Provisioning

Many Queensland seaside gardens are established on sandy soils low in essential plant nutrients but high in sodium chloride, or common salt.

The secret to achieving a good lawn cover in these exposed and sodium-rich soils is to find turf varieties that grow in salty soils. These are known as halophytic turf grasses. The following are the top four species for coastal conditions

Seashore paspalum (Paspalum vaginatum)

This turf grass will cope with occasional inundation by sea water.

It has a fine to medium leaf texture and produces a lush green cover. It tolerates relatively low fertility levels.

The three main varieties available in Queensland are Sea Isle 1, Sea Isle 2000 and Velvetene.

Buffalo grass (Stenotaphrum secundatum)

This grass is also called St Augustine grass in the United States.

Stenotaphrum secundatum can be confused with broadleaf carpetgrass (Axonopus compressus), which is commonly referred to as ‘buffalo grass’ in Far North Queensland.

S. secundatum is a similarly coarse-textured grass with a much higher tolerance of saline conditions compared to broadleaf carpetgrass, which can often be found in wet, shady spots in southern Queensland lawns.

The turf research group at the Department of Employment, Economic Development and Innovation (DEEDI) Redlands Research Station is evaluating buffalo grass selections for salinity tolerance. Buffalo grass is suitable for warmer parts of South East and Central Queensland. It is less suited to the coastal tropics as it thatches heavily.

Manila grass (Zoysia matrella)

Manila grass produces a tight, fine-textured and attractive lawn.

It is slow growing and only available from a few selected turf suppliers.

Green couch (Cynodon dactylon)

Green couch is a popular choice for gardeners along the coast, however it is known to be less tolerant of salinity than the above-listed species. It is also affected by low light levels during the extended tropical wet season.

The DEEDI turf research group has evaluated Australian green couch selections for their salinity tolerance. Of the overseas cultivars available in Australia, FLoraTeX has shown a higher degree of salt tolerance than other varieties in US trials. Hatfield and Oz-E-Green equalled the salinity tolerance of FLoraTeX in QPIF trials and Mountain Green (which is adapted for the tropics) also demonstrated a high level of salt tolerance.

Glossary

Thatch: A layer of dead grass between the leafy green vegetation and the soil surface. Thatch should be removed periodically to maintain lawn health.

Australia is the driest inhabited continent on Earth. It is about 80% of the USA´s land area, but supports only 21 million people compared with just over 300 million in the USA.

Australia’s population is concentrated in the limited areas with higher rainfall along the eastern, southern and south-western coasts. Water, or lack thereof, is the major reason for Australia´s low population.

Australia has:

• 1% of the world´s surface fresh water resource
• only a few snow-fed rivers
• less than 300 mm average annual rainfall across 60% of the country, while another 20% receives 300-600 mm
• highly variable rainfall from year to year
• experienced 12 major droughts in the past 150 years.

Australia´s water crisis

In a dry continent currently in the grip of one of the worst droughts on record and with unprecedented water restrictions, making better use of our water must be a priority.

The theme of water use runs through much of the Department of Employment, Economic Development and Innovation’s (DEEDI’s) turf research program on warm-season grasses at the Redlands Reseach Station. It is critical long-term research be conducted into better and more water-effective solutions to apply during the ongoing cycle of droughts in Australia.

No ‘silver bullet’ solution

Homeowners and the media want a quick fix: ‘Just give us your most drought-tolerant grass’ is the usual request. But even the most drought-tolerant grass will not survive in a few centimetres of soil over rock, which is not an unusual situation in new housing developments.

One major building company promises customers 300 square metres of lawn laid on just 5 cm of topsoil around their new house. This amount of topsoil is grossly inadequate and is actually being promoted as a positive marketing tool.

The plant itself sets the potential in terms of the level of drought tolerance that is possible. The soil profile in which it is grown and the management practices applied determine how much of that potential can actually be achieved.

Drought-tolerant turf is built from the ground up by making a series of incremental improvements, not through one simple solution.

The basic steps are:

• to put a good soil profile in place
• to ensure that water can enter the soil and be stored there for the plants to use
• to plant a well adapted turfgrass, bearing in mind other site restrictions such as shade, wear or salinity
• to check water quality, particularly in the case of alternative irrigation supplies.

Water use efficiency or drought tolerance?

