By the middle of the century, the global population is expected to reach nine billion (Wang, Liu and Cheung, 2017). Hence, the increase in global population was expected to stay in urban areas in the future (Soga et al., 2017). Various developments were planned in major cities to meet the population density. This reduces the amount of space available in the urban area. As mentioned by (Despommier, 2011), as the popularity of urban populations rising over time, concerns about climate change, urban overheating, environmental quality problems, insecurity food and food supply declines in urban areas are expected to worsen.
Food production will need to be doubled to compensate the parallel increase in demand for food species (Khan, 2018). One way of solving unhealthy or inadequate food access in cities is increasingly considered urban farming (Ackerman et al., 2014).
In recent years, urban farming has become more prominent to promote local food production and distribution, provide urban green space and improve access to healthy food (Poulsen et al.
, 2014). Urban farming is defined by (Hendrickson & Porth, 2012) as a localized food system in which food and other products are grown, processed, distributed, grown in or around the city by plants. Cultural value and quality of life are enhanced by farming through growing vegetation in various urban areas including schools, rooftops, roadsides, apartments, balconies, abandoned buildings and hospitals (Moon, 2012). There are several urban farm types like community or allotment gardens, private gardens, easement gardens, rooftop gardens or green roofs, urban orchards and peri-urban agriculture (Lin, Philpott, Jha, & Liere, 2017).
While, there are three major types of urban farm such as backyard gardens, community gardens, and commercial farms (Hui, 2011). The backyard gardeners use the land around their homes to grow plants like rooftops and balconies. Community gardener is a larger piece of land gardened by several households together. Products from both garden types are mainly used for home usage. Urban commercial farms are designed for profits and can be combined with commercial kitchens to produce food products with added value and are sold on to farmer’s markets and restaurants. Urban farming activities in cities affect the safety of food, health and poverty rates (Hong, 2016).
A comprehensive list of prominent threats in the future for agricultural crops would also include climate change, decline in fishing activities (prompting a higher food burden in products based on land), increasing urbanization, increasing agro-industry costs (e.g. fertilizers, fuel, pesticides), rapid population growth, soil degradation and poorly educated over farming (Benke & Tomkins, 2017). Urban farming may assume a significant role in the sustainability of food systems with regard to prominent threats, food consumption habits and the potential of local producers (Benis & Ferr?o, 2017). A new method to solve the problem of sustainability and the growing demand for food is the design and implementation of vertical farms.
Vertical farming is a concept which includes cultivating livestock plants on vertically inclined surfaces, such as in urban skyscrapers, where land and space lack (Lumpur, 2017). With urban areas growing worldwide, vertical farming methods should be improved to supplement urban food requirements (Game, 2015). The future farming methods in cities be comprised of use of vertical hydroponic farming techniques in backyard gardens, rooftop farm, community garden, greenhouses, balconies and indoor farm. Hydroponic is one farming technique that may be used other than soil-based gardening in vertical urban farming. Hydroponics is a way of cultivating plants in a solution based on water and nutrient. Hydroponics does not use soil, rather it supports the root system with an inert medium such as perlite, rockwool, clay pellets, peat moss, or vermiculite. The fundamental premise for hydroponics is that the roots of the plants have direct contact with the solution of nutrients while accessing oxygen, which is vital to proper growth. Hydroponic systems offer a range of benefits including water and nutrient reuse capability and easy environmental controls as well as the prevention of soils and pests (Lee & Lee, 2015). Moreover, urban residents can generate their own fresh food at home.