Hydroponic tomato (Solanum lycopersicum L.) production with and without recirculation of nutrient solution

The hydroponic systems with recirculation of nutrient solution save water and fertilizer, but over time it is difficult to maintain the nutritional balance and control diseases that attack the roots, causing lower performance compared to systems where the solution is not recirculated. The objective of this study was to compare the water use efficiency and nutrients, as well as the yield in growing tomato (Solanum lycopersicum L.), between open and closed hydroponic systems using a crop management strategy based on short cycles, by the pruning at three clusters per plant. The experimental design was randomized blocks with five replications and five treatments: 1) beds without recirculation of drainage (open bed); 2) beds with recirculation of drainage (closed bed); 3) bags without recirculation of drainage (open bag); 4) bags with recirculation of drains (closed bag), 5) deep hydroponics. With the data an ANOVA was performed and means were compared using the Tukey test (p≤0.05). Morphological traits, yield, water use and fertilizers were measured. The highest yields were obtained with deep hydroponics (16.7 kg m^-2) and with closed bags (15.3 kg m^-2) in a crop cycle of four months. The fertilizer savings (K, Ca, N and P) in recirculation systems with substrate was 41 % and 35 % of water in relation to the systems without recirculation.