Firstly, we need to be clear about our objective: Are we looking for better water use efficiency in our turf, or the ability to survive for longer periods while losing water through evapotranspiration? The answer depends on climatic conditions and the chances of rainfall.

In a desert climate where there is very little chance of rainfall, the turf is reliant on total irrigation. In this context, water use efficiency is important, even though recent research in Arizona by Kopec and others (2006) showed only small differences among the various species and cultivars used.

In a humid, subtropical climate like Brisbane, where there is much higher probability of rain in the near future, irrigation is generally used to supplement rainfall on turfed areas. This means that drought-tolerant turf that can go longer between rainfall can lead to substantial savings in irrigation water use.

Start with the soil profile

When grown on a properly-constructed soil profile in South East Queensland, most warm-season, drought-tolerant species will survive long periods of drought without any irrigation, such as green couch (Cynodon dactylon and hybrids) and blue couch (Digitaria didactyla). The less drought-resistant ones need no more than an occasional strategic watering to survive.

For turf to cope with extended dry periods, the soil profile should be a minimum of 10 cm (and preferably 15 cm or more) deep to provide adequate soil water storage. Where the profile depth varies, shallow patches will dry out more rapidly and the turf on these may even appear dead by the next fall of rain. But with moisture in the profile once again, many such apparently ´dead´ patches of blue and green couch can stage a rapid and complete recovery.

Not only is the depth of topsoil under the turf important, so is the quality of that topsoil. For example, second-rate soil stripped from a building site will not give the desired result.

Increasingly, soil suppliers are mixing components to create artificial soils, as sources of good natural topsoil become scarcer. Products with raw compost that is still decomposing should be avoided. Additionally, soil mixes with high organic matter (greater than 25%) will eventually slump to lower levels as the organic matter decomposes. This is an area where more research and more regulation is required to improve the quality of topsoil used under new turf plantings.

Soil water entry and storage

At low moisture levels, many soils will become water repellent, a problem caused by organic acids coating the sand or soil particles. Rainfall and irrigation are then much less effective, as water tends to run off or through the soil and it does not easily wet up again. While this is a common problem seen on golf greens, it is not widely recognised that soil water repellency is also a common condition on the extensive areas of infertile forest soils found in urban areas around Brisbane.

The normal treatment for soil water repellency in high-quality turf areas is to make regular applications of surfactants, which improve water entry by reducing surface tension. Research on new generation surfactants has demonstrated their effectiveness in improving infiltration. By maximising the amount of water captured in the soil during short, high intensity storms, improved infiltration in areas treated with surfactant translated into visibly better turf quality.

Newly-laid sod of all turfgrasses has only a limited root system and is vulnerable to drying out. Regular irrigation is needed until deeper roots have grown through the turf underlay. A number of soil amendment products (e.g. cross-linked polyacrylamides and water-absorbent foam) have been developed to improve soil water-holding capacity. The role of these products in turf establishment was assessed by the Redlands turf team through a research grant from the International Turf Producers Foundation.

Plant a well-adapted turfgrass

There is no such thing as a perfect turfgrass, or one that will grow everywhere and under all conditions. Drought tolerance is not the only attribute to be considered when selecting a turfgrass.

Some 25% of turfgrass sites, for example, are affected by shade, where the most drought-tolerant species – green and blue couch – do not perform well. Buffalo grass (Stenotaphrum secundatum), manila grass (Zoysia matrella) and sweet smothergrass (Dactyloctenium australe) grow much better than green and blue couch under shade, and maintain green healthy turf much longer than they would in full sunlight.

While larger differences in drought tolerance are found among species, differences within species also occur, which will help maximise water savings. The Redlands turf team in collaboration with University of Queensland (UQ) scientists received a government grant to develop more drought-tolerant turfgrass cultivars for a range of uses. The project focuses on collecting and evaluating Australian Cynodon genotypes for turf quality and drought tolerance.

Water quality

Using poor quality alternative water sources, including greywater, invariably means that salinity will be an issue. Research at Redlands has been directed towards growing turf on salt-affected soils, and has identified salt-tolerant turfgrasses that can also be used with poor quality water.

In the first project, 41 turfgrass cultivars from 9 different species were screened hydroponically to assess their tolerance to salt levels up to 40 deciSiemens per metre, which is 74% of the salt level in seawater. In addition to confirming the high levels of salt tolerance in seashore paspalum (Paspalum vaginatum) and manila grass shown in US work, there was considerable variation in salt tolerance among buffalo grass and green couch cultivars, enabling the more tolerant cultivars to be specified for future use on moderately saline sites.

