Plants can grow without soil.
The earliest historical records show a hydroponic like cultivation in MExico during period 1150 – 1350 CE.
Morehart, C. (2016). CHINAMPA AGRICULTURE, SURPLUS PRODUCTION, AND POLITICAL CHANGE AT XALTOCAN, MEXICO. Ancient Mesoamerica, 27 (1), 183-196. doi:10.1017/S0956536116000109
More recently V.M.Artsikhovski published in the journal “Experienced Agronomy” an article “On Air Plant Cultures”, in 1911, about his method of physiological studies of root systems by spraying various substances in the surrounding air - the aeroponics method. He designed the first practical aeroponics system.
Soil less plant growth is of much interest for cultivation in space, where every resource transportation involves exorbitant cost.
Soiless plant growth are generally classified as hydroponic, aquaponic and aeroponic.
Hydroponics involves immersion of the rhizosphere in a nutrient rich water solution.
Aquaponics is hydroponics with nutriente being generated by marine life, usually fish, but also arthropods.
Aeroponics uses a spray of nutrient rich water droplets between 5 and 50um directly on to the plant roots.
The advantages of soiless growth include very low waste of water and fertilizer, prevention of soil based infection, increased growth area in vertical systems, cultivation in resource constrained areas, ability to increase photosynthesis by artifical lighting.
Disadvantages are extreme dependency on un interrupted power, plant death if humidity levels are not mainatined for periods as low as 20 minutes, external nutrient supply and the need for good electronic control systems.
An aeroponic system can be setup in a lab for highily controlled plant growth experiments and growing of exotic species.
There are multiple variations on the above methods.
WE will construct two types
We will use commonly available materials. The goal is to encourage urban farming and experiments, at low cost.
Here is a photo of first prototype: