Response statement from the WA Turf Industries regarding the research paper;

Written by:

Response statement from the WA Turf Industries regarding the research paper; “An alternative urban green carpet”

1School of Design, University of Western Australia, 35 Stirling Highway, Perth, WA 6001, Australia. 2Department of Urban and Rural Development, Swedish University of Agricultural Sciences, Post Office Box 7012, Uppsala SE-75007, Sweden. 3Department of Ecology, Swedish University of Agricultural Sciences, Post Office Box 7044, Uppsala SE-75007, Sweden. 4Department of Forest Resource Management, Swedish University of Agricultural Sciences, Umeå SE-90183, Sweden. Email maria.ignatieva@uwa.edu.au; marcus.hedblom@slu.se

PERSPECTIVES

How can we move to sustainable lawns in a time of climate change?

The Turf Growers Association WA is always interested in hearing different perspectives from other parts of the world. We acknowledge that the key author of the abovementioned and attached paper is only recently based in WA, and that her research paper was conducted elsewhere and is heavily dependent on literature from Northern Hemisphere research and in our opinion, does not accurately reflect Western Australian context to acknowledge our own special soils and climate before translating the findings of others, and is not relevant to Perth.

No consideration for warm season turfgrasses

Whilst the research papers concede that irrigated natural turf in arid zones enhances urban liveability, there are several concerning recommendations that are not cognisant of the above-mentioned conditions, regarding the use of native grasses to replace irrigated turf. There is no mention in the paper of Kikuyu and couch grasses, (warm season grasses), used extensively in WA for public open space. Notably, kikuyu turf grass is a mat-forming perennial grass which spreads by underground stems (rhizomes) and profusely branched, creeping surface stems that root down at the nodes (stolons), (down to 3 meters) that forms a dense drought tolerant turf cover. It can withstand long periods without water but recover quickly when rewatered. Under regular grazing or cutting it forms a dense turf, but otherwise can grow to about 30 or 40 cm deep with a deep root system (to >3 m). To ignore these warm season varieties that thrive with best practice turf management, even under reduced water allocation, is in our opinion extremely naïve.

Meadows for recreation

The viability of Western Australians playing sports such as cricket, football and soccer on “meadows” of mixed native grasses is quite unreal. Western Australian native grasses do not transpire in the manner that irrigated turf does to provide urban cooling, and they are not suitable surfaces for recreational activities due the inability to handle heavy traffic, the contour of the plant vs soil and the height that they should be maintained at and the endurance of these plants with lack of water under traffic remains untested. Please refer here to view the varieties of native grasses and their suitability in situ for WA conditions: https://www.sgaonline.org.au/lawn-alternatives/ 

Nor has the author considered the environmental concerns that our society has with children playing in long grasses. Venomous snakes and spiders are highly prevalent in WA, even in our urban communities, as are bushfires. The risk of these concerning factors has not been considered at all in this paper. Children cannot recreate in the same manner on mulched or pebbled surfaces as they can on irrigated turf. Families in WA would not encourage children to play in “meadows” due to perceived safety hazards.

It must be noted that in northern Europe, the lifestyle is in no way comparable to that of Western Australia, where community only spends short periods of time in the outdoors due to weather conditions. The CEO of IKEA when visiting Perth, noted that in Sweden and other Nordic countries, they do not stock a decent outdoor range as IKEA does here in Australia since people in these countries do not conduct outdoor activities in the same way as we do here. The paper lacks credibility from this perspective, as it has not considered the different lifestyle behaviours, the vastly different climates, and it doesn’t show an understanding of the attraction for irrigated green space for health and wellbeing in our state. If the author has only been in Western Australia for the past six months, she has not witnessed an Australian summer.

Benefits of Turf

The Department of Education and Training WA and Beyond Blue recognise validly the importance of irrigated turf and greenspaces for mental and physical health and wellbeing in Western Australia. There are numerous independent research findings that support the importance of irrigated green spaces and turf for the many, many benefits to community including; social, environmental, health and economic benefits of turf that have not been appropriately acknowledged in this research paper. The evidence of the importance of irrigated green spaces and turf to liveability has been acknowledged by local, state and the federal governments.

Obesity in Australian children has been a focus in recent years. With less private, quality green spaces and diminishing irrigated public open spaces, children, and their parents are spending more screen time than green time, with activity levels notably down and type 2 diabetes increasing alarmingly. Schools concentrate on educating children on outdoor activities to combat the amount of screen time that occurs in home. Health issues are arising because of “blue light” that comes as the compulsion of screen time increases. Children are not able to play, to recreate outdoors due to already limited quality areas of irrigated green spaces, turf.

