Best Technical Merit Award Answers- September 2003
Following the success of the Technical Merit Award 2003, sponsored by Tillers Turf. Pitchcare have been publishing some of the best answers submitted to the monthly scenario questions. Following a two month break we are resuming with the best of the September answers. Next week the best answers to the October scenario question will be shown.
Also at the bottom of the Technical Merit Answer, please take a look at some photographs taken by Daniel Adams, Course Manager at Stafford Castle Golf Club of his rally day. Daniel won the day, having taken part in the Technical Merit Award. He said " I won the technical merit award over 1 year ago and chose to do the rally driving, it was a brilliant day and a great experience, thank you again."
September Scenario question
Explain the benefits of all year round aeration including the implementation of the various techniques available to the modern Groundsman and Greenkeeper.
Answer 1) Aeration is one of the most important operations done on the golf course. Aeration is done in a number of ways which all have different benefits. By using deep aeration like verti-draining or the new earthquake you can relieve compaction. The verti-drainer has large tines and flick up when in the ground which crack up compacted soil; the earth-quake put slits in the ground but also shacks which again cracks the compacted soil.
By relieving compaction you are improving drainage and also allowing roots to grow deeper which in turn help fight drought. By allowing air into the soil you are helping to break down thatch by oxidation and also builds up a health soil micro-life, which means you encourage health bacteria to grow which helps to fight disease. Hollow tining allows you to top-dress with out layering the soils which means roots will not snap at certain levels where top dressing change (layers)By scarification or use of the Graden removes thatch from the top layer, which will allow water to penetrate to surface easier and be absorbed by the roots. This also improves the playing surface as it allows the grass to grow a thicker sward. By deep aeration allows feed and fungicides to get deep into the ground like when spraying for fairy ring and the fungicide needs to get deep into the ground to be most effective. Aeration can be used to relieve black layer by allowing air to move around the soil and killing the toxic layer.Answer 2) Aeration is the second most important turf management practice after mowing, and is vital in sustaining a quality, hardwearing sward. Aeration is the mechanical introduction of air into a rootzone to improve the balance of air and water, whilst releasing toxic gases.
All cells contained within plants, respire, requiring a steady supply of oxygen for essential life processes. Leaves and stems can receive their oxygen from the atmosphere through the stomata, but roots have to obtain their supply from the soil.
Roots and aerobic organisms benefit from regular aeration, because of increased gaseous exchange; oxygen is supplied, but harmful gases removed from the soil. These gases include, carbon dioxide, and hydrogen sulphide (responsible for black layer), which is a product of anaerobic respiration. Aeration can remove these toxic gases and improve growing conditions.
Year round aeration ensures that roots and soil organisms are always receiving sufficient oxygen to respire, and is therefore fundamental to the growth and development of healthy root systems.
Cricket: Cricket squares are the main fine turf surfaces that can be aerated too much, or with the wrong type of aeration, and become inconsistent. Sarrel rolling cricket squares does not produce this undesirable result and should be considered as the main method for year round aeration on squares. During the summer months, sarrel rolling before watering wickets allows for the increased infiltration of water before rolling; this is necessary for the production of hard wickets. After play it can be used to 'key in' seed and fertilizers, and help to kick start the rewetting process.
During the winter months the sarrel roller can be employed on squares to keep the top open, reducing the occurrence of moss, algae and disease. If there are any major problems with the square other methods of aeration, such as verti-draining and hollow coring can be employed to alleviate the problem, but I would not consider these as a routine maintenance operation.
Golf: Greens, and putting lawns have a different requirement to aeration practice compared to cricket. Golf surfaces have no end of season renovations, and use different grass species. Year round aeration techniques have to comply with the requirements of golf, whilst also alleviating the problems associated with year round play, and thatch/fibre accumulation. During the spring and summer months the development of an increased thatch layer on golf greens can cause the surface to become hydrophobic, and therefore resist the penetration of water. A program of solid tine aeration and sarrel rolling on such surfaces during the summer months creates passages for water to penetrate the thatch layer and allow for deeper irrigation. The increase in oxygen into the thatch layer will also assist with its breakdown, and subsequently control its development. Thatch is broken down at better rates when the soil is warm, well aerated and moist.
