Irrigation Information

The irrigation system at MGC is the largest single piece of equipment that we own as well as the most expensive. Our system is not the most up to date or the most powerful but it is still capable of keeping the short turf playing surfaces irrigated. The decision falls on my shoulders on a daily basis to determine how much water and on what areas of the course the irrigation water should be applied. The first calculation to look at is ET (Evapotranspiration) which is the loss of water from the turf surface through a combined process of plant transpiration and soil evaporation. Days that are comfortable to golfers with sunny skies and low humidity are the days with the highest ET rate thus more water needs to be applied to the turf that night replacing the amount that was lost. During periods of high humidity less water is lost through ET thus requiring less irrigation. The over watering of turf is the leading factor in turf stress and disease outbreaks. If we think back to last year while I was not over watering mother nature was and the results showed the widespread death that can occur from excess moisture. The second tool that I use is a TDR 300 moisture meter from Spectrum Technologies that shows the VMC, volumetric water content, in numeric form. I use this tool every afternoon to determine how much moisture the greens have, providing me with information on how long to run the irrigation cycles. Many afternoons the TDR 300 shows that only a few small spots on certain greens require water which is added by hand with a hose. These spots are called LDS, localized dry spots, which are created by hydrophobic soil conditions. Wetting agents are applied on a 21 days schedule to help alleviate these spots and allow the entire green to have a more uniform moisture throughout the entire soil profile. The use of a hose to only water these select spots versus using the overhead sprinklers is important for root development. Again thinking back to last year the ground was always saturated thus the roots never grew to look for water as it was always present at the surface. Short roots in the spring results in no roots in the summer. My goal is to irrigate deep and infrequent to allow the roots to increase in mass and length during the spring allowing for a stronger plant in the summer. The other major issue facing us is that our well water is very high and sodium and bicarbonates. Each and every time I irrigate the golf course I am adding sodium and bicarbonates as is evident on the parking lot and cart paths where the over spray of irrigation water turns the asphalt white. The same thing is happening in the soil forming a crust that restricts the turfs ability to exchange oxygen and metabolize nutrients into the soil. The bicarbonates make the calcium and magnesium in the soil unavailable to the plant. The increase in sodium from the irrigation water destroys soil structure and reduces the percolation rate. In conclusion water management is one of the most important jobs that I have at MGC and by no means is the irrigation system set to water every other day or every third day for the entire season like many homeowners set their lawn sprinklers. Water is much more important when growing agrostis palustris and poa annua mowed at .120 of an inch then it is when your maintaining your home lawn at 2.5 inches.