Water use of turf versus landscape plants

Garden commentators promoting shrubs and trees in the media often describe turf as a high water user. This could not be further from the truth.

Savings in water use on community-level sports fields are still possible without compromising turf quality or playability. Researchers at the DEEDI’s Redlands Reseach Station looked at year-round water use across a number of soil-based community sports fields in Brisbane. Under normal frequent irrigation scheduling, the average field uses around 5 ML/ha. Strategic weekly irrigation (applied only when no rain had fallen in the previous week and surface soil moisture was rapidly declining) still maintained good turf quality and a safe playing surface, but on average required less than half the irrigation water (about 2.4 ML/ha). By comparison, tree crops such as citrus typically require 5.0 to 7.5 ML/ha.

These and other facts about water use should be publicised by the turf industry, in addition to commissioning further research to compare reticulated water use on turf and on shrubs and trees. In Florida, Park and Cisar (2006) showed that, after the first year when more water was used to establish the turf, their shrub landscape used more water than the turfed landscape, and water use by the shrubs continued to increase as they grew larger, while turf water use stabilised.

We need studies of this kind in Australia to help get the message across to the public that turf is not a high water user, but rather a sustainable and environmentally-friendly option as the pressure on urban water supplies increases.

Acknowledgement

This information was developed from an article that was first published in TurfCraft International, Issue No. 117, November-December 2007, pages 30, 32.

References

Kopec, D.M., Nolan, S., Brown, P.W. and Pessarakli, M. (2006). Water and turfgrass in the arid southwest. USGA Green Section Record 44(6), 12-14. Also available electronically.

Park, D.M. and Cisar, J.L. (2006). Documenting water use from contrasting urban landscapes: Turf versus ornamentals. TPI Turf News 29(3), 38, 40-42.

Seminar information

This information also featured in a seminar entitled ‘Turf for tough times: Keeping grass cover with less water’. The seminar was conducted by the then DPIF’s (now DEEDI’s) Redlands turf team in Brisbane on 6 June 2007 and was repeated in Toowoomba on 30 October 2007. Other topics covered by the six presenters included:

• irrigation management on sports fields
• using recycled water for irrigation and its implications for soil health
• how good soil management can improve outcomes in dry times
• wear tolerance of different grasses
• progress results from soil amendment trials.

Copies of the 40-page seminar proceedings can be purchased for $18.50 (including postage and GST) by writing to:

Redlands Research Station,
Department of Employment, Economic Development and Innovation,
PO Box 327,
Cleveland Queensland 4163

Ph: +61 7 3286 1488, Fax: +61 7 3286 3094, email: cynthia.carson@deedi.qld.gov.au

Cheques should be made payable to the Department of Employment, Economic Development and Innovation.

The key to success with lawns

Many common challenges facing lawns – including weed growth, wear, drying out and even plants’ ability to cope with pests and diseases – can be traced to problems with the physical condition of the soil.

Good soil physical conditions are required to support healthy root systems, the key to success with lawns.

A strong root system is the best defence a lawn can have against weeds, wear, drying out, pests and diseases. The roots will exploit available soil moisture and nutrients, and support dense top growth. The resulting lawn will then have the vigour required to keep weeds at bay and recover rapidly from wear, pests and diseases.

Soil physical conditions

When we talk about the physical condition of soil, we are referring to attributes such as its hardness, compaction layers, depth, ability to drain and structural composition (clay, sand or rock).

While the spotlight is often soil fertility issues such fertiliser requirements and pH, maintaining the physical condition of a lawn’s soil is often neglected.

Measuring soil depth and condition

A common, and often misunderstood, problem in lawns is shallow topsoils.

The softer surface layer of soil is often accompanied by a much harder (often clay) subsoil.

A quick method of gauging the depth of a topsoil is the ‘penetrometer test’. This method works best 24 hours after heavy rain or a good irrigation. The soil needs to be damp, but not saturated.

A makeshift penetrometer can be made out of a 40 cm length of 3 mm fencing wire. Bend the first 15 cm of wire into a loop to make a curved handle. Straighten the remaining wire and file notches at 2 cm intervals along the length from the tip.

Test for soil depth and compaction by applying a constant downward force, exerting a moderate pressure on the handle.

