Aeroponics:
See Fig 5.4. Aeroponic systems employ no media. The plant’s root system is
freely suspended in a tank. The nutrient is delivered as a fine mist (or
fog) via the use of spray jets and a high pressure pump, which typically
operates 24 hours per day.
Advantages:
+
Ideal for ensuring roots have an oxygen rich environment. However to
achieve this, the air inside the nutrient reservoir must be ventilated to
prevent oxygen depletion.
+
Avoids the supply, disposal and cost problems associated with medium based
systems.
+
Easy to sterilize roots and hardware.
+
Permits routine inspections of roots for signs of disease and feed
adequacy, etc.
+ The
absence of a medium prevents local salt build-up in a dense root zone.
+
Root zone EC and pH will be in equilibrium with that of the nutrient
solution.
Disadvantages:
+
Pump failure can result in plant death within a few hours, especially in
hot weather.
+
Spray jets are prone to blockages therefore filters and routine
maintenance of the feed circuit are most necessary.
+
Evaporation losses are high and, accordingly, salt buildup in the nutrient
can be rapid unless more frequent dumping is performed.
