Under hot weather conditions, there is often a tendency to apply more, rather than less, water so as to be sure that drought stress does not occur. This can promote soft conditions and places additional stress on the turf. When turfgrass is over-watered, soil pore space that is normally filled with air is then filled with water, and root decline can occur due to a lack of oxygen. Roots do not grow deeper in search of water. By contrast, soils that have adequate moisture and oxygen levels promote deeper root development and more root mass. Water also conducts heat, dangerously increasing soil temperatures under hot, saturated conditions.
Fine turf performs better when efforts are made to promote and maintain drier conditions.
Ways to assess the watering needs for turfgrass vary from high tech computers and evapo-transpiration devices to simple visual assessments of the water and moisture status of both the turf and the soil by foot-printing techniques and through the visible wilting of grass leaves. If you simply step on the green or turf area being checked and the turf does not have enough moisture in the leaf for it to bounce back or recover, instead it leaves a stressed looking footprint on the turf, then the turf lacks water. Soil moisture should be checked with a soil probe to a 6-8 inch depth. By experience, the Golf Course Superintendent should identify these indicator sites where turfgrass water stress first occurs.
Application of water to a turf area should be determined by the Superintendent based on (a) environmental conditions such as rainfall, sunlight and / or cloudy or shaded conditions, (b) replacing water that was utilized by the turf in the root zone, and (c) watering in fertilizers and / or insecticides.
The appropriate level of water to apply should be equivalent to that removed from the soil since the last irrigation or rainfall. The actual amount of water applied also depends on the water retention characteristics of the soil.
When and how much to irrigate is one of the most difficult decisions in golf course turfgrass culture. Unfortunately, irrigation practices and systems are too often misunderstood and misused. Many golfers tend to rate the golf course conditions on how green and lush the turf is and a green colour is expected at all times. However, such a green turf is not the most healthy or playable.
Water is one of the planet's most precious resources. Both golfers and Club Management should make a concerted effort to learn how to understand and manage it for the greater good of all areas involved.