Optimization of nutrient management and biostimulant application in NFT hydroponics to improve yield efficiency and profitability of lettuce (Lactuca sativa L.) cultivation

Abstract

Abstract Optimizing nutrient management and the use of biostimulant are key strategies for improving the productive and economic efficiency of hydroponic systems. This study aimed to evaluate the effects of nutrient solution concentration and biostimulant type on the yield and profitability of lettuce (Lactuca sativa L.) grown in a nutrient film technique (NFT) hydroponic system. The experiment was conducted using a completely randomized design with a 2 × 3 factorial arrangement, comprising two nutrient solution concentrations (75 and 100%), two biostimulants (amino acids and seaweed extract), and a control without biostimulant application. Growth, biomass, foliar nutrient concentrations, yield, and profitability were evaluated. Nutrient solution concentration significantly affected growth and the foliar concentrations of nitrogen, phosphorus, potassium, and calcium, with higher nutrient concentrations under the 100% nutrient solution. However, the 75% nutrient solution produced yield and profitability values similar to those obtained with the 100% nutrient solution. Seaweed extract significantly increased yield and profitability regardless of nutrient solution concentration. A strong positive correlation was also observed between shoot fresh weight and yield. These results indicate that a moderate reduction in nutrient solution concentration and the application of seaweed extract may contribute, as independent strategies, to improving the productive and economic efficiency of lettuce cultivation in NFT systems.