As the world grapples with the water scarcity crisis, attention is increasingly turning to irrigation practices as a major contributor. From rethinking fertilizers to leveraging seawater for cooling, can alternative irrigation strategies help tackle this ever-growing issue?
Here, I share my thoughts on how we can address water scarcity using improved irrigation methods.
Water scarcity: What’s irrigation got to do with it?
When we talk about water consumption and conservation, the conversation often gravitates towards domestic water usage and how we can conserve more water more efficiently. However, domestic household consumption represents a small fraction — around 10% — of global water consumption.
In complete contrast, countries like Saudi Arabia allocate around 85-95% of water consumption for irrigation purposes. So, when we address water scarcity, our attention should shift towards the major consumers of water namely the energy, industrial, and irrigation sectors. In regions like the Middle East, where water scarcity is pronounced, improving irrigation methods is crucial to this challenge.
Rethinking irrigation methods to address sustainability and scarcity
The choice of how we irrigate and how we grow agriculture is incredibly important. Let’s consider the fact that when we use potassium chloride as a fertilizer, residual potassium chloride is left in the soil, which necessitates even more water to be used to flush it out. When we replace potassium chloride with potassium nitrate — which directly benefits agriculture by contributing both potassium and nitrate to the soil — we can also yield significant water savings. While this appears to be a simple swap, it can drastically reduce the amount of water needed for irrigation.
Additionally, when we look at how food is cultivated — whether in open fields, greenhouses, or vertical farms — we identify several important avenues for curbing our water usage.
In open fields, challenges such as evaporation and transpiration significantly increase water demands. Conversely, while greenhouses mitigate evaporation issues, they also require cooling methods, particularly in arid regions like the Middle East. Utilizing brine or seawater for cooling presents a viable alternative to freshwater when it comes to using greenhouses to grow food.
Similarly, in landscaping, optimizing soil composition, fertilizer use, and irrigation methods, whether surface or subsurface, diminishes water requirements.
It’s well known that greening an area (which of course requires the use of water) reduces the temperature of the areas between 1 and 5 degrees, and studies have consistently shown that green environments are significantly cooler than brown or concrete environments. Leveraging freshwater for irrigation contributes positively to both the local environment and the Earth’s atmosphere.
Optimized irrigation methods in practice
In NEOM, we’ve implemented the following innovative strategies to optimize water usage:
- We utilize potassium chloride derived from desalination instead of relying on imported potassium chloride for fertilization.
- We convert the potassium chloride into potassium nitrate so that the fertilizer is more useful for its intended purpose.
- We use seawater to cool greenhouses inside NEOM.
- We repurpose byproducts, by adding the seawater concentration to the brine processing stage.
These sustainable agricultural practices not only enable us to save water within the irrigation process but also allow us to foster a circular economy in terms of water reuse.
Additionally, selecting the appropriate water type is crucial for irrigation success. Desalinated water for irrigation does not need to meet potable standards; water with a total dissolved solids (TDS) level of 500 or 1000 can be used for irrigation without compromising effectiveness. In certain cases, tomatoes have been grown using even saltier water, such as seawater, for irrigation.
Finally, we consider the entire water lifecycle from start to finish rather than focusing solely on individual use cases. This integrated approach, including desalination, brine processing, and water reuse, goes a long way in ensuring efficiency, and sustainability, and reducing water scarcity.
Qatium Experts
Gavin Van Tonder is the Executive Director of Water at NEOM, a new region under development in Saudi Arabia, and was previously the President for Water at Itron. Gavin is one of many experts that we co-create with Qatium.
