Quality of residue from fry production tanks as soil amendments in semiarid region of Pernambuco State: support for environmental management

Abstract

Inputs of biological origin could act as soil conditioners providing nutrients for plants with low production cost. The incorporation of organic residue to the soil can be an alternative to use these residues for agronomic purposes. The aim of this study was to determine nutrient contents with agronomic value of the residues resulting from fish farming, in the semi-arid of Pernambuco State. The chemical and physical parameters analyzed in the residue samples were: organic matter, humidity at 65° C, carbon:nitrogen ratio and total macronutrients (nitrogen, phosphorus, potassium, calcium and magnesium). The residue samples resulting from fish farming showed a great nutrient reserve for plants and a tendency of higher values compared to those from animal manures, especially K and Mg, which reached 2.5 to 5 times and 2 to 4 times more, respectively.