Vertical farming for crop production

Vertical farming is a well‐established method of cultivating high‐value vegetables and fruits. However, the practice of growing staple crops in vertical farms is still a new and evolving issue. Recently, a wheat crop annual yield of 11.7 kg per m ground area was demonstrated in a vertical farming facility (https://www. infarm.com/news/another‐step‐towards‐a‐future‐where‐ food‐insecurity‐is‐a‐thing‐of‐the‐past). Vertical farming involves the cultivation of crops in vertically stacked layers in a highly controlled indoor environment, offering several benefits, including but not limited to higher water and nutrient efficiency, reduced use of pesticides and herbicides and decreased agricultural pollution. To enable large‐scale production of staple crops through vertical farming, efforts must be made to optimise photosynthesis and growth dynamics for increased yields, breed crops that are more efficient for vertical farming and cut down energy costs. Combining vertical farming with photovoltaics‐based electricity generation can help increase the overall light energy use efficiency and represents a potential way forward. Recently, Infarm has announced a breakthrough in vertical farming by successfully producing wheat in an indoor farm and achieving an impressive yield of 11.7 kg per m ground area (https://www.infarm.com/ news/another‐step‐towards‐a‐future‐where‐food‐insecurity‐is‐a‐thing‐of‐the‐past). This projection equates to 117 tons per hectare per year, making a significant milestone in the journey towards growing staple crops for global food security through vertical farming. The concept of vertical farming was first proposed over two decades ago by Prof. Dickson Despommier from Columbia University in the US and by Prof. Toyoki Kozai from Chiba University in Japan. It involves growing crops in vertically stacked layers in a highly controlled environment, leveraging modern technologies such as sensors, artificial intelligence and robotics etc. Vertical farming offers potential solutions to several critical challenges in modern agriculture, including land scarcity, water conservation, climate control and food security. It has often been proposed as an approach to meet the projected 70% increase in food demand by 2050. According to the Food and Agriculture Organization of United Nations, the world's arable land area has decreased by 33% since 1961, and was approximately 1.38 billion hectares in 2019 (https://worldpopulationreview.com/ country‐rankings/arable‐land‐by‐country). The average annual increase in crop yield per unit area, at about 1.5% since 1961, is insufficient to meet this rising demand for food production. By growing crops on multiple stacked layers and maximising yield per plant growing area, vertical farming holds the promise of dramatically increasing food production. For example, for wheat production, the yield in vertical farming theoretically can be as high as 220–600 times of that achieved in conventional farm land. In addition to expanding planting/growing areas, vertical farming also offers numerous additional benefits. By growing crops indoors, it protects crop production from environmental and weather disruption, while optimising environmental parameters, such as light, temperature, humidity and CO2 levels. Vertical farming also boasts water use efficiency through the reuse of drained water and recapturing of transpired water as well as improved nutrient efficiency and reduced agricultural pollution and greenhouse gas emissions. With crops grown in isolation from the outside environment, the utilisation of chemicals such as pesticides and herbicides can be reduced, offering