Growing spinach (Spinacia Oleracea L.) in floating disks system under a range of saline water with the use of nanobubbles

Abstract

This investigation concerns the cultivation of spinach (Spinacia oleracea L.) under a floating disk hydroponic system subjected to different salinity levels-whether combined with or without nanobubble technology. Conducted under a controlled greenhouse condition, 48 plastic basins (43L capacity), each with six spinach plants fed with 30 liters nutrient solution, were taken for the experiment. Salinity treatments were imposed by adding sodium chloride (NaCl) to reach different electrical conductivities (EC) from 1,2,4,6.8.10.12.14 dS/m. In a parallel setup of the experiment, nanobubbles oxygenation was applied for understanding how it might impact plant growth under salt stress. Key environmental and plant parameters such as temperature, photosynthetically active radiation (PAR), co2 concentration relative humidity, dissolved oxygen, pH and EC were monitored on a weekly basis. The finishing observations included taking SPAD readings, NDVI, fresh biomass weight, length and fresh root length and weight. The results intend to unravel the role played by nanobubbles in alleviating salinity stress through improved root zone oxygenation, nutrient uptake and water management via the generation of reactive oxygen species. According to initial results, nanobubbles assist plants in tolerating high salinity better, leading to improved growth in hydroponics. This study advocates for nanobubbles as a new sustainable and viable technology for saline agriculture and hydroponic crop production.