Hydrogen in the irrigation line: what growers should know

Most growers already manage water, nutrients, light and temperature with great precision. A newer question is starting to appear in horticulture research: can dissolving molecular hydrogen in irrigation water improve how crops grow?

After four decades working with hydrogen technology, I think it's a question worth taking seriously, and worth answering honestly.

What hydrogen-rich irrigation is

The idea is simple. Water passes through a PEM (proton exchange membrane) electrolyser, which generates hydrogen and dissolves it into the water as very fine nano-bubbles. That hydrogen-rich water then goes out through the existing drip, sprinkler or fertigation system. Nothing is added from a bottle or a bag; the hydrogen is made on site from water and electricity.

What the research shows so far

The most useful study I've seen is a two-year greenhouse trial on cherry tomatoes in China (Li et al., Plants, 2024). Hydrogen nano-bubble water at about 1 mg/L was compared with ordinary surface water, with and without conventional fertiliser:

• Yield per plant rose about 40% with hydrogen water alone, compared with plain water, in both years (2021 in Shanghai, 2023 in Nanjing).
• With fertiliser, yield rose about 27–28% more than fertiliser alone.
• Fruit quality also improved: higher sugar content and sugar–acid ratio, and more lycopene.
• The plants took up more nitrogen, phosphorus and potassium from the soil, and the authors propose that soil microbes play a part.

The trial also has limits. It ran at one site each year, with one crop variety. The hydrogen water was applied once, by flood irrigation the day after planting. And the authors themselves say the mechanism still "requires further investigation".

A 2024 review in Frontiers in Food Science and Technology describes molecular hydrogen as a possible green alternative to some chemical fertiliser use. That's a promising direction, but it's still being tested rather than proven.

What this means for a grower

These results don't guarantee a yield increase on your farm. Crops, climates, soils and practices differ. But they are strong enough to justify a properly designed on-farm trial:

• Run it side by side: treat one block or bay with hydrogen-rich water and keep a matched control on your normal regime.
• Measure what matters: yield per plant, grade-out, quality (Brix, colour, shelf life), and fertiliser use.
• Run it for a full crop cycle, ideally two.
• Keep everything else the same, so the result means something.

Practical engineering

For anyone considering a trial, a few points matter more than the brochure:

• Output: a commercial unit should state its water flow and dissolved hydrogen, and how that's measured. Our HERO Irrigation system, for example, delivers 20 L/min at 3,000–5,000 ppb, sensor-measured.
• Installation: it should connect in line, ahead of existing pumps, filters and fertigation, without rebuilding the system.
• Water quality: PEM electrolysis needs clean input water, so RO or low-TDS water is best.
• Hydrogen doesn't stay in water for long. Delivering it close to the root zone, soon after it's made, matters.

The bottom line

Hydrogen-rich irrigation isn't a miracle, and anyone selling it as one should be treated with caution. But the early field evidence is good enough that serious growers, especially in protected cropping, should be testing it on their own crops and measuring the results carefully.

If you run a glasshouse, nursery, vertical farm or orchard and would like to set up a proper trial, I'm happy to talk it through.