You will find that your penetrometer is easy to push through a good-quality topsoil, but becomes harder to push at the boundary between topsoil and substrate. Stop at that point and measure the depth of entry of the wire into the soil. If you hit a rock or tree root, try an adjacent spot.

By repeating this process in a regular pattern across your lawn, it is easy to quickly determine localised problem areas, as well more generalised problems.

Insert the penetrometer vertically into the soil

Lawns require a minimum root-entry depth of 100 mm. However, 200 mm, and preferably 300 mm, is ideal for conserving soil moisture and maintaining lawns between sparse falls of rain in coastal South East Queensland.

A spade is another valuable soil analysis tool. Dig into the soil to check on the volume of rock and presence of hard, compacted layers within the soil. Rocks and hard layers reduce the effective volume available for roots to exploit, which in turn reduces top growth.

With most new homes being constructed on a base that has been cut and filled, and with topsoil having been removed from some estates, most homes have at least some areas of soil with poor physical properties.

Problems with shallow soils
The harder and more impervious any layers are, the more important it is to increase the depth of your topsoil to support your lawn.

In addition to the impact on potential root mass, hard layers:

• make soil dry during low rainfall periods
• make soil prone to flooding, which drowns the turf, during heavy rain
• increase runoff and promote erosion, which reduces soil depth. When erosion occurs, sediment, fertilisers and applied chemicals are then carried into waterways, creating environmental problems
• expose the soil to temperature extremes which can kill off parts of the root system
• reduce vital soil oxygen supplies needed to sustain root systems
• reduce the potential of a soil to supply nutrients.

Lawns will not survive long dry periods if their root systems and growing soils are shallow. With more extreme weather predicted, soil’s physical condition will become even more important.

Shallow soils are particularly vulnerable to erosion during heavy rains

What depth?

Dr Rachel Poulter, from the Department of Employment, Economic Development and Innovation (DEEDI), showed that major water savings can be made by increasing the depth of topsoil from 100 mm to 200 mm.

Using rainfall data from Cleveland, Queensland, she calculated that the effective water saving, applied over 150 square metres of turf for a year, was 19,000 litres.

In addition, increasing the depth of topsoil from 100 mm to 300 mm resulted in an effective water saving applied over the same area of turf over a year of 29,300 litres.

She also found that topsoil depths of 50-100 mm were inadequate for efficient water storage for use by a lawn between periods of rain.

Dealing with shallow soils

Changing varieties or re-laying turf will rarely improve the outcomes of a lawn laid on a soil with physical problems, as the fundamental requirements for the growth of any new turf are still absent.

However, here are some things that can be done:

• Aim for a minimum topsoil depth of 200 mm.
• If possible, increase soil depth using available top soil already on site.
• Import quality new soil. Imported soil needs to have a minimum available water holding capacity of 15% by volume. Soil should meet the Australian Standard AS4419 ‘Soils for landscaping and gardening use’. Check whether your soil supplier meets these standards. Some manufactured soils are very high in organic matter which will break down over time. This causes slumping and is particularly troublesome in lawns.
• Have a soil analysis done and attempt to restructure clay soils by incorporating gypsum and organic matter. Cultivating the subsoil (e.g. with a rotary hoe) may help to mix amendments in while also improving the soil’s physical condition.

Further information

• Northern Rivers Soil Health Card, Department of Primary Industries, New South Wales, 2002

A common perception is that turf grass is a high water user. But is this true? Generally not, unless referring to heavily managed species that are not naturally suited to Queensland.

Slight shifts in turf grass selection and modest changes in management systems produce a result for every drop of water applied. Most warm-season turf grasses experience some browning due to water stress, but quickly recover when rain falls.

International research

In a landmark study, University of Florida researchers carefully documented water use in a buffalo grass (Stenotaphrum secundatum) lawn and an adjacent native (to the United States) mixed species landscape, under similar environmental conditions to those encountered in South East Queensland.

Test landscapes, each measuring 5 x 10 metres, were replicated eight times to provide rigorous scientific measurements.

Results

• Year 1: When both the lawn and the landscape species were establishing, the yearly irrigation requirement (in addition to rainfall) for lawn was 964 mm per year, 83 mm more than the adjacent landscape.
• Year 2: The irrigation requirement for the lawn (233 mm per year) was still 129 mm higher that for the adjacent shrubs.
• Year 3: By the third year there was no difference between the two.
• Year 4: The landscape plants were using significantly more water (254 mm per year) than the adjacent turf (109 mm per year).

