Produção de Lemna valdiviana com fertilizante orgânico comercial para aquicultura

Abstract

Fishmeal is a product used in fish, pork and poultry feed due to its high nutritional value. Due to high demand, new, economically viable, simple-to-process alternative protein sources that can replace fishmeal are increasingly needed. In natural environments, aquatic macrophytes are an important food resource for birds, fish and insects. These plants in animal feed, especially fish, have been shown to be a promising alternative due to their low cost, ease of production and food quality. The objective of this study was to evaluate the development of Lemna valdiviana submitted to different nutrient concentrations using commercial organic fertilizer for fertilization through a simple production system to be developed in the rural property. The experiment was carried out in a completely randomized design with four treatments and three replications. The treatments were: T1 - 0.012 g.m-3 Nitrogen, T2 - 0.016 g.m-3 Nitrogen and T3 - 0.022 g.m-3 Nitrogen, besides the Control Treatment (C), without fertilization. The following variables were analyzed in the cultivation water: pH (lowest average value was 7.0 and maximum 8.0), temperature (minimum average 30.0oC and maximum 38.0oC) , N-nitrite (N-NO2), N-ammonia (N-NH3) at 1, 7 and 21 days of experiment. Also analyzed were the production of dry biomass: T1 –13.6 t / ha / year; T2 - 14.0 t / ha / year; T3 - 18.5 t / ha / year and C - 5.7 t / ha / year, as well as crude protein content. The crude protein levels achieved in this study indicate a good development of L. valdiviana with 24.58%, with the possibility of productivity improvement by adjusting the method and fertilization dosage.