Ciclagem de macronutrientes no cultivo de alface hidropônica

Abstract

The search for sustainability in agricultural production has been reflected in the management of hydroponic systems that use the Laminar Nutrient Flow Technique (NFT). The reuse of nutrient solutions becomes an alternative to disposing of water and nutrients into the environment since the scarcity of this water resource and soil contamination by fertilizers are both economic and environmental problems experienced worldwide. Therefore, the objective of this work was to test the hypothesis that the nutrient property offers the reuse of discarded nutrient solutions during the development of the hydroponic lettuce crop. The experiment was carried out in an agricultural greenhouse, in an NFT hydroponic system, in two stages (Step 1 - monitoring and data collection and proposition of nutrient alteration management and Stage 2 - validation of the proposed adequacy management). In Step 1, the macronutrients present in the nutrient solution and the lettuce plants were quantified. In Step 2, the proposal of nutrient transfer management was validated through two treatments, T1 - with nutrient renewal and without nutrient solution renewal during the crop cycle and T2 - with nutrient liquidation and nutrient solution renewal. The experimental design was in randomized blocks. The results were discovered by an analysis of variance followed by the Tukey test at 5% probability. The results collected in Step 1, the production of nutrients for Step 2 was defined. The crop presents satisfactory development, showing that liquidating nutrients offer the reuse of disposal nutrient solutions for the hydroponic lettuce cultivation, thus avoiding the degradation renewal nutrient solution, adapting to sustainable food production.