Effluent Water Influences Turfgrass Growth Compared to Potable Water

Grady L. Miller

Effluent and other secondary waters have become important sources of irrigation water in Florida. Information is inadequate relative to potential effluent irrigation effects on turfgrass rooting and leachate water. Effluent water typically contains elements such as N, P, K, and other essential plant nutrients. Along with beneficial nutrients, other potentially harmful elements may be present which can cause negative plant effects. Most of the research work published evaluated only the initial effects of effluent irrigation on soil, leachate, and shoot quality on grasses that would typically be found on golf courses. Little is known concerning rooting parameter differences due to application of effluent waters, especially with St. Augustinegrass. Since effluent use is becoming more common in residential areas, investigations with more traditional Florida lawn grasses are important to the understanding of how to best manage effluent water use.

...To evaluate water sources in this study, effluent water was collected from University of Florida Golf Course and Gainesville’s TREEO Center and potable water from the Turfgrass Envirotron tap. Grasses that water treatments were applied to included ‘FloraTex’ bermudagrass and ‘Floratam’ St. Augustinegrass grown in translucent lysimeters in an environmentally controlled glasshouse at the Turfgrass Envirotron.

...Turf quality ratings were taken beginning 13 September 1996 and continued until December. Initial quality ratings were fairly consistent across treatments. By week 3, Treeo Center water was performing the best and tap water performance was poor. Bermudagrass seemed to respond to UF effluent water more than St. Augustinegrass. Turfgrass quality was acceptable for all treatments during the duration of this study except for St. Augustinegrass grown using tap water (for a couple of weeks). Turf canopy density tended to increase with time despite poor turf quality. Bermudagrass samples generally had higher density compared to St. Augustinegrass samples. Bermudagrass grown in Treeo Center effluent water had the highest density. After six weeks of treatment, grasses grown in Treeo Center effluent had the highest densities.

...Leachate conductivity could be separated based on water source. Leachates collected after the 4th and 6th week of treatment indicated that Treeo Center effluent water had the highest EC, followed by UF effluent water, followed by tap water. Values in the first 2 weeks fell in the medium salinity class for all water sources. Values for UF and Treeo Center water were at the medium to high class at 4 and 6 weeks after treatment.

...Shoot dry weights increased each week when watered with Treeo Center effluent water. All treatments except tap water applied to St. Augustinegrass resulted in increased shoot weights after 4 weeks of treatment. Bermudagrass shoot production after 2 and 4 weeks of treatment remained the same when watered with UF effluent or tap water. Root length density values were influenced by water source. St. Augustinegrass roots experienced very poor growth when watered with tap water. Nutrient levels were evidently too low to sustain adequate root growth without supplemental fertilization. St. Augustinegrass produced more deeper roots when watered with Treeo Center effluent compared to UF effluent. Bermudagrass root growth across the rooting profile was similar for tap and UF effluent water treatments. Treeo Center water resulted in superior bermudagrass root growth after two and four weeks of treatments.

...In summary, evaluations indicate that a tertiary water source of effluent water can influence St. Augustinegrass and bermudagrass root and shoot growth and quality. Turfgrass quality variation in this study seemed to be influenced by water source but could not be verified statistically. Shoot dry weight and density was improved due to application of Treeo Center effluent water applications compared to tap. Data taken most weeks indicated that UF effluent water resulted in higher density turf canopies compared to tap water. The EC levels measured in Treeo Center water leachate indicate that water management may be important if this is the sole water source for long-term turfgrass growth. Very little change was noted in shoot dry weight and root length density when grasses were treated with tap water. These results indicate that nutrient content in effluent water can improve St. Augustinegrass and bermudagrass characteristics compared to tap water with minimum use of fertilizers. Further evaluation of these water sources have continued this fall.

Acknowledgement

Appreciation is extended to the Florida Turfgrass Association for funding this research. Also like to thank University of Florida Golf Course, and Kanapaha Botanical Garden for providing us with effluent water necessary for this work.

  1. Environmental Planning - each club generates a written plan outlining their goals and proposed projects.
  2. Wildlife & Habitat Management - emphasizes the management of non-play areas to provide habitat for wildlife.
  3. Integrated Pest Management - developing a responsible program for controlling pests, ensuring a healthy environment for both people and wildlife.
  4. Water Conservation - attention is directed toward irrigation systems, recapturing and reuse of water resources, maintenance practices, and turfgrass selection.
  5. Water Quality Management - directs emphasis on impact of golf course chemical use on quality of lakes, streams, and groundwater sources.
  6. Outreach & Education - focus is placed upon generating public awareness through education.

...These six areas require extensive documentation and in many cases, implementation of projects to support or strengthen the golf course’s efforts in environmental awareness and/or protection. As you can probably gather from this list, the Audubon program is taking a more holistic approach to evaluating the golf course environment, addressing the turf, water issues, wildlife, pest control, and community education.

...The University’s goal with developing BMPs for golf courses is primarily focused on growing quality turf in the most ecologically friendly way, but we do not specifically address the extensive monitoring or the community outreach and education components as outlined in the Audubon program. It is my experience that most of the University directed golf course turf programs are geared toward the people that manage the turf rather than the end user (e.g. the golfer). The Audubon outreach and education programs are designed primarily for the golfers and potential future golfers. Which program is the best? They both serve an important function for the sustainable future of this industry.