Watering a golf course is essential for healthy turf and high quality playing conditions. Every living organism, whether large or small, needs water in order to survive. Turf grass is not an exception to this rule. One of the toughest challenges facing Golf Course Superintendents on a daily basis is trying to figure out how much water was lost, on any given day, due to a process called evapor-transpiration.

Evapor-transpiration is the word evaporation and transpiration combined, because between the two they are responsible for any moisture lost on a given day. Transpiration is a process in which the turf grass protects itself from overheating by releasing moisture stored from within it, in order to keep itself cool. We, as people, call this perspiration. The turf grass receives this moisture from the soil through its root system. Evaporation is the loss of moisture into the air from soil, plants, people, animals, ponds, lakes, oceans, etc., due to the humidity level, temperature and air movement.

The main source of adding moisture back into the soil, besides Mother Nature’s rainfall, is the golf course’s irrigation system. The irrigation systems nowadays are a maze of pipes and wires that run underground throughout the entire golf course property. Heads are spaced according to their ability to throw water a certain number of feet in a complete circle. There are many factors involved with the decision making process as to how much water should be replaced at the end of the day. Weather reports on temperature, humidity, wind and rainfall are monitored constantly in order to maintain the appropriate soil moisture to produce healthy turf and consistent playing conditions.

A few examples of this are, if you have a day that has a temperature of 80 degrees, a humidity level of 40% and a light breeze, your evapor-transpiration rate becomes extremely high. The turf grass has to use a lot of its own water to ensure its survival and keep itself cool. Therefore more water has to be replaced at the end of the day to replace what has been lost. On the other hand, if you have the same day, but change the humidity level to 100%, you would not have to replace as much water, due to the high amount of free moisture already in the air

Along with the reports we receive from weather stations, we also keep site specific weather reports. Thermometers, wind direction indicators and rain gauges are located in several areas on many golf course properties. The job of adding water to a golf course is actually an art that is very difficult to control or perfect. It is a requirement of all Turf Grass Professionals, to monitor soil moisture and weather conditions on an hourly basis. If our guard is let down for any length of time, the consequences could be disastrous and job threatening. Hopefully after reading this brief insight into part of a Golf Course Superintendent’s daily routine you will have a little better understanding as to why you see the irrigation sprinklers running on any given day. We do it so that the people who visit our facilities have the best possible conditions to play on everyday, and water is a necessary source to creating them.