Strategies for Removing Ice from Annual Bluegrass (poa annua) Golf Course Greens (2003)
D.K. Tompkins, J.B. Ross and M.K. Anderson, Prairie Turfgrass Research Centre, Olds College, Olds, Alberta
Ice cover on annual bluegrass (Poa annua L.) putting greens often causes damage in the cold climates of North America during long winters. For golf course superintendents, ice removal from annual bluegrass greens is an important part of preventing winter injury. However, there is a lot of confusion about the best method and timing of the ice removal. The objective of this study is to evaluate various ice removal strategies for use on annual bluegrass putting greens. In addition, the various products were evaluated for their phytotoxicity (damage caused by the product) to the turf. An initial screening study was conducted in order to choose the best treatments for the field study. Selection of treatments was based on effectiveness in melting the ice and phytotoxicity of the products. Results of the field study that was conducted in March 2004, are preliminary in nature. The clear polyethylene and the no cover treatments appeared to be superior to the black polyethylene cover. As far as the individual treatments were concerned, the two ice melters, Landscape® and Alaskan®, appeared to soften the ice more rapidly than the other treatments.
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Nutrient and Rhizosphere Management of Amended Sand Greens (1999 - Final Report)
F.B. Holl, The University of British Columbia
This trial was established to assess the effect of different amendments, nitrogen fertility sources and carbon supplementation on turfgrass quality and measures of soil microbial community activity. While amendment differences were not extreme, it was evident that any amendment that improved the water and/or nutrient-holding capacity on a sand-based profile could contribute to improved turf quality. On the data from this trial, no strong argument can be made to replace peat as the common amendment in sand-based greens.
There was some evidence to support the contention that organic nitrogen sources could enhance turfgrass performance. In particular, there was some evidence for enhanced microbial activity and more enduring retention of turf quality into the fall. While these data are supportive of the use of organic nitrogen sources, it should also be noted that during the establishment phase, there were some clear indications that the response to inorganic nitrogen was more dependable than the organic treatment. It is likely that a combination of inorganic and organic nitrogen fertility will contribute to the development of a high quality well-established turf with an effective, healthy microbial population. The inclusion of organic nitrogen in topdressing mixes, a practice that is increasingly common, may be an effective means of incorporating that organic component into the amended sand profile. The inclusion of this organic component can be used to derive the benefits of both the nutrient content of the fertilizer, as well as the contribution of the other organic components to the development of a beneficial population of soil microbes.
The impact of carbon supplementation was evident in both turf quality and microbial community development. It has been argued that sand-based profiles are deficient in carbon to support the normal microbial populations found in a healthy soil. This situation is particularly evident in newly established turf on a sand, or amended sand base. Although the Carbo-Aid product is not commercially available in Canada, there are alternatives that could provide a similar response. These include the use of agricultural grade molasses and any of several humic acid products; superintendents have used both of these sources with some success in enhancing turfgrass performance. Even though specific evaluation of microbial populations has not been part of that evaluation process, it is highly likely that at least part of the positive response to supplementation in these cases is attributable to the impact of the supplemental carbon on microbial populations.
The techniques we have used for assessing microbial populations require relatively sophisticated laboratory facilities and are not easily transferable to direct application by turf managers. We believe that it should be possible to modify the BIOLOG‘ system so that it could be used as a practical assessment technique to determine the functionality of soil microbial populations. Work to adapt this analytical research technique into a practical tool that could be used by turf managers is continuing. (summary by Leslie Macdonald)
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Evaluation of Turfgrass Quality, Thatch Development and Rooting Environment of Poa reptans Under Different Thatch Management Regimes (2002)
Dr. Brian Holl with Bentley Sly & Steve Haggard, Northlands Golf Club
The results of this trial suggest that:
- Conventional core aeration (2x per year) is an effective cultural tool for management of thatch and turf quality of Poa reptans greens
- Supplementation of core aeration with humates and molasses can contribute to reducing thatch levels in Poa reptans greens
- Soil temperature variation in the root zone is likely to be a significant environmental influence on root development and the soil microbial community. Additional trials to monitor soil moisture and temperature in conjunction with root growth and turf quality would be useful to assist our understanding of the impact of these factors on plant health and performance of these Poa reptans greens.
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Increasing O2 Levels and Decreasing Anaerobic Conditions in the Rootzone on Sand Based Turf (2000)
Peter Szarka, Golf Course Superintendent, The Redwood Golf Course, Fort Langley, BC
There seemed to be very little visible change in turf quality (roots or turf density). There was also little visible change in the turf's recuperative ability to repair ball mark damage any quicker than normal. This lack of visible improvement in turf quality is probably due to the fact that these treatments were performed during a period of exceptional growing conditions. Any benefits that may have been visible could have been masked by this good period of growth (especially for roots).
Our O2 results may have only increased 4% - 22%, but this doesn't give us any indication that perhaps the plant isn't happy already with oxygen levels between 14% and 18 %.
