By: Jonah Reyes, Research Scientist
The University of Minnesota has been working with the Minnesota Department of Transportation on improving the success of salt-tolerant turfgrass mixtures established as seed and sod. Salt tolerant mixtures are composed primarily of fine fescues and the current specified mixture is MNST-12. A major factor that has been attributed to limited success of this mixture is the insufficient application of water during the establishment period. To study this, three irrigation methods were evaluated in 2016; 12” and 18” emitter spacing drip irrigation systems and a fixed spray system using Hunter MP Rotator nozzles. We designed a six-treatment trial using these three irrigation methods and replicated each treatment three times. The systems were installed on plots seeded or sodded with the MNST-12 mixture at two boulevard sites with a water hydrant and one sloped site located at the Turfgrass Research Center in St. Paul. The following is a list of these treatments:
- 12” x 12” drip tape style irrigation placed BELOW sod or to a ½” depth in soil for seed
- 12” x 12” drip tape style irrigation placed ABOVE sod or at the soil surface for seed
- 18” x 18” drip tape style irrigation placed BELOW sod or to a ½” depth in soil for seed
- 18” x 18” drip tape style irrigation placed ABOVE sod or at the soil surface for seed
- Overhead irrigation with MP Rotator
- Un-irrigated control
After the 60-day establishment period, the above sod drip irrigation treatments maintained acceptable quality of MNST-12 sod. The highest ratings for green tissue and quality were achieved with the 12”x12” drip irrigation design placed above sod (Image 1), followed by 18”x18” above sod systems (Image 2). Below sod drip systems provided intermediate quality, while the overhead irrigation design received the lowest quality ratings of the irrigated treatments. The poor performance of the below sod treatments was attributed to a lack of turf quality and rooting of sod above the drip line. The poor performance of the fixed spray irrigation systems was attributed to the reduction in water distribution near the outside edges of the plots. The unirrigated control treatments did not produce acceptable establishment and the sod appeared to be dead approximately 5-6 days after planting (Image 3).
Throughout the trial period, irrigation volumes were programmed based on observed soil moisture requirements. Prior to planting sod, the soil was pre-wet to minimize the initial shock from sod placed on dry soil. On the day of planting, 0.15” of irrigation was applied in two separate cycles. For the 10-day period following planting, both seed and sod treatments were irrigated with 0.15” of water 2x per day for a daily total of 0.30” and a weekly total of 2.1”.
Days 11-30, seed and sod were irrigated with 0.15” per day (1.05” weekly), and days 31-60 irrigation was applied every other day at 0.15” (0.45” to 0.60” weekly). Over the 60-day trial period, 14,212 gallons or an equivalent of 11″ of water was applied to the trial area, costing $62.80.
Volumetric Water Content (VWC) using a TDR 300 Soil Moisture Meter including GPS and visual ratings were recorded weekly. After the 60 day establishment period, turfgrass species and weed counts were recorded. Future ratings and evaluation of the 2016 sites will be recorded as well as the installation on two more sites next year.
|May 27||June 2||June 10||June 17||June 24||July 1||July 7||July 14|
|Treatment||% Green||% Green||Quality||Quality||Quality||Quality||Quality||Quality|
|12 x 12 A||91.7||95.0||7.7||7.3||7.3||7||7||7|
|12 x 12 B||63.3||65.0||5||5.3||5||5||5||5|
|18 x 18 A||83.3||86.7||7||7||6.7||6||6||6|
|18 x 18 B||80.0||81.7||6||6.3||6.3||5.7||5.7||6|
Figure 1. Percent green tissue and turfgrass quality ratings for MNST-12 sod planted on May 19th, 2016 on Larpentuer Ave. in St. Paul. Quality ratings are on a 1-9 scale where 1= worst and 9 = best. A rating of 6 is considered acceptable.
