Unusual Turf Problems

Unique practices enable the Hong Kong Jockey Club to achieve world-class racing and training surfaces under extremely challenging conditions (first published in NZ Turf Management Journal, Winter 2014).

Happy Valley Racecourse

The facilities

In Hong Kong, we have two international standard racecourses – Sha Tin and Happy Valley. They both feature sand profile turf tracks. Sha Tin Racecourse has 2 All-Weather Tracks located inside the main turf track. Based on American dirt track designs, the larger is used for both training and racing, while the smaller one is used for slow training only.

Sub-tropical conditions

Temperature and light

Hong Kong’s climate is temperate for nearly half the year with mean monthly temperatures between 15.8 and 28.8ºC from November to April. In contrast, May to August is hot and humid with occasional showers and thunderstorms. Afternoon temperatures often exceed 31ºC and remain around 26ºC at night. There is usually a fine dry spell in July, which can last for 1-2 weeks or even longer.

Rainfall

The mean annual rainfall is 2,214 mm with 80% falling May-September. The wettest month is August when the average rainfall is 391mm and there’s usually rain 4 days out of every 7. The driest month is January, with a monthly average of 23.4mm and rain on only 6 days or so.

Dual turfgrass system

Under these conditions, there is no one type of grass that can actively grow year-round, while providing the aesthetics and recovery demanded by Hong Kong’s intense racing program. Consequently, a dual grass system is used.

Hybrid Bermudagrass provides the base crop and grows actively in the warmer months; it is oversown with Perennial Ryegrass from mid-October onwards. This mix provides the best possible racing surface (regarding cushioning, colour and recovery) until the end of April when the Perennial Ryegrass dies very quickly due to the rain and high humidity.

Other dual grass systems used elsewhere include Zoysiagrass and Tall Fescue in Japan, and Kikuyugrass and Perennial Ryegrass in the southern Australian states.

Sha Tin Racecourse

The Bermudagrass Challenge

Over the winter months of December-March, Bermudagrass has a dormant phase. Growth becomes slow and over-seeding with Perennial Ryegrass is essential to provide the recovery needed.

The low sunshine hours during spring and the warmer months also create problems. In light intensities lower than 70% full sunlight, Bermudagrass responds by developing narrow, elongated leaves, thin upright stems, elongated internodes, and weak rhizomes and stolons. It becomes very sparse and thin. It has poor recuperation under divoting and is prone to algae infection – a situation commonly found on intensely managed golf greens and sports grounds (McCarty 2002).

Summer root growth tends to be shallow and rhizomes are few, so the turf becomes less wear-tolerant and surface stability is significantly affected in a racetrack environment (Adams 1997).

Furthermore, the spring transition performance could be severely impeded by carbohydrate depletion from excessive vertical shoot growth under rainy or low light conditions in summer. This results in poor stolon and rhizome mass formation. These plant organs are vital during the resurgence of Bermudagrass during late spring (T. Field, pers.comm.).

Quite common in South East Asia, this problem has been described as a complex syndrome called “Bermudagrass decline” (Shepard et al. 2000). Bermudagrass used to work well when racing finished in May as the Perennial Ryegrass started to decline. Nowadays, with racing continuing into the rainy season, more proactive plans (via literature searches, trials and benchmarked practices) have been introduced to enhance the performance of the grass transition period. The alternative is a massive winter grass die off and bare ground, which is simply not acceptable.

Our transition management philosophy is based on how chemical energy in the Bermudagrass sward flows year-round and the interventions needed to facilitate these changes with Perennial Ryegrass as a temporary winter cover.

The use of a modern plant growth regulator was also introduced during our rainy offseason. Its purpose is to build up stronger plants by conserving energy at the cellular levels, producing better plant forms under shade before entering the cooler months.

A good illustration of surface water, poor visibility and rain-affected going over 30 years ago when a conventional soil profile was used. Surface changes and race cancellations were common and inevitable.

Poor transition performance in early 2000.

