Effect of fertilizers on the growth performance of Azolla pinnata: A potential feed additive for fish culture in Bangladesh

Abstract

Azolla is among the most popular, low-cost, and high-nutrient-content fish feeds. Azolla pinnata's growth performance was evaluated on the effects of fertilizers containing phosphorus and nitrogen. The study used a completely randomized design (CRD) over thirty-five days in 150 L water containers. Two sets of sub-experiments were established, each with three replications: one for the combined application of phosphorus and nitrogen and another for the sole application of phosphorus. The results showed that the combined application of phosphorus (46% P) and nitrogen (46% N) was more effective than the application of phosphorus alone. The highest cell number and protein content of combined P and N applications were (70.01±4.73 g and 33.71±2.3%) in the T4 treatment. On the other hand, the maximum cell number and protein content of the sole P application were 58.76±3.8 and 33.06±2.25%, respectively, in the T4 treatment. A Significant variation was observed in terms of the mean cell number, weight, and protein content among the experimental treatments. This study's primary focus was to demonstrate the effects of inorganic fertilizers on Azolla growth. The findings suggest that the combined application of phosphorus and nitrogen fertilizer can significantly enhance Azolla growth compared to the sole application of phosphorus.