Any investment in quality continuing education opportunities benefits employees and employers alike. The 2017 Great Lakes School of Turfgrass Science Online is designed to help meet the continuing education needs of any individual or organization. This 12-week program will have training sessions accessible live online on Wednesday evenings from 6 to 8pm (Central Standard Time) or the option to view the recorded sessions. This 12-week certificate-based program aims to provide participants with thorough and practical continuing education in turfgrass management. The course is directed by educators from the University of Minnesota-Twin Cites and the University of Wisconsin-Madison, with 12 turfgrass scientists and educators from seven Land-Grant Universities.
Turfgrasses are a resource in our urban community environments and best management practices are aligned with environmental, economic & societal priorities. The Great Lakes School of Turfgrass Science provides participants with the science based principles needed to effectively manage turf for recreation, sport, aesthetics and environmental protection. The Great Lakes School of Turfgrass Science is a quality training opportunity for:
- Practitioners that establish and maintain turfgrass for athletic fields, consumer/commercial lawns, golf courses, recreation/parks, and sod production
- Technical representatives from industry (suppliers of equipment, plant protectants, fertilizer, etc.)
- Those new to the industry – wanting to get trained and off to a great start
- Those with experience in the industry – to review/update their knowledge and practices
The registration deadline is December 23rd, 2016. Students will have access to the course and materials at their convenience during the 12-week period via moodle class management system. The fee for the course is $495, which includes supplemental materials and a certificate after successful completion of the program. Visit this link to register: http://z.umn.edu/2017glst
For Further Information: Contact Sam Bauer, Assistant Extension Professor – University of Minnesota, Email: firstname.lastname@example.org Phone: 763-767-3518.
Join us for the 2016 University of Minnesota and Minnesota Turf and Grounds Foundation Field Day, August 11th
By Parker Anderson, Research Scientist
Science of the Green Initiative
The Turfgrass Science Research Lab’s Science of the Green Initiative, a research partnership between the University of Minnesota and the United States Golf Association, just completed its pilot of a nation-wide study on the impact of course conditions on pace of play. This portion of the study focuses on the variable of green speed. Green speeds not only impact player experience but also the maintenance practices of course superintendents. The pilot study was conducted at the Philadelphia Cricket Club Militia Hill Course just outside of Philadelphia, PA. A University of Minnesota Turfgrass Researcher worked with the host superintendent to adjust the speed of the greens (Image 1) in three consecutive weeks while maintaining the rest of the course consistent with the standards of their facility. Golfers participating in the study were given GPS loggers (Image 2) to carry in their pocket. The GPS loggers captured time and location of each golfer during their round. The GPS loggers were then collected at the end of the round and the data analyzed. The result for each golfer is a “track” of their path throughout their round (Image 3). Researchers can now analyze these tracks and compare the tracks from week to week focusing on the player’s interaction with the green. Future study sites for this project will be in Minnesota, Northern California, the Carolinas, and Philadelphia.
The 2015 Cultivar Evaluation Results are now available and published online. To view these results, click the “Cultivar Evaluation Results” tab under the Research section on the left of this webpage. Clicking this link will initially bring you to the 2015 data page, but you can view archived data from 2007-2013 as well. Study labels are preceded by the date in which that study was planted. For example, “2011 NTEP Kentucky bluegrass” was established in 2011, but you will be viewing the most recent data if you are in the 2015 tab.
How to use the results:
Some trials may have 100 or more entries. Generally, named cultivars (ex: ‘Beacon’ hard fescue) will be commercially available through big box stores, garden centers, seed distributors, or professional suppliers. Numbered entries are experimental and not available for purchase (ex: ASR172 slender creeping red fescue). The main rating of concern when looking to purchase a particular cultivar will be turfgrass quality, which is a 1 to 9 scale rating where 1 = worst turf quality or dead turf, 6 = minimum quality acceptable, and 9 = best possible quality. The LSD (least significant difference) at the bottom of each table is a statistical value that can be useful for determining if one cultivar is different from another. A LSD value of 0.7 would mean that statistically a rating of 6.6 is not different than 6.0, but a rating of 5.9 would be.