Financial imperatives

The financial cost of race cancellations is major in Hong Kong. Racing turnover has risen steadily for the last five seasons, with a total of 769 races staged each season on 2 courses. If races are run in very heavy and rain-affected track conditions, the drop in betting could be very significant. Furthermore, staging a replacement meeting is difficult as it involves decisions from numerous parties (the police, government, transport – train and bus companies).

Racing Turnover in Million NZ$

Management strategies

The Club pioneered the use of a reinforced USGA-style root-zone back in the late ‘80s to address the rain issue. Since then, the science and technology of sand construction have further developed to include:

  • Using a finer sand envelope with better surface stability.
  • Improving the precision of profile construction methodologies to ensure a desirable perching effect by avoiding particle migration. Achieving consistent moisture retention at the surface with the root-zone constructed to a set depth, and using moist sand for construction.
  • Using modern soil tests (e.g. moisture release curve, hydraulic conductivity, drop cone stability and sand gravel compatibility) in the selection and quality control of sand and gravel material.
  • Managing organic matter accumulation on a mature sand profile. Despite the selection of a USGA profile in the late ‘80s, coring programs were only introduced in the mid ‘90s to manage excessive organic matter at the surface (which caused deeper divots, surface water, firmer going and shallow roots).
    Deeper cultivation with hollow tines were initiated in late 2000s to mitigate organic migration down the root-zone, sub-surface compaction and to prevent black layer formation. Grass clippings are removed after each mowing to prevent accumulation at the surface. Aggressive scarification is implemented during the off season (to remove thatch), combined with sand top-dressing to manage the organic profile within an optimal level.
    It is management’s goal to extend the shelf life of the root-zone by proactively managing the physical properties, as total reconstruction is not an option given the Club’s racing program.
  • Implementing an aggressive nutrition program. In the late ‘90s, regular sand and tissue testing programs were implemented. These improved the understanding of the nutrient profile and the plants’ uptake so that data-based fertiliser programs could be designed with precision to prepare the sward with a good balance of shoot and root growth.

A recent illustration of the success of the root-zone management was when the Happy Valley track was raced on 22 May 2013, close to a “Dead Track”. By 9am, 201mm of rainfall had been recorded over the previous 24 hours, and then an additional 23.2mm was recorded on the day.

Track usage

Racing and turf trials are conducted from September to mid-July. Intensity and frequency of wear on the turf surface is heavy. Tracks cannot be prepared on the firm side to minimise wear, as adequate cushioning is essential to improve the horses’ racing careers. Therefore, a strong turf cover is essential:

  • To provide the best possible racing surface.
  • To survive the frequency and intensity of wear under tight racing programs.
  • To ensure rapid recovery after racing.

As such, it is critical the off-season renovation and racing season repair on the turf sward achieves the above objectives.

The racing season closes by mid-July to allow aggressive renovation of the dirt and turf surfaces. Given the current turf species, optimal maintenance, and nutrition regime, the success of our summer track renovation programme still largely depends on the prevailing weather conditions.

Turf track maintenance

Grass nurseries

Sods with different summer to winter grass ratios are produced to meet the divot repair needs under different climates.

Track position

Movable rails and posts are installed along the inside areas to define the racing area and protect the racing field. Rail allocations influence track-riding patterns, as they lead to different radii around the bends. Consequently, their movements are carefully planned one year ahead in collaboration with the race program development. This optimises recovery windows, improves wear management and assists trainers with their entries and preparation of horses.

It is our policy to move the rail after every race meeting to give the best possible turf surface for the next meeting. This also allows repairs and renovation works to proceed behind the rail. The true (inside) position is mostly allocated for the Group One races.

At both Hong Kong racecourses, we use aluminum rails so they give under impact, and cast iron padded posts to provide strong support and hold the rails in place at all times. Horses can’t be allowed to go through the rail, due to the large drainage system and access road just inside the rail area.

Adaptive renovation strategies

Renovation in the earlier days tended to be traumatic and was limited to the off-season, with a long recovery period. But since 1989/1990, the Club has increased the number of race days to meet customer demand and the gap between racing seasons is getting ever shorter.

