March 2008

Airing views on turf improvement

With the main growing season fast approaching, the optimum conditions needed to produce quality sports turf include good drainage to cope with heavy rainfall coupled with the soil structure to encourage plentiful gas exchange and a supply of nutrients to the roots.

Ideally the rooting zone should be 50% soil particles and 50% pores, of which the pore volume should be half filled with water and half with air.

Soil compaction compromises this balance and can hinder root development essential for a healthy sward.

Continuing wet weather in many parts of the country has led to waterlogged sports surfaces and a poor growing environment for turf. In turn the sward has reduced tolerance to wear and tear and struggles to recover after play. The pressure for sports surfaces to remain in play and look good all year only makes the groundsman’s task more difficult.

Equally, should the unpredictable British climate switch back to the drought conditions experienced in 2006, dry and hard surfaces could struggle to channel irrigation water down into the soil, resulting in runoff and wasted resources. In these conditions any fertiliser or pesticides applied may well be lost as they cannot penetrate the soil in order to take effect.

It is universally acknowledged that aeration improves drainage and improves the ability of soil to absorb irrigation water, but with the plethora of aeration machinery on the market and the variation in designs, it can be difficult to work out what to use, at what time of year and how frequently.

There are a lot of different machines available, Campey Turfcare’s Richard Campey agrees, but choosing the right system is key.
“It all depends on what effect you are looking for, and what type of surface is involved,” he explains. “Some groundsmen have strong feelings that you should not aerate at certain times of year or in particular conditions, but it is really a matter of finding a system to meet your needs.”

Large areas are a case in point, he suggests. “Often on racecourses or sports pitches, the priority is to get surface water away so that the turf can be used in wet conditions. But a high workrate is also needed, which could be costly in terms of wear and tear on smaller machinery and requires plenty of horsepower.”

Campey Turfcare has added the Carrier Turf to its range for this type of application.
“The Carrier Turf uses angled discs with knives to slit the turf and penetrate the thatch layer, and due to its inbuilt pressure weight transfer system, can work well in hard conditions,” Richard explains. “This machine can be used frequently, and it incorporates a brush system to stand the sward up plus a roller to level the surface, so the pitch or fairway can be quickly back in play.”

The slitting action, he points out, promotes root growth and consequently gives healthier turf. Users have also found that subsequent fertiliser application can be reduced, as nutrients are released from the thatch layer and from organic material. To suit applications ranging from football clubs to multi-pitch playing fields or racecourses, the Carrier Turf is available in 1.75m, 2m and 4.5m working widths.

Regular slitting can benefit all types of sports surfaces, and many contractors and local authorities need an implement that can tackle a range of jobs, Richard suggests.

“The Imants Rotoknife gives effective surface aeration at any time of year and can be done on a regular basis,” he says. “Using a combination of discs mounted on rotors within its frame, the Rotoknife can work on anything from golf greens and tees to sports pitches to break down thatch and get rid of surface water.”

As the discs can be interchanged without tools, the Rotoknife would be ideal for an operator working in a situation such as a municipal park, where several different surfaces require treatment, Richard comments. With a useful working width of 1.8m, power requirement is 50hp, an increasingly universal tractor size, and as it is a high speed operation, using the Rotoknife fits in well with busy schedules.

“Effective slitting results in a denser and healthier grass sward and helps to eliminate problems such as thatch, avoiding the need for time consuming scarification,” says Richard, “So it is well worth incorporating a machine such as the Rotoknife into your routine maintenance programme.”

For more intensive aeration, he recommends a rotary linear machine such as the Imants Shockwave, which uses long curved blades mounted on a rotor to fracture the soil.

Golf fairways and football and other sports pitches can effectively be treated with the Shockwave, says Richard.

“The Shockwave can relieve deep seated compaction to a depth of 35cm. It can be used from October to February, but only once or twice a year as it is much more intensive. It is also a slower operation, so timing needs to be carefully planned.”

The rotary action of the blades displaces the soil, and combined with the Shockwave’s forward speed, creates a wave action, shattering the soil laterally and decompacting thoroughly down to full depth without damaging the surface.

“Surface water is allowed to get through, and compaction is relieved by up to 50%,” says Richard.

Decompaction machines have to be tough, he points out, and the Shockwave has recently been upgraded with a central gear drive and a torque limiter on the pto to avoid costly downtime. Two models are available, 1.55m and 2.1m wide and with power requirement from 35 and 47hp respectively.

Seasonal renovation of sports turf in spring or autumn can also be a good opportunity to undertake an aeration programme. Richard explains: “It makes sense to combine operations and including aeration as part of the renovation package can give even better results from the new turf. The Koro Recycling Dresser can be used on golf courses, sports pitches, bowling greens and racecourses.”

Rotary blades crack the surface, bringing soil to the top for use as a top dressing. “This puts more oxygen below into the soil than any other machine on the market and the Koro Recycling Dresser can aerate to a depth of 15cm,” says Richard.

Continuing development has seen the Recycling Dresser made available in sizes from 1.3m for fine turf on golf and bowling greens, to full contractor capacity 2.5m versions. With no cores to collect and a smooth finish ready for overseeding, busy areas such as golf greens can soon be back in play.

An effective combination can be the Recycling Dresser with the Koro Field Top Maker to relieve deep compaction.
“Two sets of blades break up compacted soil to a depth of up to 20cm and then recycle material from below the surface as a fine top dressing, Richard explains. “This enhances drainage characteristics and leaves an excellent tilth ready for overseeding.”

“There’s an aeration solution for all types of sports turf,” comments Richard Campey, “And most can be specified in a size to suit even the smallest operation. It’s a matter of assessing the level of compaction and finding a machine that can relieve it. But prevention is better than cure, and aerating on a regular basis can make a major contribution to healthy, hardwearing turf.”