We are far removed from the days where agriculture and the food system can be rationally separated from the subject of freshwater management. The overwhelming majority of global freshwater withdrawals are consumed for agri-food purposes, and irrigation is responsible for over 40 percent of the food we eat.i Irrigated farmland is vital to the economic prosperity of the global sector, producing higher value and more nutritious crops on average, which are benefits that cascade to provide food security and the drought-resilience for local agricultural communities.ii Irrigation technologies and their associated users, policies and businesses therefore become a central focus in pursuing the ever-growing need for environmental, economic and social sustainability outcomes in the agri-food sector.
The interdependence of water and food systems At its core, the intersection between water and farmland is often taken for granted for its importance in providing for the nutrition and well-being of a growing population. Water and agri-food systems are remarkably dynamic and interconnected, from the standpoint of inputs in production as well as output effects on the quantity and quality of water resources. Just as water is required to irrigate over half of the value of food crops, it is also a leading cause of land degradation and crop loss. Torrential downpours and flooding are primary reasons for soil erosion, while excessive soil moisture can reduce crop yield and heighten pest risks.iii The consequences, however, of modern farming systems frequently lead to significant issues of pesticide and fertilizer runoff. On the other hand, surface and groundwater stores are a valuable production tool for stabilizing
agricultural yields and enabling crop production in regions that would otherwise be too risky. Achieving necessary nutrient requirements while managing the environmental external impacts of agriculture demands a multi-faceted suite of solutions and a transformation in the way agriculture is conducted.iv While no panacea exists for these issues, investment in water technology and the adoption of context-specific, outcome-driven sustainable farming practices are critical movements leading this transformation.v Significant emphasis is placed on physical water productivity enhancements and geospatial precision software, although discussions are relatively sparse surrounding the equally important technologies enabling progress before the point of water distribution. This article advances the conversation for these technologies. The unsung heroes of agricultural water technology: Monitors, pumps and treatments Irrigation involves far more than pipes and pumps. Modern agricultural technology incorporates an interconnected ecosystem of monitoring and functionality tools which share information and work towards specific performance outcomes. While different geographies have context-specific water issues, a general rule of thumb states that the higher the water use efficiency, the greater the value and cost of the infrastructure and technology. There are many significant tech firms blazing trails in the irrigation space; however, we will focus on three with a slightly different approach. These three firms are shifting the face of water technology on the less appreciated back-end: pumps, valves and water treatment.
AQUA4D is a Swiss water technology firm that has been operating internationally for 17 years. Their system treats water before it is distributed to crops through an innovative process that modifies the physical structure of water particles, improving penetration and efficiency, and optimizing irrigation. The technology is particularly useful in irrigating with hard water, which has high mineral content such as calcium carbonate, zinc, iron and magnesium. The AQUA4D treatment dissolves these minerals that deposit in, clog and depreciate physical irrigation assets. The same process also improves drainage of salts below the rhizosphere, preventing the growing issue of saline root-crystallization.vi “Our technology simultaneously addresses the twin issues of water scarcity and land degradation, by keeping soils moist for longer and leaching salts away,” says CEO Eric Valette. “In doing so, we create shared value for growers and contribute to a new paradigm of regenerative agriculture – doing more with less and sustainably improving soil health.” Growers in over 40 countries have benefited from this treatment, including one of Brazil’s biggest, Agricola Famosa, which saved 7,500 hectares from soil salinity while improving production. Recent developments include installations from Chilean avocado growers and strong adoption in the Californian almond sector.vii As time progresses and water scarcity grows, the price of water is set to increase, leading to greater justification for more growers to purchase and implement such treatment technologies.
AMI Global Technologies AMI provides internet-of-things (IoT) condition monitoring and sensory technology for water distribution pump, motors and variable speed drives. Their technology offers end-to-end connectivity for ag-tech irrigation businesses to control devices and analyze the collected data remotely.
