by Bill Crabtree, Agronomist and General Manager of 4Farmers
Aquifer soil wetter is delivering strong establishment and yield gains on WA water repellent sands. This article shares results from a Mindarabin wheat trial comparing Aquifer vs SE14, including placement learnings and ROI.
Aquifer soil wetter trial results
Last year 4Farmers designed a trial to compare wetter placements with wheat. My bias was for behind the press wheel for several reasons;
- Previous work I did with large seeds gave good increases from behind press wheels.
- A Badgingarra trial by Dr Geoff Anderson 10 years ago showed higher wheat biomass from placing wetter behind the press wheel rather than with the seed.
- Numerous trials in WA and SA over last 15 years of placing wetter’s/humectants with the large seeds gave variable and sometimes disappointing responses.
- Two farmers (at Dale and Boyup Brook) told me that that they got really good results from behind the press wheel.
- There is increasing farmer adoption of wetters – they are now used more than with just expensive canola hybrid seed.
Therefore a trial was commissioned by respected Great Southern independent researcher and agronomist.
The trial was sown 17th June on 30 cm row spacings with a DBS seeder on Snow Hill’s farm near Mindarabin. The site was rated severely water repellent.
The nearest official rainfall data is at North Ongerup (shown here) showing some modest rains in early April. Then with virtually no May rain and with good late June rains. The site yielded very well at 2-3 t/ha.
More importantly the response to both Aquifer and SE14 was strong. Even the 1 L/ha gave huge grain yield improvements from either product.
The best result from either product was at 2 L/ha. The average return on investment from all rates is 18:1 for Aquifer while SE14 was 9:1.
Where to place Aquifer?
The 2025 Mindarabin trial also tested placement. See the blue and black lined graph which showed it was best to place the Aquifer with the seed in this trial. This is in the context of very weak opening rains and having some subsoil at depth.
If the opening rains were strong then there might have been some higher leaching power of Aquifer to get to the seed more quickly. So, as you can see we are still learning, but excited by the potential. While these humectants will not be as big a revolution as no-till or GM crops, they are important to get stronger or reliable crop establishment of all crops. As you know, getting the crop out of the ground is vital and dews can work to keep crops growing when you get them.
Is more humectant the way to go?
Most wetters are a combination of wetters and humectants. The ratio of these two is one reason why not all wetters perform the same. Technically humectants are also wetting agents. Soil humectants are defined as substances that attract and retain moisture in the soil, helping to prevent evaporation and ensuring that water remains available for plant roots. They draw atmospheric moisture and condense it into a liquid form, which is then retained in the soil for the plants to use. These compounds are crucial for efficient water management in agriculture, as they help maintain soil moisture levels, especially during drying periods.
4Farmers invented a new wetter with increased humectant in 2025. We call it Aquifer Sustain and while it was equal or slightly better than SE14 it was not as good as Aquifer in this trial. See the green line on the graph. This trial was on typical south coast sandy duplex soil. The increased crop yield from 2L/ha was 750 kg/ha is still very exciting.
Our feeling is that Aquifer Sustain might be better suited to deeper sandy soils as it is designed with extra humectant which does minimise water and nutrient leaching while still promoting wetting.
So, we suspect that Sustain might be a better product on the deeper West Midland sandy soil types, but more research is needed.
In the high rainfall SW corner of WA an excited farmer told me at Wagin Woolerama that in the very dry start with no summer rainfall he found his lupins emerged on a dew only. He was shocked and pleased – me too! He said he gets dews in early May until 11 am and he said obviously dew was pulled into the soil by Aquifer which was placed behind the press wheel. I am not sure how deep he placed the lupins. This was a positive example of Aquifer being placed behind the press wheel – on top of the furrow.
I suspect that Aquifer will likely even have a role on soils that are not water repellent. But I doubt it’s value on clays or medium loams – that would be expecting a miracle. But given paddock soil variability and the low cost of Aquifer it is likely worth keeping Aquifer turned on as you traverse soils to learn. It might also be worth trying at 1 L/ha. But, it will be smart to have two rows turned off and on as you go. If you do this then we would be keen to visit and inspect your results in June.
We know that getting crops out of the ground safely and on minimal rainfall is crucial. Two of our last five years have seen fickle rains at the break of the season and the insurance that 1-2 L/ha of Aquifer gives for only $5.50/L is profound.
Aquifer – better, cheaper!
At $5.50/L send your requests to sales@4farmers.com.au