Use of sludge from fish ponds in the production of Pitanga seedings (Eugenia Uniflora l.)

Abstract

The objective of this work was to evaluate the use of sludge from fish farms in the production of seedlings of pitanga, Eugenia uniflora L., through the Agriculture - Aquaculture Interaction (IAA) sistem, as a way to mitigate the environmental impact caused by fish farming. For the evaluation of the sludge composition, samples were collected from a fish pond and analyzed the physicochemical variables, organic matter, moisture, carbon/nitrogen ratio and macronutrients. The sludge was applied to the soil, in different proportions, to verify the growth of seedlings in a greenhouse. The experimental design was completely randomized, with four blocks, each block containing five treatments and four replications. The experimentation phase ended after 80 days of cultivation, when the seedlings reached a height of around 20 cm. Subsequently, the total length, stalk diameter and number of leaves of each seedling were measured. The study showed that as the sludge levels in the fish pond increased, there was an increase in seedling development. The treatment with 100% inclusion of sludge had the best yield, with the following results: 28.03 cm mean total length, 1.81 mm mean stalk diameter and 18.18 mean number of leaves. Organic matter and macronutrients found in nursery sludge can be made available to plants as an economically viable soil conditioner, providing productivity gains. The research provided subsidies for the use of sludge residues from the bottom of the nurseries in the production of seedlings. For the development of a sustainable fish farming, it is essential to use the waste generated by the fish pond in agriculture, enabling its mitigation and the correct disposal of this waste.