nutrient concentrations. Oscillatoria limosa was the dominant taxon across all treatments. Statistical analyses revealed significant relationships between Cyanobacteria genera and environmental variables, particularly nutrients and conductivity.
These results highlight the influence of fertilization regimes on Cyanobacteria communities and suggest that combined fertilization enhances cyanobacterial development, with potential implications for sustainable rice production.