More people now live in cities rather than in rural locations. Feeding cities presents a considerable and increasing challenge. Land is increasingly precious as population numbers increase and the area of arable land available for crop production declines. Can we be more imaginative about the use of space and growing methods to increase the production of fresh food?
Alternative methods of growing seek to increase food supply while repairing current environmental damage and addressing biodiversity, climate change and impending water and energy shortages. Alternative methods of growing food include vertical gardens, permaculture, hydroponics and LED grow lights. These are certainly not the only methods being explored today.
Vertical gardens or green walls change the traditional horizontal growing surface of the land to a vertical one by creating a specially designed supporting structure that enables plants to grow up a wall. Vertical gardens can vary from baskets, plastic water bottles or growing sacks hanging on a wall to a much more complicated system to provide soil or some other medium for the plants.
Permaculture can help farmers produce more food using fewer resources through agroecology, a farming approach that mimics natural ecosystems. In practice, permaculture farms are organic, low input, and biodiverse, and use techniques like intercropping trees, planting perennials, water harvesting, and resource recycling.
Hydroponics is a growing system that replaces soil with mineral nutrient solutions dissolved in water as the growing medium. The plant’s roots are suspended in this liquid solution. Hydroponic methods are often used in rooftop gardens.
LED Grow Lights use less electricity than traditional sources. The light can be split into wavelengths most useful for growth and development of the crops. Plants mainly need blue and red light for photosynthesis, and the special LED lights can provide the exact colours that the plant needs.
Each of these growing methods has many variations and off shoots, for example, aquaponics combines aquatic animals (fish, snails, crayfish) with hydroponics; agroforestry is based on permaculture principles combining trees with crops in rows and/or livestock; and vertical farms grow plants vertically in layers in a multi-story greenhouse.