Take-home message: Through demonstrations in California’s Central Valley over the past 12 months, AQUA4D® has shown it is the most efficient soil salinity solution currently on the market. Let’s take a look at some insights from recent success stories at almond and pistachio orchards.

In many parts of the Central Valley, as indeed around the world, growers have one common enemy: water and soil with high salt content. This excessive salt crystallizing in the soil over time is problematic for sensitive crops. Among these are almond and pistachio trees, which suffer the consequences with stunted growth, burnt leaves, and ultimately lower yields. Considering the importance of these crops to the region’s economy, any avoidance of loss is hugely beneficial.

Treating water to regenerate soils

Over time, repeated irrigation of crops with saline or brackish water results in a build-up of soil electroconductivity (EC). Recent studies involving AQUA4D® technology have shown an ability to stunningly reduce soil salinity levels, regenerating soils and allowing trees to recover – and thrive.

At a large pistachio orchard in Fresno, for example, the EC went from 7.9 to 0.9 within 2 years, while in a nearby young almond plot, after just 5 months of irrigation the plot treated by AQUA4D® had salinity levels two times lower than the untreated plot. Given the role of excess salt in harming tree development, and increasing salinization worldwide, a solution like this – solving the problem without water-intensive leaching and without chemicals – could be a true game changer.

AQUA4D co-founder Walter K. Thut moved to the Central Valley in 2018.

How exactly does AQUA4D® resolve soil salinity?  Co-Founder Walter K. Thut explains:

“First, we need to understand where this salinity stems from: from irrigation with water containing high quantities of salt. Over time, water (particularly well water and melt water) undergoes certain physical changes which reduce its capacity for transporting salts (minerals). With every irrigation cycle it loses some of these salts in the soil. These salts crystallize and block the upper part of the soil, creating water penetration problems and reducing the capacity of the soil to store and retain water. In the root zone, crystallization of sodium chloride burns the plants. Ultimately this all impacts on health and yields.”

Treatment by AQUA4D gradually dissolves such crystallizations, opening up these finer pores and thus increasing water retention. “We see how saving salt issues and water are inextricably related,” concludes Thut.  “Our technology increases the capacity of the water to transport salts in ionic (dissolved) form, meaning the water does not lose the salts into the soil the moment it touches it, but rather moves salts below the root area.”

He calls this process the dynamic movement of salts in the soil. This animation provides a visual illustration of this process at work:

Research: California State University

In 2018 the Center for Irrigation Technology at California State University, Fresno, conducted a third-party validation with AQUA4D®. The study looked at eight soil columns in lab conditions, with 40 gallons of water artificially treated with sodium chloride in order to increase electroconductivity to 2.5 dS/m. Half the soil columns were then given water treated by AQUA4D®, and half were not.

Analysis was conducted after 21 days. It showed that 84 mg of salt per ml was leached from the control soil, while 195 mg/ml was leached from the soil which was irrigated with AQUA4D®. The authors of the report stated: “It can hence be inferred that the AQUA4D treated water can potentially leach 2.3 times more ions per ml of water than the leachate obtained from soil irrigated with the non-treated water.”

With such a powerful impact on salinity, over the years this irrigation technology has attracted significant academic interest looking at its application for leaching without excessive washing or use of chemicals.

Field Results: Almonds (Kings County, CA)

An AQUA4D® system was installed in spring 2019 at a large producer in the Central Valley. Agronomists returned in September to see the effect of water treatment. By analyzing the soil at different depths and the elements within (including Ca, Mg, Na, Cl) they could paint a picture of the exact dynamics generated by AQUA4D® water treatment.

As is clear from the table below, after just 5 months of irrigation with AQUA4D® there was a clear reduction of soil EC and harmful minerals at all levels:

Results in water-smart irrigation for almonds with aqua4d in central valley california
Field Results: Pistachios (San Joaquin Valley, CA)

In 2019, the AQUA4D agronomist team worked together with various Ag 4.0 measurements to track the progress of its water-smart irrigation for pistachio trees. Two adjacent plots were analyzed, one treated by AQUA4D®, one a control plot.

Firstly, drone surveys by Aerobotics illustrated the effect of these changes on the area cover of the trees. Comparisons of data over just months showed clear increase in area cover compared with the control plots still blighted by salinity, suggesting the tree had benefited in a short time from increased water penetration and reduced salt crystallization.

At the same time, soil sample analysis at Dellavalle Labs Inc. showed astonishing reductions compared with the control, with EC at -85%, Ca -90%, Mg -90% and Na -75% respectively (full detailed results viewable here).

Lastly, Sentek soil probes are equipped with a delicate sensor able to distinguish between soil water content and salt content. Results showed a dynamic process whereby existing salt crystals in the soil were also dissolved, water penetrated much more quickly into the soil, and soil was 23% moister than the control plot.

“We started off with plants that are suffering, with harsh drought conditions and very bad water,” comments AQUA4D’s Jeff Nunes on the recent pistachio projects. “Being able to treat this water showed an astronomical advantage, literally bringing life back to the trees.”

This echoes previous results seen with pistachio producers in Iran, where trees which had not produced fruit for 7 years to due salinity, bore fruit again in the first year after being irrigated with AQUA4D®.


These field results are just two of many examples of the hugely beneficial effects irrigation with AQUA4D® can have on the development of almond and pistachio trees. Long-standing salinity issues have been overcome without applying chemicals or water-intensive washing. And importantly, the soil itself has been regenerated and fit for purpose for years to come.

Alongside saving labor by keeping irrigation systems clean and free of clogging, AQUA4D is proving itself as an ultra-efficient solution for plants, systems, and growers alike.

Find out more: www.aqua4d.com    |   Aqua4D US LLC, 2726 Beverly Ave, Clovis CA

Watch: Jeff Nunes talks us through the changes he observed at a pistachio orchard in the San Joaquin Valley:

  • Californie

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The AQUA4D Skid for high flow-rates

aqua4d efficient water treatment for almonds central valley california

Solar-powered AQUA4D treatment system in Kings County, CA

AQUA4D installation at pistachio grower in San Joaquin Valley