Hydroponics is the growth of plants in a liquid medium, rather than soil. Plants are often supported at the stalk, leaving the roots free floating. In other cases, roots may be supported by inorganic media, such as plastic pellets, gravel, or mineral wool. All nutrients are supplied through the liquid.
The liquid is held by vessels or pipes, that in some cases include a circulation system with automatic renewal and filtering. All parts that are in regular contact with the liquid are cleaned or replaced in regular intervals.
This method provides several advantages to a colony on Mars:
- Disease Control
- Increased Crop Yield
While a natural soil based environment can stabilize itself, the hydroponics require technological support and regular maintenance:
- Artificial fertilizer and other auxiliary substances (antibiotics, cleaners, acidity regulators, etc. ) needed, which requires a chemical industry behind.
- Cleaning and disposal of toxic degradation products.
- Higher manual maintenance effort.
- How much can the crop yield increase (per worker, per m2, per light energy)?
- What fertilizers can be used?
- What other auxiliary substances are needed?