Through many years of experience, CEO Henrik Laursen says he has learned that “the value of water is linked to the price of water – the price of water is often linked to the energy it takes to move the water from point A to point Z (from the well to the field). Monitoring that part of the process is critical and if done right, provides enticing returns on investment and positive CO2 footprints per irrigated acre.”viii AMI is currently working with Crop Production Services in the Snake River Valley of Idaho (U.S.), an area that produces nearly 30 percent of potatoes in the United States. The technology’s IoT monitoring and control software has enabled field managers to analyze and decrease pumped water volumes, thereby reducing the energy and labour costs that comprise the majority of irrigation operating expenditures. Alfa Laval, a publicly traded Swedish industrial firm with a strong food and water division, purchased a 20 percent stake in AMI Global earlier this year. This investment is set to take AMI to new heights in IoT water tech innovation. HPNow Another enticing trend in agricultural water treatment is the inclusion of hydrogen peroxide treatment to optimize water quality before application. Biodegradable and generally conducive to stable environmental outcomes, the inclusion of this method in a water management process has been shown to increase drought tolerance and optimize soil conditions to increase potato yields by one recent study.ix HPNow is a Danish firm that offers distributed, on-site hydrogen peroxide generation and safe-concentration treatment in several use-cases. The company’s technology of direct electrochemical synthesis of hydrogen peroxide was originally developed by the company’s co-founders at the Danish Technical University (DTU). Agricultural irrigation is among the most important segments for the firm.
Their HPGen product can improve fertilizer distribution within water pathways, reduce biofilm build-up in irrigation lines and increase oxygen availability to the root zone. It has been linked to successes in cucumber, berry and soft fruit production so far. Increased soil organic matter levels were also indicated in an initial study by the firm. Developments in this treatment space should be closely watched to see how it may be more widely implemented in global irrigation activities. HPNow’s CEO, Ziv Gottesfeld, identifies the importance of fostering research and development in water and ag tech. “The HPGen product line is a prime example of how academic innovation can be turned into a disruptive market offering, with strong positive economic and environmental impact.”
A bright future for the agricultural water technology value chain As the challenges relating to water in the agri-food system are growing, so too is the importance of innovative agricultural water technologies. This movement is underpinned by advances in remote sensing, geospatial technologies and predictive algorithms. While point of use water distribution systems (such as pivot or drip irrigation) and precision agricultural efficiency systems are widely discussed, other dimensions of the irrigation value chain receive less attention. Agricultural water monitors, pumping systems and treatment mechanisms from the innovative firms such as AQUA4D, AMI Global, and HPNow have shown remarkable promise in improving water efficiency, crop yields and equipment maintenance. These trends are set to reach new heights as IoT technologies improve and innovative water treatment methods such as hydrogen peroxide and electromagnetic application. The future is exciting as more research enables a new age for agricultural water technologies, for both back and front-end functions. ●
i Barbier, E. (2019). The Water Paradox. Book. ii The World Bank Group. (2021). Water in Agriculture. iii Rajanna, Dass & Venkatesh. (2019). Excess Water Stress: Effects on Crop and Soil, and Mitigation Strategies. iv The World Bank Group. (2021). Water in Agriculture. v Nikolaou et al. (2020). Implementing Sustainable Irrigation in Water-Scarce Regions under the Impact of Climate Change. Agronomy. https://doi.org/10.3390/agronomy10081120 vi Hachicha et al. (2018). Effect of electromagnetic treatment of saline water on soil and crops. https://doi.org/10.1016/j.jssas.2016.03.003 vii https://www.freshplaza.com/article/9247232/chilean-avocado-growers-challenged-with-drought/?edition=3 viii Interview. (2021). Henrik Laursen. ix Abd Elhady et al. (2021). Hydrogen Peroxide Supplementation in Irrigation Water Alleviates Drought Stress and Boosts Growth and Productivity of Potato Plants. Journal of Sustainability.
Example of AQUA4D treatment facility in California.
Photo: AQUA4D
AMI Vapor X Technology: sensors, pump and tank in action.
Photo: AMI Global
HPGen I-Series addresses water treatment needs of large-scale agriculture through autonomous, scalable, efficient and safe on-site peroxide generation.
Photo: HPNow
Many farmers rely on traditional rules of thumb, including visual observation, crop calendars, and what the neighbours are doing, to decide when and how much to water. Better data and more advanced technologies exist to help make those decisions, but they
aren’t being leveraged currently to their full potential. Now, a new University of Illinois (U.S.)-led study identifies obstacles and solutions to improve performance and adoption of irrigation decision support tools at the field scale.