Changing water requirements

So what do the results show? After the initial establishment year, the irrigation requirements for the landscape shrubs continued to rise from 104 mm per year in the second year to 254 mm per year in the fourth year.

Plant water use measured as evapotranspiration also rose. This was attributed to the ongoing growth of the leaf canopy with time. The water requirement continued to rise as the leaf area increased.

In addition, at the rates of irrigation applied, some of the species in the mixed planting developed stress symptoms, indicating that the irrigation needs were not yet met. In a mixed planting, for all plants to look good, the water applied has to meet the needs of the plant using the most water.

Lower lawn water use

In contrast, after the initial establishment phase, the water needs of the mown lawn stabilised. The evapotranspiration level was only higher than the adjacent landscape in the first year, when the landscape canopy was quite small. In the second, third and fourth years, the evapotranspiration figures for the lawn was lower than or equal to that of the adjacent landscape. The buffalo grass lawn was able to survive with low levels of irrigation once established.

The results suggest that lawn has a place as a low water use landscape element, in time outperforming even plantings native to an area.

Further information

Park, DM and Cisar, JL 2005, ‘Documenting water use from contrasting urban landscapes – turf vs. ornamentals’, TPI Turf News, May/June: 38-42.

On this page:

• Selecting the right seed
• Species not suitable for Queensland
• Using soil stabilising species
• Planting turf seeds
• After planting
• Turf rolls or mats

Selecting the right seed

Much of the lawn seed sold by nationally based chains is unsuited to warmer climates. Many of these products are blends containing 85% to 100% cool-season species. The names on the packages do not normally indicate what the species mix is and may actually claim a deceptive range of climatic adaptation. A species list, using either the common name or scientific name, will normally be shown in smaller print somewhere on the packet.

Seed-grown warm-season turf species that will grow in Queensland

Of these, only green couch, Queensland blue couch and kikuyu seed are readily available. Siro Shadegro was developed as a premium shade-tolerant turfgrass species for tropical and subtropical conditions by CSIRO in Brisbane. The Department of Employment, Economic Development and Innovation (DEEDI) at Cleveland has worked with the licensed seed company to bulk up seed of Siro Shadegro prior to wider commercial release.

Narrow-leaf carpet grass, Whittet kikuyu and bahia grass are coarse-textured and need to be used with caution, as they tend to become invasive.

Although green couch is often sold generically (e.g. Speedy couch), there are some named varieties. Generally, these are more vigorous, denser, a darker green and may have other advantages when compared with common green couch. Examples of these improved varieties include Mohawk, Princess 77, Riviera, Sydney, Savannah, Jackpot, Sundevil II and Mirage.

What´s in the bag?

Purchased seed may be hulled or unhulled, or a mixture of both. Hulled seed germinates faster, but is more expensive.

The purity percentage shows how much of the material in the packet consists of seeds of the labelled species, the remainder being inert material or other seeds. The germination percentage indicates how many live seeds there are in the pure seed fraction. For example, a minimum 98% purity and 75% germination means that the seed company warrants that there is a maximum of 2% inert matter and other seeds present, and that at least three quarters of the seeds are viable.

Seeds are sometimes coated with inert materials to improve their flow or to protect them from being taken by insects such as ants before they can germinate in the seedbed. Other inert additives to a bag of seed may include fertilisers to improve seedling growth and wetting agents or hydro-mulches to retain moisture around the seed. None of these inert materials add to the ability of the seeds to germinate; in fact, when fertiliser is mixed so that it comes into contact with the seeds, there is a risk that it may actually reduce potential germination by killing seeds.

Species not suitable for Queensland

It is surprisingly common for temperate climate species to be found in lawn seed blends sold in Queensland; many are budget blends formulated for southern Australia. Check the packet for the following cool-season turf species prior to purchase, as these seeds will not produce a sustainable lawn under Queensland conditions. Although the seed may germinate well, the seedlings will not persist in our warm climate. Any long-term success with such blends in Queensland will be attributable to the presence of small quantities of green couch seed in some mixes.

Soil stabilisers

Green couch can take up to 21 to 28 days to germinate. This leaves an exposed soil surface. Annual and perennial ryegrasses (annual rye is cheaper, but generally with coarser leaves) can be used to give quick short-term cover and stabilise the soil in winter. In summer, a similar effect can be achieved with Japanese millet (Echinochloa crus-galli).

