Recording the Weather
By Gordon Jaaback
All golfers are becoming more aware of the weather. It affects their attitude to play as well as the flight and roll of the golf ball. For greenkeepers however, their entire work pattern is dependent on the weather.
Recorded weather measurements are a back-up to all work on the golf course, giving supporting information that gives reason to success or failure of individual treatments. All treatments are dependent on the weather conditions at the time, and tabulated weather records serve as a cross reference in producing a complete picture - one where judgement leading to ensuing action is sound. Furthermore, keeping abreast with the changing pattern of weather is invaluable in forecasting the onset of disease, and modern computer software can offer this function. This tool, combined with the current cost of chemicals, can initiate the appropriate cultural treatment that brings significant savings.
Measuring the contents of a rain gauge and the maximum and minimum temperature overnight are no longer enough. Automated measurement at regular intervals with current software can give a profound illustration of changing trends in the weather. In addition, the equipment does not need to cost the earth. A variety of models are available from as little as £500, whilst sophisticated packages can reach £4,000. In an annual maintenance budget which may be in excess of £150,000, this one-off investment can be a cost-effective tool to sustain the higher standards demanded now and to increase levels in the future. In fact, the facility can virtually pay for itself in controlling and justifying expenditure on the course, and gives management the data it needs for financial reviews. The minimum outlay of £500 barely covers the cost of one fungicide spray.
Furthermore, the Club and its members can accumulate information that assists significantly in planning, and golfers can attain a better understanding of conditions on the course and why they have developed. Weather information can also be relayed to the Club's website.
Water Comes and Water Goes
Gentle but penetrating rain, though a nuisance to golfers, is of the most benefit. Drizzle offers little in actual precipitation and a thunderstorm can bring untold damage in minutes. When rain falls at a greater rate than the soil can absorb it, most of the water is lost in run-off to lower lying areas. Therefore, if the standard rain gauge measures the total rainfall over a period of 24 hours, this tells us little. A built-in tipping bucket mechanism that tips every time 2mm of rain falls, records the intervals between times when this occurs and so gives a record of the rate at which the rain has fallen. This gives an idea of the effectiveness of the rainfall, which is vital in planning on-going irrigation.
As there is only need for sufficient water to the depth of the roots to keep grass actively growing, it is logical that a water reservoir available to the grass plant is of value. Irrigating with fresh water can be very expensive with a cost in excess of £1 per cubic metre, and an accumulation of water in excess of the need not only becomes an unnecessary cost, but can lead to an unhealthy condition in the zone of root growth.
However, there is a daily water loss - officially termed evapotranspiration - from the actively growing plant. This is influenced mainly by the sunshine, temperature and wind. The loss is greatest in the hot months between May and August and is determined by most weather stations from the recording of these measurements. Knowing what amount is applied by irrigation, measured as effective rainfall, and lost by evapotranspiration gives us a simple means of understanding the water status in the soil at any one time. Awareness of this water balance for the well-being of the putting surface is similar to the importance of knowing your bank balance.
Failing to be aware of this vital balance during the hot months can easily result in an excessive build up of moisture in the root zone from watering to excess. Where the water penetration is not regularly checked, it can lead to the development of a powdery dry zone below the putting surface.
Temperature and Wind
Temperature, together with sun radiation, is second to water in importance. Unlike rain, which comes and goes in relatively short periods, temperature is generally sustained over a longer time span - and the temperature pattern is fairly consistent year in year out. In the case of cool weather, it is above and below the measurement of 8-10°C in the soil that radical changes take place. Below 8°C in the soil, there is no significant growth. Air temperatures have to reach 15°C for optimum growth while above 24°C there is a noticeable slow down. A recorded trend in temperature change therefore becomes a traffic light in planning vital treatments to the putting surface.
The changing weather on this small island is a product of ever-changing wind cycles. The rise and fall of the needle in the barometer indicates the pressure change, and it is high-and low-pressure systems that generally forecast sunshine or the nearness of rain and the consequent weather trend. Following its movement daily can therefore raise or lower the warning flag. Thunderstorms, of course, are a different matter coming as they do after days of heat and the build-up of localised ram clouds. This often accounts for significant variation in rainfall between one site and another.
Weather stations may not be accepted as an essential requirement for golf courses by some, but when seen in the context of the backup and support they offer in the management of a complex and high quality facility, they must become an economic consideration. Furthermore, the regularity of measurement will undoubtedly produce a pattern of historical data that becomes of immense value. In addition, when presented as a daily information bulletin it can be of immense interest to the golfer.