Alternativas para o aproveitamento da biomassa de macrófita aquática Azolla pinnata R.Br.

Abstract

The present work aims to investigate the development of Azolla pinnata in cultivation, its partial composition and its effects at different concentrations when incorporated as a substrate in the production of lettuce seedlings. This work updates accumulated scientific and practical knowledge, with emphasis on the morphological and physiological characteristics of symbionts, highlighting their ability to fix nitrogen and their biochemistry. Additionally, the protein content of 26.1% highlights this significant potential as a sustainable and efficient protein source. The contents of sodium of 2.69 g/Kg, potassium of 47.5 g/Kg, calcium of 2.16 g/Kg, lithium of 282 mg/Kg, and phosphorus of 17.6 mg/Kg, make this plant valuable for a wide range of applications, from biotechnology, animal nutrition to improving soil fertility, highlighting its potential as a multifunctional resource in sustainable agricultural and ecological practices. Finally, Azolla pinnata, with a sulfur content of 3.54 g/kg, shows a reasonable consistency in its chemical composition. The experiment was carried out from August 2023 to June 2024, at the Federal University of Fronteira Sul , on the Laranjeiras do Sul campus. It is carried out in 2 stages, the first being the cultivation of A. pinnata and the second its use incorporated as a substrate in plastic trays. The experimental design used was the DIC (completely randomized design), with four treatments: T1: 100% vermiculite; T2: 80% Azolla and 20% vermiculite; T3: 60% Azolla and 30% vermiculite; and T4: 30% Azolla and 70% vermiculite, with 11 repetitions. The seedlings were evaluated 25 days after sowing, with the following characteristics being evaluated: shoot length, root length, fresh mass of the shoot and root and dry mass consecutively; in each treatment, six plants were evaluated. Based on the characteristics evaluated, the treatment that presented the best result was T4, presenting the best result in fresh mass of the root and aerial part and best result in dry mass of the root, followed by T3, which came in second place in terms of fresh mass of the aerial part.