New study claims flaws in processes used to justify artificial turf sports fields

A new peer reviewed study has challenged the validity of many council and regional sports strategies which have led to the recent proliferation of synthetic sports fields across Sydney.

The study, Winter usage, wear and carrying capacity of  sporting fields in the Sydney Basin, completed by soil scientist, Dr Mick Battam, was based on the usage of 1157 playing fields in 24 local government authorities across the Sydney basin.

Suggesting that the findings are “conclusive”, Dr Battram advised “the evidence is crystal clear that many councils are justifying installing expensive synthetic fields based on flawed usage data.

“It is incumbent on decision makers to base sports strategies and expenditure of public funds on sound science as opposed to marketing material and unsubstantiated rules of thumb.

“This is even more important given the exorbitant cost to ratepayers of synthetic fields.

“A typical synthetic field costs twice as much per hectare as what it did to completely replace the entire MCG reinforced sand profile and turf surface in 2014.”

Dr Battram pointed out that the common approach of many sport strategies is to use booked hours to assess sports field usage and calculate future need on the assumption that natural turf can only handle 25 hours per week of use.

Dr Battram went on to suggest that this “incorrect 25-hour limit is then used to the determine the number of fields that are ‘overused’.”

The study found 99% of council-fields in the Sydney councils are used less than 46 hours per week, advising “this is consistent with the limitations that work, school, sleep and other commitments place on when formal sport can be played.”

Dr Battam’s study shows the use of booked hours as a basis for determining if fields are overused is not justified because firstly, it is common practice for clubs to blanket book (reserve) fields for longer than they need them, and secondly not every hour of use is equal - an hour of an adult football game has a greater impact than an hour of under 8s rugby league training.

He added “the data shows that booked hours were typically more than double the actual usage hours in Western Sydney.

“Clearly the figures for booked hours should not be used to calculate need” he said.

The study also highlighted that natural turf fields can have large differences in carrying capacity depending on site characteristics (soil, turf type, microclimate, drainage, etc.). Therefore, there is no scientific basis to rely on the 25-hour number to describe the carrying capacity of all natural turf fields.

Many natural turf fields were struggling despite having low levels of wear, while other natural turf fields were performing well despite receiving high to extreme levels of wear (350-600+ players per week). Those well performing natural turf fields had fertile soil, the right turf variety, weed control and effective drainage.

He noted “turf farmers can harvest turf rolls in September (selling all the grass with 15 mm of soil attached), with the bare ground able to regenerate so the same paddock can be harvested again in February. Therefore, with appropriate management, a natural turf sporting field should easily recover from winter sport.”

Dr Battam found the reason many natural turf fields struggled is because of poor construction and/or maintenance practices. Practices such not applying enough fertiliser, not controlling weeds, or rebuilding a field using a cheap turf variety that laid on hard-setting soil are bound to lead to failure.

He added “the key issues holding natural turf sporting fields are a lack of knowledge to correctly identify the causes of poor turf performance and lack of funding to address them.

“One of the most intensely used fields in Sydney does not even have an automatic irrigation system ($150,000) even though this council has spent more than $10 million dollars installing synthetic fields.”

Jenny Zadro, Market Development Manager for Turf Australia, which partly funded the report, says the findings add further weight to the arguments against the need for synthetic turf.

Zadro stated “the risks and dangers surrounding synthetic turf are well established and this study effectively demolishes the myth that natural turf cannot handle the workload.

“Modern natural turf fields that are properly built and maintained, using sound soil science and suitable turf varieties, can give councils what they need without the massive financial costs and environmental damage”.

Dr Mick Battam is Principal soil scientist for AgEnviro Solutions.

The report, backed by the Sports Turf Association NSW Inc, Turf Australia and Turf NSW, notes "this report was written in a certain way, with a certain budget, for a specific intention."

Click here to view the report.