Urban Farming: Production comparison of Basil and Oak Leaf lettuce in two hydroponic growing systems : an industrial collaborated study in Sweden

Abstract: The modern agriculture of the world is facing huge challenges in terms of increasing scarcity of natural resources such as water and land. The increase in global population is not only enabling in expansion of big cities but also raising questions of accommodating and feeding this amount of population. A global food security risk and pressure on existing natural resources are well expected in coming years. The use of chemicals and fertilizers to increase food production from the same land area is posing serious risks to human health and environment by increasing the emission of greenhouse gases. In this intricate scenario, indoor urban farming is gaining popularity because of many coupled advantages and benefits. Vertical farming is now being considered a means to grow and supply crops to cities. Advanced types of hydroponics and aquaponics are being tested and used to increase the per square meter production of crops. The controlled climate conditions enable the production of crops irrespective of outside weather conditions. The trend of conversion of abandoned buildings, warehouses, basements etc. into indoor food production plant factories is increasingly rapidly. This type of farming also allows for chemical free produce. SweGreen AB is a local Swedish company based in Stockholm with its farm located in the basement of an office building. The company is already in the stage of commercial production of leafy greens. In order to further streamline and strengthen the production processes, company is adopting new and advanced hydroponic based vertical production systems. This study was aimed to investigate the production of basil and oak leaf lettuce in two different types of growing systems i.e. Testbed vertical layer system and zip grow tower system. The vertical layer systems are reported to grow more plants per square meter and more production. The results showed that plants grown in vertical layer test bed system tend to have more plant height, leaf numbers, higher chlorophyll contents and lower leaf temperature than the zip grow system. The energy efficiency is no doubt improved in vertical farming systems but the high costs of energy usage and its effect on environment must be taken into account. The fresh weight of plants grown in test bed system was also higher than the ones grown in zip grow system. Further studies are needed to investigate the crop production potential on commercial scale with precision farming, integration of AI (artificial intelligence) and IOT (internet of things) along with complete control on factors like temperature, humidity, CO2 levels, light and nutrients.