Apply the seed of the stabilising cover species at about 2-3 kg per 100 square metres, for green couch sown at 1-2 kg per 100 square metres. The winter-sown ryegrass will die as soon as temperatures start to rise in late spring. The summer-sown millet similarly recedes in response to cooler temperatures and close mowing.

Planting turf seeds

Warm-season turfgrass seeds can be sown successfully at any time during the growing season from about September to March. During the summer months, however, evaporation is higher (requiring more regular moistening of the seed bed to ensure germination) and weed competition is generally more severe.

Following are the basic steps to achieving a successful seeded lawn.

1. Start with a clean area. Kill any existing lawn and weeds by spraying with glyphosate (Roundup or similar generic products).
2. Loosen soil to a depth of 10 cm. By reducing compaction, the plant roots are able to penetrate deeper into the soil, giving better drought tolerance.
3. Create a seed bed by working the top 2-3 cm to a fine tilth with a steel rake. Purchased sandy loam can assist in creating a favourable environment for seed germination. Remove any large clods.
4. Adjust the soil pH to 6-7 for green couch (but not for blue couch, carpetgrass or kikuyu). Simple soil test kits are available at nurseries. As many coastal Queensland soils are acidic, it may be necessary to raise the pH with lime for green couch.
5. Apply a lawn starter fertiliser. Rake this in well.
6. Level the soil surface.
7. Sow at the recommended rate. A small amount of sand or sawdust can improve the uniformity of distribution of seeds.
8. After sowing, press the seeds into the surface with light rolling or treading, or cover the seed lightly by working a light straight piece of timber across the seeded area.
9. Water well after sowing. Keep the top 2 cm of soil moist by regular light sprinkling.

Note: Local council restrictions on the use of reticulated water may make it difficult to establish seeded lawns in the absence of alternative water sources. Familiarise yourself with local council by-laws on watering prior to starting your project.

Reducing competition from weeds

If time permits, prepare and water the seed bed prior to sowing. This will encourage the germination of the most precocious seeds. Eradicate the emerging seedlings with glyphosate before sowing.

After planting

• Maintain frequent light irrigation until the seedlings have established.
• Restrict the entry of large pets, particularly dogs, into the sown area until the lawn has closed over.
• Check the seed packet for species-specific mowing instructions. Generally seedlings are not mown until they are 80 mm high. Set the mower height at 60 mm to remove only the top 20 mm. This height can be gradually reduced as the lawn develops.

Turf rolls or mats

Although some home owners prefer the economy of establishing a lawn from seed, particularly if they have a large area to plant, there are advantages to buying turf rolls or mats (sod). Instant turf brings your lawn into active service sooner. In addition, a broader range of product choices are available for particular circumstances, and sod is less vulnerable to drying out and invasion by opportunistic weeds. Vegetatively propagated turf grass selections normally outperform seed-grown forms in standardised research trials in the United States. Additionally, seed-grown selections are more likely than vegetative selections to form large numbers of unsightly seed heads at certain times of the year if not regularly mown.

Overview of turf research in Queensland

The Queensland Government’s turf research program is the largest of its kind in Australia. Established in 2000, the program supports the state’s turf industry – using expertise from this department and other national research partners.

We provide independent scientific research with a focus on warm-season turf grasses to meet the needs of the turf sector in Queensland, Australia and the wider Asia-Pacific region.

We support development and innovation across the whole turf industry by providing scientifically-based information to:

• turf producers
• professional turf managers of parks, golf courses, bowling greens and sporting fields
• facility managers
• homeowners.

Location

Research in Queensland is primarily conducted at Redlands Research Facility, 20 kilometres from Brisbane’s central business district. Redlands Research Facility has a subtropical environment, two contrasting soil types and access to dam and recycled water. This provides an excellent subtropical base for research into warm-season turf grasses. On-site research is complemented by test sites around Australia, maintained by our research partners.

Resources

Our research resources include:

• skilled scientists and technical staff
• a turf research laboratory
• tunnel houses and glasshouse facilities
• turf grass field plots, multiplication areas and a living turf grass library
• erosion conrol demonstration facility.

Living turf grass library

We have assembled an in-ground collection of more than 130 warm-season turf grass varieties, the most comprehensive collection of its kind in the world. Already, these grasses include a number of species not previously represented internationally in any other turf program.

