Especially in the drought-ridden west, water conservation is a topic of increasing concern. You've recently heard about water in the news, across social media, and among friends - not just from farmers. Drought conditions and lack of water impacts agriculturalists, municipalities, industries, and individuals.So how can hydroponic and aquaponic systems reduce water loss, increase water use efficiency, and use water more sustainably?
Typical water loss in aquaponics and hydroponics
In most hydroponic farming systems, water is recirculated. Run-off water that is not taken up by the plants is recaptured. Nutrients are constantly added by fish waste or fertilizer, and water returns to the plants. Every bit of water is reused over and over again, an impossibility in traditional, soil-based agriculture.
Since it is recirculated and recycled, water is never discharged in hydroponics or aquaponics. Water loss occurs in two main ways:
Evapo-transpiration is the use and evaporation of water through the plants. There is no way to eliminate evapo-transpiration; it is a necessary function of living plants! You can, however, keep it as efficient as biologically possible by making sure that your temperature range is suitable for the crops you are growing.
Leaks sometimes form in the greenhouse irrigation system. This might be a broken pipe or split tubing, but it's most likely that a dripper has been displaced or a leaf is redirecting the water flow. Careful and frequent monitoring of the system is the best way to identify leaks. We walk through our green house three times a day to check for leaks, then make repairs as quickly as possible.
Water loss in traditional systems
Traditional gardening requires 20 times the water use of a recirculating system. Why is that? Agricultural flood irrigation in large fields loses water to simple evaporation, run-off, and dispersion beyond the reach of plant roots. The agricultural industry is changing its practices to be more water-wise, but even the best drip irrigation only cuts flood irrigation losses by about one-fourth, nothing close to hydroponics.