In school, we are taught that plants grow in soil. If we go outside of cities into the rural areas of the country, we see traditional farmer’s fields, where the plants shoot up from the ground towards the sun with their roots firmly in the soil. Most people keep potted plants in their houses and parents show their young children how to plant gardens.
Perhaps that’s why the concept of growing plants without soil seems so revolutionary – because we rarely come across it in our daily lives. Indeed, soil does give plants all of the nutrients and water they need, while allowing them to stay anchored in one place. But the truth is that plants don’t really need soil to grow at all.
Hydroponics is one way of growing plants without soil, and as the name suggests it involves water. The basis is that you can meet all of a plants requirements for growth, i.e. stabilizing them, providing nutrients, and a source of water, without having to use soil.
In most hydroponic systems, mineral nutrient solution serves as a plant’s “diet” and source of water. Plants are stabilized in containers with gravel, small rocks, expanded clay, or other mediums. So the plants are able to get everything they need without the use of soil.
Compared to traditional agriculture, there are quite a few advantages to this method of growing plants without soil. Firstly, less water is used because water is not lost to ground runoff and water can be reused. Thanks to the mineral nutrient solution, it’s possible to completely control the plants’ diets. Hydroponics systems take up significantly less space and are therefore easier to harvest. Finally, plants are less susceptible to external factors such as climate, disease, and pests because it is a controlled system.
Aquaponics takes this idea to the next level by combining a hydroponic system with aquaculture, or fish farming. That way, the fish produce waste which is converted into plant nutrients, and the whole system is self-sufficient. There is no soil required, no plant food required, and water is “filtered” by the plants and recycled within the system.
Surprisingly, growing plants without soil is not a new idea. The idea of hydroponics dates back to ancient times, when the Hanging Gardens of Babylon were one of the early wonders of the world. Later, in the 10th and 11th centuries, the Aztecs created an intricate network of floating gardens very similar to aquaponics. Floating gardens were also documented in China.
In the early 1620s, scientist Francis Bacon researched and wrote a book about growing plants without soil. The book, called Sylva Sylvarum was published after his death in 1627 and spawned further research on the topic.
Fast forward to the late 1930s, and scientists at Berkeley were investigating and perfecting soil-less gardening. It wasn’t until recently that these methods have become popular both commercially and for individuals looking to grow plants at home.