The CO2 readings were encouraging as we know that high CO2 levels are toxic to roots. These treatments that lowered CO2 levels on and off quite likely raised plant health and vigor and was probably better equipped to handle stress and disease. Long term studies on whether this is true may indicate less fungicide use per annum.
As expected, we forcibly leached out "leachable" nutrients from the rootzone; but overall, the physical amount of each turned out to be negligible versus the amount in the soil solutions needed by the plant. This treatment would probably have little or no detrimental affect on a fertility program. As treatments continue, bi-annual soil tests should confirm this conclusion.
Overall, raising O2 levels, decreasing CO2 levels and removing excess water (albeit for short intervals) makes good agronomic sense. Although these results on paper are hard to translate into visible differences on the turf, the use of a Sub-Air type of vacuum system does make good sense as one of many tools used in the effort to grow and maintain healthy, vigorous turf grass.
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Improvement of Wear Problems on Sand-based Fields and Quantitative Assessment of Field Quality (1999)
By Elisabeth Deom Eldridge and Deborah Henderson, Vancouver, BC
The increasing use of sports fields, and particularly their high demand during the rainy winter months leads to turf wear, surface compaction and reduced playing quality. This project had three objectives:
Compare the efficiency of 3 soil amendments in alleviating soil compaction and improving turfgrass wear tolerance on athletic sand fields.
- Evaluate the effect of crumb rubber topdressings on turf wear and soil condition.
- Assess playing quality across a playing field on the basis of surface characteristics and player evaluation.
Goal mouth and centre field areas of a sand-based field at the Burnaby Lake Sports Complex were used to examine the first objective. Plots were established in July 1997 and measurements were taken during the following 2 years.
High turf quality and density were maintained with the crumb rubber treatments during the first season but not the second season. Crumb rubber treated areas also had a high percent of ground coverage during the first season which was comparable to the cover on areas receiving low traffic. This effect was not observed during the second season. In general it can be concluded that there is limited benefit by the second year after crumb rubber is applied at a depth of 6 mm. This concurs with Dr. Trey Rogers' research where he has found that a minimum of 0.5 to 0.75 inch depth is required for the best benefit. See his article on the web at www.css.msu/Crumb_Rubber.cfm for further information.
- There was no significant difference in turf quality between the pumice treatment(450 lbs/1000 ft2), the Axis treatment (165 lbs/1000 ft2), and the untreated control.
- Crumb rubber at a thickness of 6 mm (800 lbs/1000 ft2) significantly lowered surface hardness the first season after application.
- Thatch levels were lower with the crumb rubber treatment on two sampling dates, but on four other sampling dates there was no difference between any of the treatments.
In the second trial, crumb rubber was applied August 31, 1998 and May 26, 1999 to a total depth of either 6 mm (800 lbs/1000 ft2) or 12 mm (1600 lbs/1000 ft2) depending on the treatment. Untreated areas were left as controls.
- Statistical analysis of the data did not indicate significant differences in turf quality, turf density, cover, root depth and soil moisture content between the three treatments.
- However trends showed that crumb rubber improved turf quality during the spring, and turf density in the winter and spring following the first application. Trends also showed that the crumb rubber improved the percent ground cover during the winter and spring following the first application.
- Early green-up and improved turf density were noticed on the strips treated with crumb rubber, possibly due to the effect of rubber on surface temperature.
- Crumb rubber significantly reduced surface hardness during the first season. Thatch thickness was also significantly reduced in the first season. Reduced surface hardness and reduced thatch continued into the second season but the differences were not significant.
- The lack of clear-cut differences in turf quality between the treatments may be partially explained by the fact that heavy use prior to the second application caused major wear damage to the goal mouth and centre areas of the field. As a result, there was a limited benefit from the next addition of crumb rubber. Dr. Rogers has also found that crumb rubber is most effective as a preventive treatment applied to healthy turf. It is not a cure-all to bring turf back to good health.
Player evaluations found no differences in response between the quality of the centre area (treated with crumb rubber) and the entire field. The width of the strips and pattern of play and assessment did not allow for an adequate evaluation of the performance of the treatments. Additional measurements such as ball response characteristics and surface evenness need to be recorded as well and compared to players' evaluation of field quality over several different fields to obtain a complete quantitative assessment of the quality and safety of playing surfaces in our region. (summary by Leslie Macdonald)
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The Benefits of Turf Quality with the use of Ecolite as a Soil Amendment / Top Dress Material (1998)
By Danny Rolfe, Belmont Golf Club, Fort Langley, BC
In conclusion to the research completed on the benefits of turf quality with the use of Ecolite as a soil amendment / top dress material there has been insufficient evidence obtained that Ecolite provided an increase in turf quality. Although very similar in texture and ease of use compared to sand as a soil amendment / top dress material, the results showed Ecolite did not prove to have any greater benefits. The findings from this report provide a practical demonstration of one of the many types of products available to the turf manager, to help develop yet a better environment in which to grow turfgrass. Although this study did not provide the test plots at Belmont G.C. with better turf quality, it also did not provide us with any poorer quality either. In any case, this practical research demonstration project provides us with a better understanding of a product in which many questions may have been unanswered. I hope someone, somewhere can benefit from this information.
