For most we have had an interesting start to the season going from a wet and cold period to a very dry period within four weeks. The combination of drying winds, high temperatures and little or no rain all for the whole of April has affected many greens, particularly if they have limited watering facilities.
If soil profiles, particularly sandy soils are allowed to dry out too much they often become water repellent (Hydrophobic) a state when soils can become difficult to re-wet. Often the first areas to suffer on greens particularly crown greens are the high spots on the green. You may need to spend more time hand watering these problem areas.
However, the long term affect of drying greens could be detrimental to surface playability. The surface could begin to break up, particularly on sand predominant greens. Sand becomes unstable when in a dry state and the surface can become bumpy. Different grass species will respond differently under drought conditions, growth rates will vary depending on habit and root structure, thus promoting an uneven surface. Once the soil goes beyond a certain drying stage you are likely to encounter dry patch symptoms, whereby the soil becomes hydrophobic, being unable to absorb water. The water simply runs off instead of soaking into the soil profile.
Water will also always wash off from the high spots into the low areas, so the low spots tend to remain green and lush. This variation of dry and wet areas will affect surface playability, the bowls will fly across the dry areas and slow down on the lush green areas.
Once soils become hydrophobic they can deny adequate water movement to other areas of the root zone - often resulting in water deficit stress with symptoms that include a general decline in the biological health of the plant which in turn effects shoot and root growth.
You may need to consider using wetting agents to aid recovery or help prevent these problems occurring in the first place. Many green keepers now utilise wetting agents on a monthly basis to keep the root zone in good condition.
The movement of nutrients in the soil is also dependant on the moisture state of the soil; dry root zones will slow down or even prevent nutrients being assessable for the plant. Which again will result in plant health decline.
If you do not have adequate watering facilities it may be beneficial to raise the height of cut by 1 mm to keep a bit more grass on the green during these dry periods. It may slow the game down a bit but will help sustain your green through these difficult times.
It is important to water correctly, under or over watering will have a detrimental affect to plant health. You need only to apply enough water to replace what has been lost by evapotranspiration. Depending on the aspect of your green ,soil type and herbage cover you could be losing anything between 3-5 mm of water per day. This will need to be replaced by watering .
It is important to ensure you water evenly and to depth , you want to ensure the water gets down beyond the rooting profile at least between 100-150 mm. This will encourage deeper rooting as the green dries and the roots go in search of the descending water..
Also check your water quality, what pH is it ? is it suitable for your green? Check filters on recycled water systems. Poor water quality will affect plant growth and sustainability.
Most greenstaff will have already applied a spring/summer fertiliser, perhaps something like a 9/7/7 and will be looking to apply a summer fertiliser, reducing the N and P inputs to maintain a balanced growth during May. At the end of the month an application of a slow release fertiliser will see you through June and July.
Regular brushing and sweeping are important tasks to keep the surface clean, open and dry. A dry surface will aid resistance to disease. Keep an eye on fungal disease attack and use approved fungicides to treat infected areas.
The sward will be actively growing due to the increased soil temperatures, coupled with the stimulation of fertiliser applications. Regular mowing will be required to maintain sward height at around 4-5mm. Verticutting/grooming fortnightly can be carried out to help speed up the green and help improve the health of your turf.
With the development of mowing technology, most fine turf mowers have cassette fitting attachments that offer additional maintenance operations such as grooming and verticutting. These are both operations that effectively remove thatch and side shoot growth enabling the promotion of an upright plant and denser turf growth.
Aerating with micro tines or sarrell rollers helps keep the surface open, allowing gaseous exchange and good surface drainage.
Some clubs now use turf irons (rollers) to prepare surfaces for play, these are specially designed ride on turf rollers that apply even pressure over the surface. However, rolling can have a detrimental affect on your turf if done at the wrong time or too often. There will be a need to increase the frequency of aeration techniques to counter balance the practice of rolling.
Seeding sparse or bare areas can be continued. Any rise in soil or air temperatures will help germination. Use germination sheets to aid this process but remove the sheets regularly to check for diseases. Remember that without good seed to soil contact the operation is useless. Ensure you use new seed as old material may not give you the required germination rates.
Irrigation systems need to be checked, inspect installations for leaks and check that the sprinklers work. There will be a need to irrigate during May as air temperatures rise and daylight hours are getting longer, increasing the likelihood of the ground and surfaces drying out.
It is always important to keep a diary of what work you have carried out, stating times of operations and amounts of materials used. Also, keep weather records. This information can be very useful in the future, especially if problems arise.
There are a number of performance quality standards (BS7370:P3, A6 standards) that can be used to measure the condition of your green. These include the measurement of:-
The results are measured against predetermined standards (high, standard and basic levels). These can be seen in the Performance Quality standards (part one, sports surfaces natural/non turf). These standards can be used as a bench mark for you to aspire to and maintain.