“We wanted to offer our perspective on how to achieve field-scale precision irrigation with the most recent and advanced technologies on data collection, plant water stress, modelling and decision-making,” says Jingwen Zhang, postdoctoral researcher in the Department of Natural Resources and Environmental Sciences (NRES) at Illinois and lead author on the article in Environmental Research Letters. Some fields are equipped with soil moisture sensors or cameras that detect changes in crop appearance, but there aren’t often enough of them to provide accurate information across fields. Satellites can monitor vegetation from space, but the spatial and temporal resolution of satellite images is often too large to help make decisions at the field scale. Kaiyu Guan, assistant professor in NRES, Blue Waters professor with the National Center for Supercomputing Applications, and project leader on the study, pioneered a way to fuse high-resolution and high-frequency satellite data into one integrated high spatial-temporal resolution product to help track soil and plant conditions. “Based on remote sensing fusion technology and advanced modelling, we can help farmers get a fully scalable solution remotely,” he says. “That's powerful. It can potentially be a revolutionary technology for farmers, not only in the U.S., but also smallholder farmers in developing countries.” With modern satellite technology and Guan’s fusion model, data acquisition won’t be a limiting factor in future precision irrigation products. But it’s still important to define plant water stress appropriately. Historically, irrigation decisions were based solely on measures of soil moisture. Guan’s group recently called for the agricultural industry to redefine drought, not based on soil moisture alone, but on its interaction with atmospheric dryness. “If we consider the soil-plant-atmosphere-continuum as a system, which reflects both soil water supply and atmospheric water demand, we can use those plant-centric metrics to define plant water stress to trigger irrigation,” Zhang says. “Again, if we use our data fusion methods and process-based modelling, we can achieve precision irrigation with very high accuracy and also high resolution.”
The researchers also looked at challenges regarding farmer adoption of existing decision support tools. Because current products are based on less-than-ideal data sources, Guan says producers are reluctant to switch from traditional rule-of-thumb methods to tools that may not be much more reliable. Non-intuitive user interfaces, data privacy and inflexible timing compound the problem. Trenton Franz, associate professor at the University of Nebraska-Lincoln (UNL) and a coauthor, says farmers will be more likely to adopt precision irrigation decision tools if they are accurate down to the field scale, flexible and easy to use. His and Guan’s teams are working on technologies to fill this need and are actively testing the technology in irrigated fields in Nebraska. This includes participating with Daran Rudnick, assistant professor at UNL and co-author of the study, in the UNL Testing Ag Performance (TAPS) program, which focuses on technology adoption and education for producers across the region. “We're pretty close. We have real-time evapotranspiration data, and we’re adding the soil moisture component and the irrigation component. Probably in less than a year this will be launched as a prototype and can be tested among the farmer community,” Guan says.●
A new University of Illinois-led study identifies obstacles and solutions to improve performance and adoption of irrigation decision support tools at the field scale.
Photo: University of Illinois
Some fields are equipped with soil moisture sensors or cameras that detect changes in crop appearance, but there aren’t often enough of them to provide accurate information across fields.
A team of researchers from the National University of Singapore (NUS) has recently developed a solution to address two of the world’s biggest problems – water scarcity and food shortage. They created a solar-powered, fully automated device called SmartFarm that is equipped with a moisture-attracting material to absorb air moisture at night when the relative humidity is higher, and releases water when exposed to sunlight in the day for irrigation. SmartFarm has another advantage – the water harvesting and irrigation process can be fine-tuned to suit different types of plants and local climate for optimal cultivation. The hygroscopic material that is used in the SmartFarm was earlier tested by Hawai’i Space Exploration Analog and Simulation (HI-SEAS) for its application for humidity control for space-based agriculture. “Atmospheric humidity is a huge source of fresh water, but it has remained relatively unexplored. In this work, we’ve tried to mitigate food and water shortage simultaneously. We created a hygroscopic copper-based material and used it to draw moisture from the air. We then integrate this material into a fully automated solar-driven device that utilizes the harvested water to irrigate plants daily without manual intervention,” explained project leader Tan Swee Ching, assistant professor with the Department of Materials Science and Engineering at NUS. The key component of the SmartFarm device is a specially designed copper-based hydrogel, which was produced using an
economical and time-saving process. The material is extremely absorbent, and takes in moisture up to three times its weight. After acquiring moisture, the hydrogel changes colour from brown to dark green and finally to light green when it is saturated with moisture. It also releases water quickly under natural sunlight – one gram of the copper-based hydrogel releases 2.24 gram of water per hour. The NUS team also tested the quality of the water that was collected using the copper-based hydrogel and found that it meets the WHO’s standards for drinking water. Hence, the water collected by the copper-based hydrogel is suitable for drinking and agricultural purposes. The SmartFarm device consists of a container with a movable top cover; copper-based hydrogel placed in a flat rectangular tray; a timer to control the opening and closing of the top cover; solar panels to harness solar energy to power the mechanical work of the device; a control panel system to operate the device, including the open and closing of the top cover of the device; motors and tracks for opening and closing the top