Water Consumption

The references within the paper to water consumption are not profound, and without consideration for our free draining sands and aquifer recharge potential, for Western Australian circumstance and reality. The paper cites that “in arid regions of the United States, lawn irrigation accounts for 75% of the total annual household water consumption” this is not comparable to Perth, where outdated Water Corporation data specifies that 40% of water usage is outdoors, and not all of that is for irrigated turf. This includes, gardens, pools and other outdoor activities. To use Northern hemisphere data without legitimising the correlation to WA conditions and environmental circumstance shows ignorance, by not to referencing WA data and information directly doesn’t reflect well on the researcher.

There is no mention of solutions for water use other than to decrease or remove a living plant system that is proven to combat urban heat island effect. The matter of provision of water to service community for betterment and quality of life is not considered in this paper. The privatisation of water, better water reuse and recycling, storm water harvesting for POS, and many other alternatives, must be a priority focus for government and industry groups. A positive for the people of Perth would be the development of a working group to long term plan for Perth’s future; how we want it to be/look. This would require commitment from unified government departments and agencies, community and industry groups, as a matter or priority and would be welcomed.

Water Contamination

References to water contamination and run off are also based on Northern hemisphere literature. University of Western Australia research and independent research undertaken in WA, has demonstrated on numerous occasions that nutrient leaching in WA is very low under current watering and fertilising regimes and is not comparable to studies undertaken elsewhere in the world despite our free draining sandy soils.

The paper specifically cites pesticides as being of concern for water contamination. “Another concern is the contamination of groundwater or runoff water due to overuse of fertilizers, herbicides, and pesticides. In 2012, the U.S. home and garden sector used 27 million kg of pesticides”. This in no way reflects the habits and usage of said chemicals here in WA.  Pesticide usage in WA has been greatly restricted over recent years due to community concerns across most of local government authorities. Pesticides usage in WA is extremely well legislated and regulated, with several chemicals previously used for pest management now restricted or banned. Fertilisewise legislation regulates the usage of phosphorous in WA with bagged fertilisers not being allowed more than 1% phosphorous. Newer turf related fertilisers incorporate carbon and humic and are far more environmentally friendly. The turf industry urges best practice fertilising and is very responsible with recommendations regarding this. Herbicides in WA are also well regulated by the state government and overall responsibly managed by LGA’s and experienced turf managers. It is our opinion that the comments pertaining to pesticides, herbicides and fertilisers, are not entirely valid nor pertinent to WA. CSIRO conducted a study many years ago with a finding that dog faeces was potentially more of an issue than best practice fertilising.

Carbon Footprint

Regarding comments on the carbon footprint of turf, the researcher has not noted the WA Department of Sport and Recreation document “Natural grass vs synthetic turf”. This respected, comprehensive and fair document notes Natural grass helps remove carbon dioxide from the atmosphere through photosynthesis and stores it as organic carbon in soil, making them important “carbon sinks.” A typical lawn (2,500 sq. ft./232 m2) converts enough carbon dioxide from the atmosphere to provide adequate oxygen for a family of four. [9] There is some recent research from the United States that suggests greenhouse gas emissions from fertiliser production (mowing, leaf blowing and other lawn management practices) are greater than, the amount of carbon that can be stored in them, suggesting that natural grass may contribute to global warming rather than reduce it.  This study also found that athletic sports fields do not store as much carbon as ornamental grass due to soil disruption by tilling and resodding.[10] However, it was later discovered that there were several computation errors in this research and when the computations were corrected, it was found that natural grass actually is a net sequesterer of carbon dioxide, reversing the conclusions of the original report.[11]  This is backed up by another recent US study that concludes “After reviewing the direct carbon sequestration of grasses and their root systems, we found that managed lawns sequester, or store, significant amounts of carbon, capturing four times more carbon from the air than is produced by the engine of today’s typical lawnmower. The study also finds that well-managed turfgrasses (natural) that are cut regularly and at the appropriate height, fed with nutrients left by grass clippings, watered in a responsible way, and not disturbed at the root zone actively pull pollutants from the air, creating a greater carbon benefit.”[12]

It must also be noted that whilst synthetic turf does not require mowing, it still does require ongoing maintenance, often using fuel powered machinery to help keep it clean and performing well.  Ride on mowers with brushes rather than mowing blades are used to brush the surface and leaf blowers are also used to remove leaves from fields. This maintenance equipment produces greenhouse gas emissions but unlike natural grass there is no carbon sink to counter balance it.

