Treated domestic sewage as a nutrient source for strawberry under hydroponic cultivation

Abstract

Purpose This study aimed to compare the hydroponic strawberry production using the conventional nutrient solution and treated domestic sewage, seeking fertilizer savings and identifying its nutritional status and physicochemical and microbiological attributes of fruits.Method The experiment was carried out in a greenhouse under the nutrient film technique (NTF) hydroponic system, with three treatments: DW – drinking water and chemical fertilizers, TDSS – treated domestic sewage supplemented with chemical fertilizers, and TDS– only treated domestic sewage. Each treatment consisted of four cultivation benches, a motor pump system, a timer, and a 500-L container to store nutrient solution. Four hydroponic profiles with a capacity for 12 plants were used on each bench, totaling 48 plants per bench and 192 plants per treatment. These benches were divided into four randomized blocks. We compared the nutrient content of treated domestic sewage to the conventional nutrient solution, amount of nutrients used in treatments, microbiological quality and quantitative and qualitative aspects of fruits, nutritional status of plants.Results The TDS treatment showed a significant difference compared to the others, with visual symptoms of nutritional imbalance in plants, lower productivity, and fruits more acid with a smaller diameter. Soluble solids content showed no statistical difference between treatments and the microbiological quality of fruits, which showed no presence of Escherichia coli.Conclusion The use of treated domestic sewage to compose the nutrient solution allowed obtaining savings of 33% in chemical fertilizers in the TDSS treatment compared to DW.