Growing leafy vegetables in coconut fibre substrates in hydroponic systems under a range of saline water with the use of two innovative electric devices (MaxGrow + Nanobubbles)

Abstract

Hydroponic cultivation systems represent a sustainable and efficient way of growing high-quality leafy vegetables, optimizing all resource inputs and overcoming limitations of traditional soil-based agriculture systems. In the present study, the use of coconut fibre substrates under differing saline irrigation water levels is investigated in hydroponic systems. The potential use of two new technologies: NanoBubbles (NB) and electric MaxGrow stimulation devices, are also evaluated under crop-induced stress to improve crop growth and efficiency. An experimental trial consisting of five treatment electrical conductivity (EC) levels in the nutrient solution (1, 4, 8, 10, and 12 dS/m) was conducted. All treatments were created with normal as well as NB treatment applied. The overall results indicate that at a low EC of 1 dS/m, both growth and biomass increased very well with treatment. However, median biomass from NB treatment resulted in up to 18% improved median biomass results due to moderate levels of salinity under treatment, which is notably higher than that of the control units without NB treatment. The overall results obtained by using NBs for root zone oxygenation, crops improved their tolerance to saline conditions, increasing nutrient absorption, and helped encourage sustainable hydroponic production in areas where access to quality water was limited. Our study provides useful information for future studies aimed at maximizing substrate selection, salinity management, and advanced technological applications.