Threat to Perth’s Sports Grounds

Recent studies have shown that the people of WA see increasing value in sport and recreational green spaces.  Participation in outdoor sports, particularly for children, is going through the roof, a real positive in this new “couch potato” age of digital entertainment.

There is a divide surfacing between established and new suburbs highlighted by a Department of Sport and Recreation report, which pointed out the difficulties of providing adequate playing surfaces to newly emerging suburbs.  This can be summed up in one word - water. The lack of water for sporting grounds is a serious limiting factor for suburbs from Alkimos to Byford. 

To make matters worse, a microscopic worm that eats the roots of turf grass plants from below, is causing concern right across the metropolitan area. This tiny organism does not discriminate between leafy older suburbs and the newest.  The sting nematode has been identified as the culprit and its control is a deeply vexing issue.  Nematicides are available but these are amongst the most toxic of chemical treatments. These pose danger to contractors who apply them and the children who subsequently play on the sprayed turf. Under the soil the nematicides create dead zones where pretty much all the biology perishes.

When Mandurah City Council faced this nematode threat to its newly opened Meadow Springs sports complex the first thought was to dig up the grass and underlying sand and replace with new sand and roll-on grass at a cost of some $900,000.  They opted instead for an experimental treatment with a composted top dressing product. To the disbelief of many, the nematodes appeared to disappear, the grass grew back looking better than ever and the cost - around 5% of the replacement treatment.

What was happening here?  While the numbers of the destructive sting nematode declined to almost undetectable levels there was a mixed population of other nematodes still present.  These forms didn't eat grass roots.  Essentially the native biology of the soil fought back against the pest nematode and made its life uncomfortable.  I believe that the compost, which contains a greasy black portion called humus has the ability to stimulate the native soil biology in all its complexity to protect its host the lawn plants, from predators. 

Research at the University of WA Turf facility is showing that recreational turf needs a minimum of 7500 litres of water per hectare per year in order to survive in a serviceable fashion in Perth. Some local councils have agreed to lower water allocations for their ovals and active parklands.  When sting nematodes come to these new suburb grounds the result is devastation.  In order to keep an affected lawn green, luxury levels of water are needed.

Research in 2015 by Sports Turf Technology has revealed that in excess of 40% of WA’s recreational turf is infested with damaging levels of sting nematodes.  Over the last few years they have also shown a very clear case for a biological approach using composted products as the most effective treatment.

A further bonus of humus rich composted materials is these improve the soil water holding capacity helping the turf to be more resilient to sudden drought as occurs when irrigation systems have hiccups.