Assessment of the development of Lactuca sativa Batavia Aficion in hydroponic and aquaponic systems

Abstract

The need to improve the methods of growing plants in hydroponic systems to ensure optimal conditions for their growth and achieve high yields is urgent. The purpose of this study was to compare the hydroponic production of Lactuca sativa Batavia Aficion using a conventional Knop nutrient solution compared to aquaponics using nutrient-rich fish water. Laboratory, potentiometric, and photometric methods were used for this purpose. The yield, biometric, and qualitative indicators of lettuce leaves were investigated. Despite the lower nutrient concentration in the aquaponic solution, the nutritional status of Lactuca sativa Batavia Aficion was within the optimal range. The nitrate content of lettuce grown in the aquaponics system was higher than in hydroponics, but there were no significant differences in the content of total N (3.24% and 2.97%), Mg (1,973 mg/kg and 1,943 mg/kg), Fe (93.91 mg/kg and 93.83 mg/kg), K (73.7 mg/kg and 73.6 mg/kg), and Ca (19.5 mg/kg and 20.1 mg/kg). The yield of Lactuca sativa Batavia Aficion on aquaponics was 2.8 kg / m2 and 3.2 kg m2 – on hydroponics, with a density of 36 plants per square metre. Water monitoring in the aquaponic system showed low concentrations of nitrates, phosphorus (P), potassium (K), and magnesium (Mg), but the proportion of mineral nutrients and pH were stable throughout the lettuce growing period. Lettuce leaves in the aquaponics system reached a fresh weight of 80 g in 34 days, which is on average 13% less than lettuce leaves in the hydroponics system. The EC (electrical conductivity) values recorded in this study in a hydroponic system were between 1.2 and 1.5 cm/m. In the aquaponic system, EC has higher values due to the low rate of water replacement, contributing to greater growth and accumulation of solution ions. However, due to continuous recirculation in the water, the conditions become satisfactory for growing plants. The results obtained can contribute to the creation of more efficient and sustainable agricultural systems, reducing resource consumption and improving the resistance of cultivated crops to various stressful conditions