As well as its educational value, the library serves as the basic resource for the group’s research program aiding research into:

• water use and bioremediation
• stress tolerance (salt, shade and temperature)
• diseases
• nutrition
• weed control
• characterisation and improvement of sports’ surfaces
• DNA fingerprinting
• breeding.

Erosion Control Demonstration Facility

A large scale erosion control education and demonstration site has been estalished at Redlands Research Facility. The project aims to educate decision makers and specifiers in the construction industry, as well as local and state government representatives from departments of environment and main roads from around Australia. The site demonstrates best practice in the use of turf as an erosion control measure. A series of thirty workshops will be conducted over the course of the project, which will also develop educational materials such as factshees, best practice guides and and training videos.

Greens testing facility

Redlands Research Facility was home to a purpose-built experimental green to evaluate new turf grass cultivars for bowling and putting greens. This facility was aligned to a commercial assessment program and will accelerate the introduction of new cultivars by bowling clubs and golf courses.

Find out more about new warm-season turf grasses for high quality greens.

Further information

• Broadley, RH 1978, The lawn armyworm, a serious rural and urban pest, ‘Queensland Agricultural Journal’, 104, pp. 232-235
• ‘Crop insects: the ute guide northern grain belt
• Bailey, PT (ed.) ‘Pests of field crops and pastures: identification and control’

General information

Most Queenslanders have heard of the smut disease affecting sugar cane in the Bundaberg area. A much smaller grass, green couch (Cynodon dactylon), is susceptible to its own flower smut. Couch smut (Ustilago cynodontis) was first recorded in New South Wales in 1907 and is prevalent throughout the mainland states of Australia. In most circumstances, it is no more than an annoyance to home gardeners. However, the disease can become a more severe problem and, like the related sugar cane smut, it is difficult to control once established.

Couch smut has been found to exclusively affect grasses in the genus Cynodon and is most commonly seen in green couch (also known as Bermuda grass). Although blue couch is similar in some ways to green couch, it is a completely different species from a different genus (Digitaria) and is not susceptible to couch smut. So if you think you might have couch smut, you should first take a close look at the grass species present in your lawn.

For more than 30 years, Tifgreen and Tifdwarf were the only greens-quality turfgrass varieties available. Now, the choice for golf courses and bowls clubs in northern Australia is being expanded by six new Cynodon hybrid and seashore paspalum cultivars.

The new cultivars differ from Tifgreen and Tifdwarf in their response to mowing, fertilising and other factors. They have a finer, denser and lower growing habit than previous greens varieties, allowing very low mowing heights to be imposed. This can result in denser, smoother and faster putting and bowls surfaces under optimum management, but they can also require more intensive dethatching.

Researchers are working on a project to identify the best management practices for high-quality playing surfaces and the geographic adaptation of these new grasses.

Details

Further information

Roche M, et al 2010, Management guidelines for New Warm-Season Grasses in Australia, HAL Project TU05001, Horticulture Australia Limited, Sydney, pp.167. Full report available from AGCSA technical research under Queensland Government, Department of Employment, Economic Development and Innovation.

Regular newsletters and trial updates have been produced since 2006. They can be accessed from AGCSA technical research under Queensland Government, Department of Employment, Economic Development and Innovation.

Roche M, 2010, Warm-season greens grass trial – Environmental and management guidelines suited for new and old cultivars, Proceedings 26th Australian Turfgrass Conference, Gold Coast, 24 June, pp: 87-97.

Roche M, 2010, ‘Warm-season greens grass trial – Environmental and management guidelines suited for new and old cultivars‘, 26th Australian Turfgrass Conference, Gold Coast, 24 June, webcast.

*A indicates varieties that are protected under the Plant Breeder’s Rights Act 1994 (PBR). Unauthorised sale or propagation of these varieties is an infringement under the Act. See IP Australia for detailed information and legislation on Plant Breeder’s Rights.

Summary

Fertiliser maintenance programs in public parkland tend to be driven by budgetary constraints rather than by plant needs. As a result, they can be ad hoc or virtually non-existent.

For turf, as with any grass, the main nutritional requirement is nitrogen (N). However, not all grasses are created equal when it comes to nitrogen. For example, blue couch will persist better than green couch under low soil nitrogen.

Experiments have determined the optimum nitrogen requirements for the maintenance of warm-season turfgrasses in Southeast Queensland.

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