Access to water, its quantity and quality, is probably the greatest challenge facing agriculture in today's world. In addition to the problems arising from climate change, we have to add the enormous consumption of a world population that is now approaching 8 billion people. And, not least, the deterioration of aquifers due to the incorporation of irrigation waste laden with fertilisers or phytosanitary products. The consequence of this is an exceptional load of salts in the water. This load means that the nutrients that we need to incorporate into our plants cannot be absorbed in the quantities required. Osmosis is the solution to this problem.
The parameter we use to measure this data is called the Electrical Conductivity (EC) of water. This is the capacity of water to conduct an electric current. And it is through this data that we can estimate the amount of salts present in the water or the substrate. In the area where we have installed our greenhouses (Humilladero, Malaga) we have water with a high conductivity parameter. It is normal to obtain measurements above 3.0 EC-ms. Although this figure is reasonable for many of the crops in the area, it is not reasonable for pitaya.
Our aim is to achieve irrigation water close to 0 EC and for this the solution is osmosis. That is why we have set up a reverse osmosis system that we apply to the water before it enters the irrigation circuit.
These are the cisterns that contain the water we use to feed our recirculating hydroponic system. One of them contains the water as we draw it from the farm's service well (EC > 3) and the other after being osmotised (EC< 1). It is from this second cistern that we take the water for irrigation.
As our greenhouses are recirculating hydroponic greenhouses, water consumption is minimal, as water is reused after each watering cycle. This is why the osmotisation plant we have installed is not excessively powerful. It provides us with 1,000 litres per hour, which is more than enough for our needs.
The equipment necessary to carry out the osmosis process. Catalysed zeolite filter, microfiltration cartridges, additive addition system, high pressure pump and membranes.
The installation of our osmosis equipment, from the company Green Biozone is a further step in the process of trying to obtain the highest quality fruit.