Year round aeration, particularly in the early and late summer months can encourage increased thatch breakdown by increased moisture and oxygen inputs into the soil. If the area is irrigated regularly, as with golf greens it will be possible to reduce the thatch layer by aeration all summer, as the moisture is present. Slit tine aeration is very good at root pruning, without causing any disruption to play. The adventitious roots of Bents and Fescues used in golf have a tendency to grow near the surface of the rootzone, and if limited irrigation water is applied, cause shallow rooting. Root pruning during the autumn and winter months prunes lateral roots encouraging roots to grow downwards, thus reducing the fibre layer, and improving infiltration rates. Deeper root systems have less dependency on irrigation as they have access to more potential water during the summer months.
Hollow coring is another important type of tine used for golf, with the added disadvantage that it disrupts play. Hollow coring is considered by me to be a remedial practice to alleviate thatch and compaction and introduce desired swards and topdressings into the surface. Provided that aeration is practiced year round the use of hollow coring can be reduced, as the problems do not exist.
Football/ rugby: These surfaces are again different to cricket and golf, but still require a year round maintenance program. At the end of season renovations, serious consideration has to be made to restore the surface before the start of the next season. These surfaces are used in sometimes very adverse conditions, resulting in decreased sward cover and increased compaction. There are many options to resolve these problems, such as the use of spoon tines or hollow cores, to remove soil cores for re-dispersal, creating a tilth for seed to germinate, whilst also relieving compaction.
Hollow coring is the most effective type of aeration, as it removes a core of soil rather than pushing it to the sides and base. Hollow coring can be used at times of the year when seed germination is possible. Hollow coring is also ideal for removing deep thatch and replacing poor rootzones with better ones. Hollow coring however, is considered to be seasonal practice, and not carried out routinely unlike other types of aeration. Verti-draining and topdressing is also another option.
During the summer months these surfaces can become quite hard and resist tine penetration, however some aerators are ideal in these conditions. "Earthquake" machines work by cutting slits into the ground at regular spacings. If the soil is too damp the machine will smear the sides of the slit resisting root penetration, but done when the soil is dry will create passages that will not open greatly (as the soil has already shrunk), but be present when play is resumed and weather conditions deteriate.
During the autumn and winter months slit tines are the most efficient types of tines used for aeration. The tines will produce a slit hole that creates the greatest surface area for gaseous exchange within the root zone that also causes root pruning, and increases infiltration rates. This type of tine is best used in the autumn on any turf, as the slits have time to heal before the soil shrinks during the summer months, and cracks develop. Slit tine aeration on heavy soils with no irrigation is fatal after Christmas, in my experience. After Christmas, solid tines would be the most suitable for turf surfaces, to keep the top open and the surface drier.
Verti-drains or similar can be used, but tend to be slow especially if there are many pitches to do regularly. A drum spiker with solid tines is my preferred type of machine to use at this time of year, because it's reasonably fast and the ground is relatively soft enough to take a tine with limited pressure applied. There are many other machines available for aeration, whether pedestrian or tractor mounted, that work with hollow, slit or solid tines, with some machines taking the concept further and modifying their machines to further exploit the action of particular tines.
An example of such machines is the "rota knife" that cuts a long slit into the ground with a similar but more intense action as a slit tine. Verti-drains improve the action of solid and hollow tines to make their action more effective. Aeration is not to be a seasonal operation but a year round one. Modern developments and innovations in aeration machinery have made it easier for turf managers to find the right equipment for the right situation, at the right time of year.
Thanks to the innovations in modern machinery, Aeration can be achieved year round, and should be.
Rally Driving experience, pictures courtesy of Daniel Adams
|Daniel Adams ready for action||Getting used to the car||Now let's see what this baby can do|
|Yeeehaaaaa||Eat my dust boys||No I'm not pulling in to the pitstop!|