Q: Why aerate?
A: Oxygen is essential for healthy soil and plant growth. It needs to achieve the right balance with moisture and nutrients. Heavily used or poorly-maintained turf will have reduced oxygen levels, along with the associated complications of compaction and impeded drainage. Nutrient availability and uptake will also be affected. The answer is to put oxygen into the soil by relieving compaction and re-establishing aeration channels. This can be achieved by making a series of slits or holes in the ground, or by removing cores from the upper layers of the soil. Removing cores allows soil exchange to be undertaken by introducing new materials.
Q: What equipment is best?
A: Choice of equipment will depend on the size of the area, the extent of compaction, the frequency of aeration and the aim of the operation. Hand tools are available for tiny areas of turf. Pedestrian equipment is useful on larger areas such as bowling greens and tennis courts or where access is restricted. Tractor-mounted and trailed equipment will be more efficient in larger areas and where time is of the essence.
Q: What action is best?
AThe drum or rotary type is the fastest working of the three main types of action and is particularly useful for frequent aeration, as a back-up to deep aeration practices or as a quick-fix on large areas. A range of heavy-duty rotary-action equipment with knives is also available, working on a vibrating principle to "shake" the ground.
The second main type is vertical action. This is where the aerator punches the surface. It is slower but provides good penetration when fitted with either solid or hollow tines, and can be deep. Vertical action machines also give effective treatment at closer spacing.
The third type involves the injection of air or water under high pressure.
Q: Which tines should be selected?
A: Different types of tine will give different results. Hollow coring tines are generally used to enable soil exchange and improve the rootzone through topdressing incorporation, as well as relieving compaction.
Hollow coring is a slow and arduous task, and consideration needs to be given to core collection or re-introduction. Where the ground is hard, it is best to use solid tines because penetration is easier.
Size of tine is also important. Smaller tines are generally used on greens. Needle tines can be used on fine turf without disrupting play. Chisel tines prune the roots to promote a thicker sward while aerating the soil - but note these tines should never be used on clay soils because they can result in the opening up of slits and fissures.
Of course, these are only guidelines - there is no substitute for experience - but it is important in all cases to check out the methods for swapping tines and the ease of adjustment for depth control.
Q: How important are training and after sales services?
A: Most people will judge a potential purchase on its suitability, efficiency and price. The other important criterion, and one often overlooked, is the quality of the after-sales service - especially machine installation. Wiedenmann UK area sales manager Chas Ayres has visited customers and dealers across the country and says when he is demonstrating kit he tries to establish what the customer wants the new aerator to achieve in terms of depth, speed and tine size, but he also emphasises the importance of after-sales attention.
"I can't emphasise how important it is to have someone spend time installing your machine with you when handing it over," he says. "Other key considerations are operator training and technical support. There is nothing quite like a new piece of kit to motivate the grounds-care team, but nothing demoralises them faster than not knowing how to use it.
"An induction session will help maximise the machine's efficiency and capability and leave operators confident and raring to go. They should also be shown what daily maintenance is required."
Q: What's new in kit?
A: The Arrow, from Sisis, is an independently powered, vertical-action, pedestrian-operated aerator with a 60cm working width and features variable tine spacing and independent disengagement of the tine drive.
A time-saving roller has been added to the pedestrian ProCore 648 greens aerator from Toro. It is intended to roll and smooth after solid tining, providing a surface ready for immediate play.
New from Ransomes Jacobsen, the Jacobsen Performaire 60 and 80 are tractor-mounted aerators designed to aerate to depths of 400mm. They have 1.5m and 2m working widths, operate at speeds of up to 2.25km/h and are primarily for golf fairways, but model 60 has close spacing for use on greens.
Toro has replaced its 660 and 880 ProCores with the new 864 and 1298. These have increased working widths of 1.63m and 2.49m. Maximum depth is 125mm.