Yield of lettuce grown in hydroponic and aquaponic systems using different substrates

Abstract

This study had as objective to evaluate the effect of the substrate on the yield of lettuce grown in aquaponic and hydroponic systems. The study was conducted at the Federal University of Grande Dourados, located in Dourados, MS. A randomized complete block design was used, with three treatments and 16 replicates. The cultivation systems were analyzed independently. The substrates analyzed were: coconut shell fiber, phenolic foam and expanded vermiculite. The plants were grown in two systems (aquaponic and hydroponic), using the NFT (Nutrient Film Technique) system. The crop used was lettuce cv. ‘Alcione’. The parameters analyzed were: crop yield and percentage of roots per plant. In addition, macronutrient contents were analyzed in the leaves. The substrate composed of coconut shell fiber was more suitable for lettuce production, since it led to higher yields for both aquaponic (2.88 kg m^-2) and hydroponic (2.58 kg m^-2) systems. The use of phenolic foam as growing substrate led to lower mean crop yields in both production systems analyzed, 1.94 and 2.15 kg m^-2 for aquaponic and hydroponic systems, respectively.