Managing turf irrigation

By John Collins

electro-mechanical controls

Sports turf irrigation is becoming increasingly sophisticated with the help of advanced technology that enables minute-by-minute system control and complete customization of irrigation systems to create flexible and responsible water management.
Turf management has advanced beyond simply tracking weather patterns and the cycles of grass dormancy, vigorous growth and stress periods that correlate with changing seasons. Thanks to smartphone connectivity, turf managers have the power to literally control the irrigation system at their fingertips.
Older electro-mechanical controls had no program flexibility, but newer digital units are highly customizable to meet a variety of water needs or to fit water conservation guidelines. Today’s controllers enable the user to separate certain areas of the landscape, from the playing field to the sidelines, and deploy different watering levels for each. This flexibility ensures that each area is watered to optimal levels, while conserving water where possible.
Larger, more advanced systems use satellite weather data to provide the user with daily evapotranspiration values to better manage water use. These smart controllers take into account local weather conditions, whether it’s cloudy or sunny, lightly sprinkling or soaking rain, and automatically adjust irrigation schedules to prevent over or under-watering.
Systems also can be set up to monitor the amount of moisture in the soil. A probe measures moisture at the root, compares the reading to optimal conditions for the turf and soil type among other preprogrammed variables. It then responds accordingly by overriding the system if the soil is too wet or allowing it to operate as programmed if dry conditions are detected.
Additionally, real-time updates are available through Ethernet or smartphone applications. Human-machine interface displays and advanced controls can make a turf manager’s day easier by providing immediate feedback and authorizing supervision when they are away from the facility. Turf managers can customize a system to compile reports on usage, alarms and system history, valuable information in fine-tuning a system to optimize efficiency.
One of the advantages of an Ethernet network is its versatility. Any two machines on the network can potentially talk to one another. The networks are also infinitely extendable through the Internet. This means that if a machine is on a network that has access to the Internet, it can be accessed by other authorized users who also have Internet access. This connectivity is important for pump station communications and requirements. To view the data on a pump station from any location, both locations must have access to the same network, either directly or through the Internet.

Better pumps

For irrigation systems that include pump stations, technology has also helped improve pump performance. New software programs comprehensively manage power and efficiency with the use of variable frequency drives (VFDs). Advanced software improves system efficiency with simple touch-screen controls and highly accurate flow-meter technology.
VFD technology enables the control of the AC motor speed and torque by varying the input frequency and voltage to match the system demands. As demand increases, the VFD speeds up to match the needs of the irrigation system, controlling flow, which improves efficiency. For example, Xylem’s Flowtronex branded Pace Integrated Pump Controller uses advanced VFD control logic by operating the pump at the best overall efficiency, thereby reducing overall energy consumption.
These pump software programs and better integration with irrigation controls can make today’s pump stations up to 30 percent more efficient than those previously on the market.

Conservation measures

In addition to flow and moisture sensors to better manage how much water is used, an increased focus on water conservation is creating demand for water reuse systems. For example, at Levi’s Stadium in Santa Clara, CA the irrigation system is connected to the city’s recycled water system for playing field irrigation as well as irrigation of the stadium’s 27,000-square-foot green roof. About 85% of all water used in the LEED Gold-rated stadium is recycled water.
Salts such as calcium, potassium magnesium and sulfate and sodium chloride have an osmotic effect on roots and also affect soil permeability. If too much salt accumulates in the root zone, turf managers might be forced to change turf species. Salt can also harm trees and other plants. As interest grows in using recycled water for turf irrigation, turf managers must be sensitive to higher salt content that can occur from municipal water treatment processes or treated commercial effluent. Reverse osmosis (RO) systems are effective at removing salts and many dissolved organics from water as they pass through a semipermeable membrane. RO systems offer a convenient and cost-friendly method of filtering out unwanted contaminants in water that comes from both natural bodies of water and through recycled processes.
As turf managers struggle with diminishing water quality and availability, particularly in drought-ridden areas of the United States, along with rising energy costs and pressures to increase productivity, there are a number of technologically advanced resource management tools — from VFD-driven pumps to intuitive controls and filtering systems — that can help level the playing field and contribute to water savings.
John Collins is the global product manager-booster packages at Xylem Applied Water Systems. He holds a Bachelor of Science degree in construction management from Washington State University.

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