This fall, a comprehensive survey of superintendents, of golfers and club members will be conducted to quantify the number of casts per square meter that is acceptable. Earthworm casting is an issue that inevitably will require some tolerance on the part of golfers. It is very unfortunate and unfair that there are superintendents around the country that face so much pressure over the casting that they fear losing their jobs. After all, earthworms prefer the same conditions required to maintain healthy turfgrass. In addition, we must remember that earthworms provide far more benefits to the soil/turf environment than they do harm. The earthworm's burrowing and feeding activity initiates thatch decomposition, stimulates microbial activity, makes certain plant nutrients more available, increases soil aeration, and in general improves overall soil quality.
Our research project will continue until we are able to develop an Integrated Management System for reducing casting. We will also continue to look at new strategies that have not been previously tested for earthworm casting reduction.
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Iron Sulphate: A Blessing in Disguise (1997)
By Kristian Sorensen, Capilano Golf and Country Club, West Vancouver, BC
Suppression of weeds and fungal diseases on turf can be costly and difficult to achieve, especially in areas where the use of chemicals is restricted or prohibited. The use of additional products, such as plant nutrients, offer safe alternatives.
This study showed that applications of iron sulphate can successfully reduce the growth of creeping speedwell, when applied at a rate as low as 8 oz./1000 sq. ft. However, several applications are necessary to successfully suppress the weeds.
In addition to suppressing weeds, applications of iron reduced the incidence of Fusarium as well as Red thread diseases. The effect was shown to be of a curative nature rather than preventive, indicating that applications should begin after the development of disease symptoms.
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A Comparison of Turf Performance, Soil Microbial Activity and the Effects of Organic Top Dressings in Sand and Sand/Peat Based Sport Fields (1997)
Ken Ng and Stephen Wong, Environment and Operations, Vancouver Parks
Turfgrass performance, as well as disease suppression are important in the maintenance of safe and healthy sports fields. The first part of this study was designed to compare turf performance and soil microbial levels of a peat-amended field and a sand field. Results showed improved turf density and root mass on the field amended with peat, compared to the sand-based field. Furthermore, higher overall levels of beneficial microbes were recorded on the peat-amended field at the end of the summer.
Microbes, particularly the disease suppressing types, help improve overall field performance and turf quality; maintaining adequate levels in a field is important. Peat and other organic matter sources, with their increased nutrient and water-holding capacities, help maintain a healthy turf as well as provide a favorable environment for microorganisms. Small quantities of organic matter, incorporated into the sand profile seem to provide the needed requirements to maintain a healthy turf stand.
The second part of the study investigated the effects of 5 top dressing material on turf performance, on both the sand and peat-amended fields. Chitin was the most efficient top dressing material, as measured by greater top growth, visual quality rating and lower levels of Red thread disease. Similarly, compost promoted turf growth and health, but the effects were of a shorter duration. In addition, the positive effects of top dressing were more evident in the peat-amended field than in the sand field.
A second application of topdressing material was done in the fall of 1997 to examine the long term effects of organic amendments on turfgrass health and on microbial activity in both fields. Chitin and compost as by-products of industries may provide the turf industry with valuable economical products to promote and maintain healthy turf.
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Improvement of Wear and Compaction (traffic) Problems on Sand-based Fields (1997)
By Elisabeth Deom Eldridge , Deborah Henderson, Ph.D. (E.S. Cropconsult Ltd.), Vancouver, BC
The present study showed various effects of soil amendments on turfgrass and soil characteristics. Soil aeration porosity remained higher in heavy traffic areas treated with pumice and crumb rubber. Improved turf cover, quality and density, as well as early spring green up were observed when crumb rubber was applied as a topdressing material. Reduced surface hardness was also observed in areas treated with crumb rubber.
A single application of crumb rubber, during the season, provided significant benefits to both turf and soil characteristics. Additional investigation is required in order to determine whether the observed benefits are extending into the second year. Whether it is possible to increase the observed benefits further by applying more than once in the season should also be investigated.
Preliminary results of field quality showed interesting but inconclusive results on the range of soil moisture, turf characteristics and surface characteristics across a playing field. Additional measurements such as ball response characteristics and surface evenness should be recorded and compared to players' evaluation of field quality in order to provide a complete quantitative assessment of the quality and safety of the playing surface.
A second trial, using crumb rubber, has been set up for 1998 to address some of the above mentioned concerns. The treated areas have been enlarged to better reflect actual management practices.
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