Microalgae in paddy rice fields: influence of different fertilization treatments in areas with residual herbicides of the imidazolinone group

The study evaluated the effect of different fertilization treatments in paddy rice fields on the community composition of epiphytic and planktonic algae in areas with residual herbicides of the imidazolinone group. The experiment consisted of ten treatments of different forms of fertilization and a control in two rice cultivars, one tolerant and one non-tolerant to the herbicide. Were identified 93 species for the epiphyton and 151 for the phytoplankton. No significant differences were found in taxonomic composition and cell density among the treatments, but there was an increase in epiphytic and phytoplanktonic cell density with increased solar radiation towards the end of the crop cycle due to slower growth of the non-tolerant cultivar residual herbicides.