cover during irrigation; and acrylic wipers. At night, the top cover opens to allow the copper-based hydrogel to attract atmospheric moisture. In the day, at a pre-set timing, the top cover closes to confine the water vapour, allowing it to be condensed on the enclosure’s surface, particularly on the top cover. Water droplets are gradually formed and when the moisture stored in the copper-based hydrogel is completely released, the top cover automatically opens and water droplets, which are wiped off by the parallel wipers, fall onto the soil to irrigate the plants. The remaining water droplets on the walls of the device continue to provide a humid environment for healthy plant growth. As a proof-of-concept, the NUS team successfully cultivated Ipomoea aquatica (kangkong, a popular vegetable in Southeast Asia) using the SmartFarm device. “The SmartFarm concept greatly reduces the demand for fresh water for irrigation and is suitable for urban farming techniques such as large-scale rooftop farming,” noted Tan. “This is a significant step forward in alleviating water and food scarcity in the near future.” The team has forged a collaboration with HI-SEAS to experiment the application of the hydrogel for humidity control in extra-terrestrial plant growth chambers. “We also hope to explore other potential space applications,” added Tan. HI-SEAS is a remote facility located on the lava fields of Hawaii’s Mauna Loa volcano that is designed to simulate long duration missions to the Moon and Mars. Benjamin Greaves, who joined the Selene II simulated Moon mission at HI-SEAS which took place from November to December 2020, used the hydrogel developed by the NUS team to control the humidity in small experimental greenhouses to grow and sustain crops of edible microgreen sunflower plants and upland cress for the mission astronauts.
“These are perfect for space exploration, because we have a very limited amount of space to grow plants up there, but these microgreens are still packed with nutrients, vitamins and minerals,” said Greaves.
The HI-SEAS experiments showed that the hydrogels developed at NUS offer a potential low cost, low weight and low energy solution to growing crops in self-sustaining farms. The NUS team envisage that the SmartFarm device can be further enhanced with additional functionalities before it moves to large-scale and commercial production. For example, a multi-tiered structure could be designed to maximize the utility of rooftop spaces to increase food production, and an air-cooled condenser could be added to the device if the plants are susceptible to temperature.
Furthermore, to guard against prolonged cloudy days, a heating system could be embedded in the container of copper-based hydrogel to provide sufficient thermal energy to activate the water releasing process without sunlight. In addition, the SmartFarm device can incorporate wireless networking capability to enable users to monitor and control the cultivation process using smartphones. The NUS team is in discussion with commercial partners to explore commercialization opportunities. ●
SmartFarm was developed by researchers from the NUS Department of Materials Science and Engineering: (left to right) Asst Prof Tan Swee Ching, Mr Qu Hao, Ms Yang Jiachen and Dr Zhang Xueping.
Photo: National University of Singapore
SmartFarm is a solar-powered, fully automated device that uses an advanced hydrogel to harvest air moisture for autonomous, self-sustaining urban farming.
Periods of drought are becoming more common in the state of Georgia, U.S., which can have a detrimental effect on the state’s renowned peach industry. Indeed, peach orchards are a common sight throughout middle and south Georgia — helping the “Peach State” live up to its name — and peach producers need more than just the title to ensure both long-established groves and newly planted fields are successful. Traditionally, irrigation management relied solely on rainfall, which is not always predictable. Peach trees are fast-growing, and without rain they will be under stress, which can affect growth, fruit production and fruit quality. So, Dario Chavez, associate professor of horticulture in the Department of Horticulture on the University of Georgia (UGA) Griffin campus, and his research team are working on improving irrigation and fertilization management practices for young peach trees in the Southeastern U.S. Chavez and his team began looking into irrigation versus the industry standard of no irrigation from the time of orchard establishment. The researchers studied two main types of irrigation delivery systems used in fruit production — micro-sprinklers and drip irrigation. Using a supplementary irrigation system from the time of establishment proved beneficial for tree growth,
yield and plant-nutrient uptake compared with trees grown without supplemental irrigation. Drip irrigation was found to be more efficient than sprinkler irrigation. “Plants are like babies — early growth and care serves them for many years to come,” said Chavez. “We looked at the difference it makes for starting with a new method compared to traditional methods. We found good results in production and yield, plant growth parameters and nutritional uptake. There are myriad differences across parameters between the two.” Because Chavez and his team began the research project during a severe drought in 2016, it was easy to visually pick out the drought-stricken trees versus the irrigated trees. The team recommends growers begin irrigating as early as possible, as it benefits the entire orchard. Chavez noted that because periods of drought are becoming more common in Georgia, and not only happening every few years as they did in the past, he recommends growers have a system in place to supplement watering as needed. Water is not the only factor when it comes to the early success of establishing new peach trees. Fertilization is also required to give trees a boost in survival. Because fertilizer is one of the higher costs of running an orchard, knowing the exact amount to use can help a grower keep overall costs down. For this portion of the project, Chavez’s team used different ages of fertilizer based on the recommended rate — 200 percent, 100 percent, 50 percent and 25 percent — over several years to see the impact it had on the nutrients available in the soil, plant and fruit. Their overall goal was to estimate how trees responded to different rates of fertilization.