Often artificial turf replaces a natural grass surface, so another contribution synthetic turf makes to global warming is the removal of a natural grass surface that reduces carbon dioxide, by converting it into oxygen. [13]

https://www.dsr.wa.gov.au/support-and-advice/facility-management/developing-facilities/natural-grass-vs-synthetic-turf-study-report/broader-environmental-considerations

Unfortunately, no formal greenhouse gas life cycle analysis for turf grasses has been completed here in WA. This is something that the WA Turf Industry would welcome and will endeavour to discuss at a UWA Turf Industries Research Steering Committee meeting soon. Overseas studies of this nature are limited and not generally applicable to WA. Turf has a huge potential as a carbon sink, and as such, WA will develop a project proposal for this as a matter of priority.

The matter of carbon footprint domestically did not consider the footprint of the current trend of a far bigger house being built on a much smaller lot, as is the norm in newer Perth suburbs. Nor did it consider the urban infill program, whereby air conditioners and clothes dryers are over utilised with less private greenspace to cool homes and the environment.

Hydro-zoning

On the matter of hydro-zoning, this already happening across many local government authorities in Perth, where areas on the edges of parklands, golf courses and ovals, have been replanted with trees and shrubs as unirrigated spaces. Community safety has been factored in to this, and it is hoped that landscape architects and designers are using Western Australia native species, that encourage habitat for our endangered native fauna, such as the Carnaby and red-tailed cockatoos. Eastern states natives, and olive groves have a place, however genuine consideration for our native fauna species should be a prioritised.

Synthetic Turf

We do however congratulate the author for highlighting concerns and her comments on synthetic turf. Synthetic turf in sporting turf uses more water than natural turf. Synthetic turf creates a heat island effect comparative to concrete and asphalt. In contrast, irrigated natural turf that has been found to be cooler for the environment than a shallow lake. Sporting injuries, and health risks from synthetic turf, in recent times have become concerning, across the globe. For practical reasons in domestic circumstance, synthetic also creates issues, being too hot to for pets and children to live and play on in warmer months in Australia, with heat burns from the surface becoming more prevalent as usage increases.

A full life cycle analysis of synthetic turf comparative to natural turf is a project that we need to undertake, taking into consideration heat island and cooling effect, dust and contaminates, health risks and storm water harvesting aspects. Heat island effect in Australia climactic conditions, is potentially more profound than in the Northern Hemisphere. Heat stress, heat island and the temperatures of synthetic turf and hardscapes in our environment, must surely be more significant.

Hot, dead earth isn’t good for any living creature this is an obvious fact, nor for urban canopies, for without the, carpet under the canopy, urban trees cannot survive with rising temperatures. Local government authorities are already battling the issue of potential tree loss and how to replace aged canopy trees with a fast-growing substitute that will sustain with rising temperatures. Notably, tourist destination and seaside, port town, the City of Fremantle, are facing the loss of long-established native street trees (Agonis) due to rising temperatures and the trees inability to survive in the concrete environment. Concerningly, established trees are being removed for infill development and new suburbs excessively. Tree canopies in WA are not comparable to that of Northern Europe, nor do our native trees expire in the same manner.

Water Allocations

Turf managers and producers in WA take extremely seriously the responsibility of water allocation usage and nutrient leaching. The challenge across industry being to maintain quality turf for community under the pressure of decreasing ground water allocation. The focus of departments on aged research to justify this Industry best practice sees much of Perth and surrounds public open spaces vital and viable. Smart technologies such as smart irrigation controllers, soil moisture sensors, and the appropriate amending of sands to soils, commitment to using quality wetting agents and soil moisture retainers, organic fertilising with carbon and humic matter fertilisers that are ecofriendly and phosphorous legislations etc, we firmly believe that WA can have our home lawns and public greenspaces such as parks and sporting fields and walk, play, exercise and lie on them too without guilt. The many, many benefits of lawns or turf, environmentally, for health and wellbeing, socially and economically that do not appear to have been addressed by this research.

Proactively the turf industry in WA will endeavour to encourage the national peak body to conduct a full cost benefit analysis on the environmental and economic value of turf in Australia, broken down to state levels.

CONCLUSION:

Overall, the paper appears to be very simplistic, drawing on northern hemisphere data, without appropriate consideration or evaluation of Western Australian circumstance. It does not seem to fit with current urban greening trends in Australia and is seriously lacking in content pertinent to Perth, Western Australia. The WA Turf Industry sees this research as being a knee jerk reaction that does not afford this paper credibility.

CONTACT:

Eva Ricci
Executive Officer
WA Turf Industry
eva.ricci@turfwa.com.au
M: 0422 120 990

Comments