Soil surfactants and organic matter

This is the last part of our 2022 research into soil surfactants. After testing 7 commercial soil surfactants for criteria such as their effects on surface hardness and disease suppression effects we looked at their impact on soil organic matter (SOM). We cannot find any work referencing if the use of these has any impact on SOM levels. So as independent turf agronomists we decided to do it ourselves.

Plugs were taken from all 54 plots and underwent loss of ignition (LOI) testing. They were dried at 60C for 48 hours before being ashed at 440C for 4 hours. The SOM contents were then calculated at 0-2cm, 2-4cm and 4-6cm.

Products tested were:

  • Treatment 1: Tricure (Mitchells);
  • Treatment 2: HyroForce Ultra (Indigo);
  • Treatment 3: A proprietary formulation;
  • Treatment 4: Propel (Floratine)
  • Treatment 5: Hydroforce Recovery (Indigo);
  • Treatment 6: Untreated control;
  • Treatment 7: Half rates of Hydroforce Ultra;
  • Treaetment 8: H20 Maximizer (Underhill) and
  • Treatment 9: HydroLink Rapid (Globe).

Do soil surfactants impact on the overall organic matter content?

Over the entire depth of the samples (0-6cm) no significant differences were seen in OM contents in comparison to the untreated control. However, this doesn’t answer any questions relating to the development of surface organic matter.

Mean Organic matter contents to 6cm depth
Significant differences between wetting agents treatments and their effect on SOM
Overall mean Organic matter contents by plot

The impact of soil surfactants on organic matter 0-2cm depth – surface organic matter content

Again no significant differences but Treatment 1 (Tricure) did have the highest SOM content.

Mean organic matter contents after wetting agent treatment 0-2cm
significant differences between soil wetting agent treatments at 0-2cm

Organic matter 2-4cm depth

Some interesting results here. Treatments 4 (Propel), 3 (Proprietary), and 8 (H20 Maximizer) all show significantly higher SOM contents at the 2-4cm depth at the 90% significance level. Whether this is as a result of a build up of SOM or an increase in root density is difficult to say based on this trial alone. The lowest SOM content was the untreated control.

Mean organic matter content 2-4cm depth after treatment with a soil surfactant
Significant SOM contents by treatment at a depth of 4-6cm

Organic matter at 4-6cm depth

There were no significant differences in organic matter compared to the untreated control at the 4-6cm depth. The lowest organic matter content was the untreated control.

Mean organic matter content 4-6cm after soil surfactant treatment
Significant organic matter contents by treatment at a depth of 4-6cm

Discussion of results

The first thing is that this trial is limited in what it can show.

  • The trial ran for 200 days but ideally a longer term study would show more conclusive results;
  • Applications were made every four weeks which means in some instances the wetting agent activity may have stopped;
Senior Turf Agronomist at Gilba Solutions Pty Ltd | 0499975819 | Website | + posts

Graduated from Newcastle University with an Hons Degree in Soil Science in 1988, Jerry then worked for the Sports Turf Research Institute (STRI) as a turf agronomist before emigrating to Australia in 1993.

He followed this by gaining a Grad Dip in Business Management from UTS. He has worked in a number of management roles for companies as diverse as Samsung Australia, Arthur Yates and Paton Fertilizers.

He has always had a strong affinity with the Australian sports turf industry and as a result he established Gilba Solutions as an independent sports turf consultancy in 1993. Jerry has written over 100 articles and two books on a wide range of topics such as Turf Pesticides and Nutrition which have been published in Australia and overseas.