Research showed that the nutrient concentration, especially nitrogen, for all plant parts (leaves, stems and fruit) did not change significantly based on the amount of fertilizer used. “Once the plant fulfills the amount of nutrients it needs, it stops taking them in,” said Chavez, adding he recommends growers use half of the previously recommended amount of fertilizer and monitoring plant nutrients yearly to help growers to be more cost-effective. He noted that a 50 percent savings in fertilizer can make a big difference for growers trying to keep orchard operating costs down. Currently, Chavez and his team are working on long-term studies in the same areas to estimate whether an overall reduction of 50 percent in fertilizer will affect the orchard growth and production in the long term compared with standard fertilization. They are also collaborating with Professor George Vellidis at the UGA Tifton campus to design a peach irrigation app, which Chavez hopes to make available to growers by the end of this year. ●
Chavez shows off the drip irrigation system used to study irrigation and fertilization management for young peach trees.
Photo: University of Georgia
Covering the 4,000 miles of California’s water canals could save billions of gallons of water and generate renewable power for the state every year, according to a new study. The study was published in the journal Nature Sustainability. Professors Roger Bales, Joshua Viers and Tapan Pathak authored the paper with researchers Andrew Zumkehr, Jenny Ta and Elliot Campbell in collaboration with UC Water and Professor Brandi McKuin of UC Santa Cruz, an alumna of UC Merced.
The research explores the interconnected nature and costs of moving water across the state. It tested the thesis that by erecting a modular system of solar shading panels over California’s exposed aqueducts, the state can reduce evaporative water loss and provide a variety of benefits when compared to conventional ground-mounted solar systems. The Solar AquaGrid study was underwritten by NRG Energy, with development support from the Bay Area agency Citizen Group. Results show a savings of 63 billion gallons of water annually, which is comparable to the amount needed to irrigate 50,000 acres of farmland or meet the residential water needs of more than two million people. And the 13 gigawatts of solar power the solar panels would generate each year would equal about one sixth of the state’s current installed capacity — roughly half the projected new capacity needed by 2030 to meet the state’s decarbonization goals. “The SolarAqua Grid model provides a combined, integrated response to
addressing our water/energy nexus,” Bales said. “It can help address California’s underlying vulnerabilities while meeting both state and federal level commitments to produce renewable energy, lower greenhouse gas emissions and mitigate climate change. Solutions such as these are not only viable but more urgently needed than ever before, particularly as the region returns to what many researchers refer to as a paleo-drought — a worst-case scenario for water managers.” Added UC Santa Cruz postdoctoral scholar Brandi McKuin, lead author of the report: “We were surprised by the significant evaporation savings, which we project to be as much as 82 percent. That amount of water can make a significant difference in water-short regions.” Because the solar panels shade the canals from direct sunlight, they would not only mitigate evaporation but also curtail the growth of aquatic weeds and reduce maintenance costs, while the evaporation that does occur actually cools the panels, increasing their efficiency in converting sunlight to electricity. The analysis shows that adding solar coverings above canals that run across “already disturbed land” means developers can avoid protracted environmental permitting and right-of-way issues so systems can be deployed more quickly and cost effectively. The study estimates that, for California, the resulting annual savings in maintenance costs could be as much as US$40,000 per mile of canal. In addition, the retirement of old diesel pumps and generators in favour of solar arrays would contribute to cleaner air in California’s Central Valley, which suffers from among the worst air quality in the nation.
“What is most compelling about this study is that when you tally up the multiple benefits, solar over canals represents the sort of shift in thinking that California and the world need as we transition our economy and infrastructure to a fossil-free, sustainable future,” said Bales. ●
Covering California's canals in solar panels could save 63 billion gallons of water annually, which is comparable to the amount needed to irrigate 50,000 acres of farmland.
Photo: UC Merced
