Nowadays it is impossible to deny that we have a water management problem. Global resource scarcity compels governments and companies to look for new solutions to address the water crisis. The Mediterranean climate in most of Spain, featuring scant and uneven precipitation, results in excess pressures on water resources, and impacts on natural ecosystems.
The available global volume of renewable freshwater is about 7,000 m3 per person per day, and agriculture by itself consumes between 60% and 70% of the available water resources. According to the UNESCO, by 2050 that per cent could increase by up to 19% if the world's population continues to grow and we do not find ways to improve water management.
In this scenario, it is more urgent than ever to modernise irrigation to allow the sustainable use of available water resources, without putting our environment at risk.
Spain can be proud to lead the way in this area, as a world leader in agricultural water efficiency, in particular in the use of localised irrigation systems. The data speak for themselves: the total irrigated area in Spain last year amounted to 3,774,286 ha, an 1.08% increase from 2017, while agricultural water use decreased by 25% thanks to the modernisation of irrigation systems.
New technologies and the much needed shift to sustainable agricultural management brought about irrigation modernisation policies, investments in upgrades to water withdrawal, conveyance and delivery infrastructure, and innovation in irrigation systems.
New research projects in this field have focused exactly on that: driven by new technologies, they try to increase the energy efficiency of water treatment processes, turn to digital tools farmers can use, and rely on research as a driver of sustainability.
Spain can be proud to lead the way in this area, as a world leader in agricultural water efficiency
A solvent to desalinate water
The severe drought in the south-east of Spain has led to a significant increase in the demand of desalinated water for irrigation.
Given that 97.5% of the water in the world is salt water, desalination is an important water source to consider for irrigation. Water resources are limited and the use of desalinated water does not put at risk these resources, while it provides certainty about the supply.
Spain is one of the largest producers of desalinated water in the world, with a capacity of some 5,000,000 m3 per day, and 765 desalination plants that supply water for drinking, irrigation, and industrial uses. However, the brine resulting from RO desalination processes in these water treatment plants is an increasing environmental concern.
Committed to environmental protection, and concerned about the sustainability of a technique which is very much needed to obtain water for irrigation, researchers from Columbia University tried to desalinate water through the use of a solvent and changing the temperature. They concluded that the Temperature Swing Solvent Extraction (TSSE) technique can be used to treat brine without the pressures that would be needed to use RO, and solvent extraction is a useful separation method widely employed for chemical engineering processes.
The advantage of this method is that it requires few resources, it is relatively inexpensive and simple in comparison with similar treatment processes, and could mean a significant improvement to make use of available resources for agriculture.
Plants response to drought, from space
Understanding how plants respond to water stress to reduce the vulnerability of crops during periods of water shortage may be possible thanks to ECOSTRESS, and international project aimed to compile data on how plants all over the world manage water.
The initiative uses International Space Station communications to compile data and send them to scientists. The instruments used measure ground temperatures and the temperature of plants as they heat up when they run out of water. This way, we can know which plants are suffering water stress and when they need water. In addition, researchers can estimate the amount of water that evaporates from the Earth's surface and from plants, and use statistics to enable efficient irrigation management.
Using sludge from waste water treatment plants as fertiliser
CircRural4.0 was born to transform waste water treatment plants located in rural areas into sustainable plants.
Different research centres and institutes take part in the project, supported by Promedio, the environmental services management consortium for the province of Badajoz, in Spain. It includes a proposal that specifically deals with nutrient recovery from treatment plant waste.
The waste generated by these plants, the sludge, has a high value as agricultural fertiliser, so transforming them to become an active part of a circular economy would be a green solution to manage the waste generated by waste water treatment plants.
It is more urgent than ever to modernise irrigation, to allow the sustainable use of available water resources
Drones to detect soil moisture
Australia, one of the countries most affected by drought, has developed an innovative system to detect moisture in irrigated paddocks. Using drones, agricultural land is mapped to detect those areas that need water and apply the right amount of water for each crop.
The sensors in the drones have the capacity to analyse soil moisture at metre-level scales, so farmers can apply just the right amounts of water to avoid wastage.
The project, led by Monash university, could be a real revolution for the agricultural sector, integrating smart technology to manage irrigation in a more efficient and sustainable way.
Irriman: mobile irrigation
Imagine we could plan more sustainable irrigation through a mobile application.
That was researchers' idea behind Irriman Life+, a mobile application that provides, free of charge, information about water availability in an irrigated area and allows daily recording of irrigation data, on the amount of water used, the duration, and the frequency of water application.
The project, coordinated by the Polytechnic University of Cartagena, and in collaboration with the Department of Agriculture, Water, Livestock and Fishing of the Regional Government of Murcia, in Spain, encourages sustainable irrigation strategies among farmers, so they can make use of available water resources without wasting a drop of water.
Therefore, it is clear that we have solutions based on research and technology to facilitate the job of farmers and mitigate the impact of water stress on our resources. All we need to do is manage irrigation efficiently and rely on technological advances to ease the pressures of water use for food production.