To cope, renovations works are broken down, cascaded and spread out during the racing season. We alternate the tines diameter, grid pattern, number of cutting units and density to conduct renovation works regularly during the racing season, without affecting surface stability and grass cover quality.

Track assessment

To ensure the surfaces perform, the Club has introduced target performance standards for botanical characteristics, and chemical and physical properties. Regular testing and measurement (e.g. soil and tissue testing, hydraulic conductivity, nematode assay and surface hardness) are conducted to plot changes over time. Proactive action plans are implemented to mitigate performance deviations.

In addition to this internal process, an independent, overseas expert assesses track conditions and root-zone properties each year, benchmarking track performance to assist maintenance planning and the offseason renovation program.

This technical audit includes moisture release characteristics, drainage, hardness, organic matter profile, compaction, aeration content and botanical character. The expert also assists us in predicting the possible outcome of transition performance (from winter to summer grass) of various parts of the track by analysing core recovery.

Another major application of this audit is to help us manage and balance the organic profile at the optimal level for our root-zone. While organic matter contributes desirable cushioning, traction and agronomic benefit to the preparation of the racing surface, excessive accumulation will slow down drainage, deter deep rooting and create compaction related problems.

Summer Grass Nursery.

Watering the sand profile to condition the surface pre-race.

A massive Pythium outbreak in April 1997.

Track monitoring on race day

Going assessment

On top of maintenance-monitoring procedures, the track going is monitored on race days with a range of devices, including a Penetrometer, Shear Vane, Going Stick and a 2.25kg Clegg Hammer.

Moisture content

Cores samples are collected from every race meeting. From these, the moisture content at the surface is recorded so that pre-race watering can be adjusted in order to achieve consistent levels across all meetings, weather permitting.

Other measurements

Jockey opinions and the track speed are also recorded for referencing and monitoring purposes.

Plant protection

Common pest problems include caterpillar, grub, mites, mole cricket, earthworm and nematodes.

Common weeds include Cyperus and Sedges, Crabgrasses, Paspalums, Black Medic, Oxalis and Crowsfootgrass.  

Cuvularia and Helminthsporium are the key disease pathogens affecting our Hybrid Bermudagrass, while Rust and Pythium disease attacks our Perennial Ryegrass. In addition to the use of organic (e.g. tea sea powder for earthworm) and chemical treatments, it is critical to nurture a strong and healthy turf sward, with strong roots, in order to cope with such stresses.

We consider nematodes as the most critical pest as the chemical options for control are very restricted; and Pythium is the most deadly turf disease because it spreads very quickly. Both problems will affect the root system which is vital for surface stability and recovery.

People management

The success of our operation lies in how we recruit, groom and nurture our human capital. As agricultural industries don’t really exist in Hong Kong, locals begin careers in the landscape or sports turf trade.

There is no turf management discipline at the vocational or college level in Hong Kong, so the Club has developed extensive in-house training programmes to develop new recruits, technicians and workers. It finds talented college students through field days, college seminars and summer internships. Club Track Trainees then go through customised training programs, turf management training in the TAFE system, overseas track and field experience and conferences. This develops them to sustain a pool of talent to meet the Club’s long term business goals.

Building club capabilities

It has been extremely challenging to improve maintenance practices and surface performance in Hong Kong under tough climatic conditions, with the lack of local expertise and professional support, and high usages and demanding expectations.

The team has successfully adapted, addressing weaknesses with new and fact-based solutions across the whole operation. This achievement will be sustained and replicated in future by the development of a home-grown, talented team with international experience.

References

Field, T.R.O. (1994). Horse Race Tracks. In Adams, W.A & J.R. Gibbs. Natural Turf for Sport and Amenity: Science and Practice. CABI. pp. 329 to 353

Hong Kong Observatory website (www.weather.gov.hk)

McCarty, L.B. and G. Miller (2002). Managing Bermudagrass Turf: Selection, Construction, Cultural Practices and Pests. Wiley. 221 p

Shepard, D. DiPaola, J. (2000). Regulate Growth and Improve Turf Quality. Golf Course Management. March 2000: 56-59.

Pako Ip

Pako Ip

Executive Manager, Tracks

The Hong Kong Jockey Club