Nanobubble Irrigation –innovative water use efficiency

After a career as a professional rugby player, and with a background in agriculture, Leon Power and his wife Lauren Oehme are exploring a new way to make water go further.

The New Plymouth pair are the owners of Nanobubble Agritech, which they founded in 2020.

Nanobubble technology is an invention for transferring gas to water, with the key benefit being the ability to supersaturate water so that it can hold levels of gas up to six times greater than previously attainable. Leon explained, “We use nanobubble technology to add extremely high amounts of oxygen gas to farmers’ irrigation water, and this does two main things: it increases crop yield, and it can increase water use efficiency.”

Leon completed a Bachelor of Agricultural Science at Massey University before pursuing a rugby career which saw him play in New Zealand for Taranaki and in Australia for the Brumbies. When playing in Australia in 2018 Leon was also working part-time with an engineering company selling nanobubble technology for wastewater and hydroponic applications. And then COVID hit. “Unfortunately, the opportunities we had in the pipeline were put on hold.”

In 2019–2020 Leon earned a Masters of Business Administration from BeuthHoschule University of Berlin. He wrote his MBA thesis on the use of nanobubbles in anaerobic digestion.

Leon and Lauren made the move back to New Zealand in 2020 and began the journey of setting up their own business. “We started our business trying to see if we could prove that the benefits of higher yield and better plant/root health that were being seen in hydroponic markets were transferable to large-scale soil based growing.”

In the first year they started at Massey University conducting trials on pasture and apples via a Masters in Horticulture student, funded by Callaghan Innovation. Over the past three years they have completed 17 installations or trial sites in Australia and New Zealand on both horticulture, viticulture, vegetable, pastoral, and cropping systems.

The system can be retrofitted to existing irrigation infrastructure, past your bore or water source, utilising your existing pumping systems, and adding the oxygen to the irrigation water that goes out to the farm or orchard.

“However, it also depends on your existing irrigation sprinkler/emitter system. For example, it works best with drip irrigation or low throw sprinklers, but not with K-line, roto-rainers or hard hose types. This is because when we use sprinklers and the droplets fly through the air, a large proportion of the extremely high amounts of oxygen gas that we are forcing the water to hold is lost to the atmosphere, and so a lot of the benefit goes with it.”

“We’ve had to make several technological advances around efficiency of systems, especially in larger water flows such as irrigation where existing nanobubble technology performs quite poorly. We’ve also had to make cost reductions, because outdoor farming has much lower margins per hectare than indoor hydroponic markets.”

He said the two wet La Niña seasons in Australia and New Zealand have provided challenges. Higher rainfall has resulted in a significantly lower use of irrigation, making it harder to reflect on the results of the addition of nanobubbles.

Even so, they have had some very good results. “The results we’ve had so far are absolutely game changing. As an example, in our first trial retrofitting a section of the pivot on ryegrass at Massey University, we achieved 96 percent more dry matter over a five cut summer irrigation period. However, this was under a controlled setting, keeping all the rainfall off. But we’ve been averaging around the +25–30 percent on pasture onfarm, with rainfall making up nearly half of evapotranspiration, and we’ve conducted over eight pastoral sites now. In orchard systems the results are a lot lower, more like +5–15 percent improvements in yield. But we still think that where we can get a longer irrigation season, and preferably using drip irrigation, there is huge potential and the technology can provide good return on investment.”

“Furthermore, where there are underlying issues around soil compaction and/or poor soil health due to low oxygen environments (such as the presence of phytophthora), nanobubbles can provide a solution to improve the growing environment and plant productivity without the introduction of chemicals.“

Leon said they were pleased to recently receive Sustainable Food and Fibre Futures (SFFF) funding. This helps offset a portion of the costs of getting first on-farm installations out on arable and pastoral farms. It also assists collection/analysis of data around yield, environmental benefits of water use, and nutrient leaching, an area in which he thinks they will be able to see some improvements.

“As a result of this co-contribution, it’s made it easier to get our first pivot on a dairy farm in Ashburton over the later part of this irrigation season, and we hope to get a few more next year.”

We have made huge progress in terms of the technology and manufacturing side – all our systems are made here in New Zealand – as well as crop results. We’ve consistently had increases in yield on pasture over several sites and soil types, as well as some strong results in some orchard installations including apples, oranges and a little on kiwifruit, while others overseas have also reported good results on cherries and avocados.

As with any new technology, Leon said there are challenges to the system. “In arable/ pastoral systems, to get around the long throw sprinkler issue we use our system in conjunction with mobile drip irrigation, which is essentially a whole lot of drip irrigation being towed by a pivot. The benefit is that this keeps the oxygen in the water and it is applied directly to the root zone. It has further benefits of higher water use efficiency due to less wind, plant surface and soil evaporative losses.”

He said some farms were better suited for this system than others. On farms with stock, grazing management/paddock selection must be used to keep stock from being in the paddock at the same time as the pivots. “This is our biggest challenge regarding using it on a dairy farm where the cows are walking back and forth to the cowshed on races that pivots are passing over. We’re currently targeting those with ring raced systems or races on the outside of pivots. But ultimately, with the increase in production we’re hoping to find ways to get around this.”

As for the cost, Leon noted that as with any irrigation infrastructure there was a cost. “We are offering the option of long-term leasing, which will hopefully increase uptake and de-risk the technology for farmers. This is especially useful while we are still learning what true benefits we can expect to see on-farm. This will take multiple seasons and many installations over a variety of regions and farming systems, as no two operations are ever the same.”

He said some of their biggest achievements had been not only the trial results but also the advancements with manufacturing. “We have made huge progress in terms of the technology and manufacturing side – all our systems are made here in New Zealand – as well as crop results. We’ve consistently had increases in yield on pasture over several sites and soil types, as well as some strong results in some orchard installations including apples, oranges and a little on kiwifruit, while others overseas have also reported good results on cherries and avocados.”

He said they were still working on improving the way the technology works, as well as developing the understanding on why they get better response in some crops or set-ups than others.

“A return to dryer El Niño summers with more irrigation use would be helpful for us, as most of our orchard trial sites haven’t had the opportunity to get much irrigation or data back over the last two seasons.”

Nanobubble Agritech currently have drop in, retrofittable systems, and would like to enlarge their reliable history of installation data This would enable farmers and growers to see that putting in a Nanobubble Agritech system is going to get them roughly X more production or benefit per ha, at X cost per year, equating to X more income.

“Ultimately, we’d like to see every irrigator in the world incorporating our technology. The environmental and productivity impact that this more efficient use of water would have on the world’s resources would be unbelievable.”

We want the same as everyone that is trying to bring through new technology in farming – to provide a tool that enables farmers to grow more efficiently, with less negative environmental impact. If we can do this it brings down the cost of food, and hopefully leads to a happier, healthier population.