SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/32290
FieldScience water has a very strong bond to itself. In addition, the smaller the particles in the soil the more attractive the water to soil bonds are. That is why soils with high organic matter contents have a larger affinity for water than soils with limited organic matter as OM con- sists of smaller particles than anything else that makes up the physical structure of soil. Finally, water in the upper profile and its movement depends on the amount of moisture in the lower profile. If water is present up top but not down bottom, it will take cultural practices in most situ- ations to make a change as there is something holding that water up (OM, hard layer, sod layer, etc). Many of you use wetting agents when this is the case. We’ve learned from managers like you who have installed sensors to monitor water movement throughout the profile that all wetting agents are certainly not created equal (a topic for another article). On the flip side if we have a lot of water in the lower profile and not much in the upper, this is typically conducive for strong root growth assuming the water is not backed up due to a drain clog or there is no layer dividing the two regions. But what we have learned is that there most certainly is a region of moisture that is best for turf quality to be at its finest at the surface and it is typically when there is slightly moist to dry conditions in the upper two-thirds of the root system to slightly moist to moderately moist in the lower profile. In addition, the depth of measurement varies from site to site and can only be identified when the sensors are installed. Kenny Pauley maintains the football field at the University of Georgia and says, “UgMO has allowed me to understand what my optimum game day conditions are. I didn’t use the system to tell me what those conditions are…I prepared them and then used the meas- urements to know what the conditions are for my field. With that in- formation I can now understand days before a game, depending on the forecast and other influential events what I need to do to get those conditions back. Do I need to get water deep or shallow, un- covered or covered…whatever it takes to get the conditions I need for the best playability.” Pauley is expanding his use of the sensors throughout many areas of the campus as he is finding the information more and more useful. DODGER STADIUM In the early use of the system at Dodgers Stadium, Eric Hansen found that the park was not initially set up to monitor every gallon used on the field since much of the water was shared outside of the stadium and other areas. Interestingly, the goals of Eric are similar to that of the others…they are managing for the best playability. While saving water is important, they are not operating to save water but simply to use it most efficiently to manage the property in the envi- ronmentally conscious way while providing the conditions necessary for the game. I worked closely with Eric to achieve his goal of finding how low he can actually go on his moisture levels before he had too little water in the soil. He learned that there is a limit. More impor- tantly he learned that reaching that limit is not a good idea but main- taining at a level slightly above it is wonderful. As a result of crossing the limit, his bermudagrass was set back and took a lot of attention, time and water to bring back. Other areas that were maintained at or above that threshold held up quite well throughout the season. What all of the users of UgMO’s soil monitoring system will tell you is in agreement with our agronomic philosophy…that is, UgMO doesn’t tell you what to do. While even with the ProHome system mentioned above where it makes irrigation decisions daily based on changing soil conditions, even that system has intelligence in it that is science based with regard to how water moves through each and every soil…and how every soil is truly different. But for turf managers, particularly in sports where the camaraderie is strong, sharing information seems limitless and without hesitation. Learning from each other and seeking every piece of knowledge that can help make better decisions is more of a reality than ever with the ability to see wirelessly into the soil whenever or wherever one wants to. In the chart on page 14, notice the upper moisture (red) dried down significantly to a point the mimicked a large decline in mois- ture in the lower profile. In this situation which is the opposite of what is best for strong plant growth, it becomes very difficult to re- wet the entire profile and get the conditions conducive for high sur- face performance. The green band called the UgMO Zone on the user interface which is accessible from any internet connection indi- cates the target moisture level. This level is user defined and identi- fied through the experience of the field manager and the association of recorded values with condition observations. Managing moisture to these targets allows for consistent conditions, a reduction in over- use of water and the predictability of how the turf will perform on game day. ■ 16 SportsTurf | June 2011 www.sportsturfonline.com