Golf Green Research Articles

Soil Gas, Temperature, Matric Potential, and Creeping Bentgrass Growth Response to Subsurface Air Movement on a Sand-based Golf Green

Creeping bentgrass (Agrostis palustris Huds.) is used on putting greens for its fine-leaf texture, consistent speed, smooth ball roll, and year-round color. In recent years bentgrass use has extended into the warmer climates of the southern United States. Being a C3 plant, bentgrass is not well adapted to extended hot and humid environmental conditions. Subsurface air movement systems are now commercially available that can transport air through the root zone to alter soil conditions and potentially improve bentgrass survival. This research investigated the effects of subsurface air movement on the composition of soil gases, matric potential, temperature, and growth response of a sand-based creeping bentgrass golf green. Treatments included: air movement direction (evacuate, inject, and no air) and duration of air movement (0400-0600 hr, 1000-1800 hr, and 24 hours). Treatment combinations were imposed for 13 days. Subsurface air movement reduced CO2 at the 9-cm depth to values <0.0033 mol·mol-1 when evacuating or injecting air, depending upon duration. Soil matric potentials at a 9-cm depth were decreased by a maximum of 96% when evacuating air for 24-hour duration compared to no-air plots. Soil temperatures at 9 cm were decreased ≈1 to 1.5 °C when injecting air from 1000 to 1800 hr and 24-hour treatments and increased ≈0.75 °C when evacuating air from 1000 to 1800 hr. Subsurface air movement did not improve creeping bentgrass turf quality or rooting. Although not effective in improving the growth response of creeping bentgrass, subsurface air movement may be a useful tool to improve soil gas composition, reduce excess soil moisture, and potentially reduce soil temperature(s) of heat-stressed creeping bentgrass golf greens.

Camping to change the world

Keynote given at the 6th International Camping Congress, La Trobe University, Bundoora, 6 January 2003. Reprinted with permission from the Camping Association of Victoria. Also available on: http://www.icc2003.cav.asn.au/ Abstract As well as providing amazing recreational experiences, camping can nurture our connection with both nature and one another. The development of such deeper relational competence is needed for our species to take the next step in our psychosocial evolution. Without this we can expect ongoing environmental degradation, social strife and personal anxiety. By being aware of the philosophical underpinnings and possible practical applications of these ideas, we can all be in a better position to appreciate and experience camping at a much deeper and rewarding level. This holistic view of camping aims to integrate humour, humility and hope. As a youngster I remember laughing at the definition of camping as "loitering with-in-tent". In this presentation I want to reframe and examine deeply what that 'intent' might be, how it gets constructed, and what the consequences of different 'intents' might be. As indicated in my title, I believe that camping - along with many other activities - has the potential to change the world (for the better). Camping can be both a means for developing our 'good intent', and for taking meaningful action to create the better world(s) we would want to live in, and that we would want to pass on to future generations. Perhaps I should first tell you where I am coming from, a little about my association with camping, and about some of my assumptions and the frameworks I use to think about topics such as the one we are dealing with. I was born in Aylesbury in the UK during WWII, and we camped throughout my youth - both with my family and through the Cubs and Scouts. I did some camping with my children in North America, and I camp occasionally now with my partner in Australia, where I have lived since 1995. In addition, each year a group of us take our Social Ecology undergraduate students for a one-week camping trip in the Blue Mountains (at Glastonbell, near Bell, NSW). I looked up 'camping' in the 'Oxford Book of Quotations' and the only reference was to H.G. Wells, who in his novel Bealby (Part III, p. 7) stated: The life of breezy freedom resolves itself in practice chiefly into washing up and an anxious search for permission to camp. This certainly was an important part of my memory of camping with my family. It is interesting that in Lancashire, where my father comes from, the word 'camping' is used to refer to situations when someone engages you in conversation, for example, when you meet someone unexpectedly on the street. I also remember having numerous meaningful conversations with other campers. One meaning of the Latin word campus, from which 'camping' is derived, is 'level ground'. I certainly remember much time spent searching for such ground - and also sometimes crawling into my sleeping bag only to find that the bit of ground I was on was far from level. One of my father's entertaining stories relates to a camping trip that he made as a young Sea Scout. On the last day of the trek he arrived about midnight on Chorleywood Common (Hertfordshire). It was pitch black with no moonlight, and he had no torch, so it was difficult to find a suitable site, until by chance he came upon a piece of flat ground. He pitched his tent quickly and, being exhausted from the long trek, went to sleep immediately. He was awakened in the morning by a very angry local - an early morning golfer. He had pitched his tent on the golf green of the 9th hole! An innocent mistake, but one he would never make again. With my love of nature, I did an undergraduate degree in zoology and a PhD in ecology - which involved spending two years studying life in a bat-inhabited cave in Trinidad. There my camp was a hammock covered in a mosquito net strung between two trees close to the cave mouth. …

Use of Transparent Columns for Demonstrating Water Movement in Golf Green Root Zones

Use of Transparent Columns for Demonstrating Water Movement in Golf Green Root Zones

Golf Green Soil and Crown‐Level Temperatures under Winter Protective Covers

AbstractWinter protective covers are currently used in northern climates to mitigate winter damages on golf greens. Despite the critical importance of soil temperature on winter survival of golf greens, little information exists on the effects of commercially available protective covers on soil temperatures regimes during winter. This 3‐yr (1993–1996) field study was conducted to determine the influence of different winter protective covers on golf green soil temperature under two northern climate conditions (thick or thin snow cover). Six winter protection treatments were tested: permeable covers; impermeable covers; curled wood shavings mat, straw mulch, and 5 cm air space (each under an impermeable cover); and a control treatment without any protection. Daily climatological data and soil temperatures under protective covers were recorded at two experimental sites (Quebec City and St‐Lambert, Montreal, Canada). Throughout the winter seasons, soil temperatures under protective covers and control plots remained around 0°C under a thick and stable snow cover (average of 42 cm during experiment). Under .thin snow cover (average of 6 cm during experiment), minimum crown temperatures were markedly influenced by winter covers and reached a minimum over all years of −20.6, −19.5, −18.2, −11.1, −6.6,and −1.0°C for control, impermeable, permeable, curled wood mat, air space, and straw treatments, respectively. The insulating material covers (curled wood mat, air space, and straw) reduced soil temperature variation ranges, minimized the impact of freezing air temperature and thin snow cover, and consequently enhanced winter survival of golf greens under thin snow cover. Thus, depending on local conditions, and particularly on snow cover, the characteristics of specific protective covers can influence golf green soil temperatures and turfgrass survival during the overwintering period.

Growth Response of Agrostis palustris to Adventitious Root Infection by Acremonium rutilum and Acremonium alternatum

Abstract Acremonium rutilum and Acremonium alternatum are reported as pathogens of the adventitious roots of Agrostis palustris. Both organisms have been isolated from root and leaf tissue of diseased A. palustris on high‐sand‐content golf greens. The presence of the organisms on adventitious roots is usually associated with other potential root pathogens. Three isolates of A. rutilum and one isolate of A. alternatum were evaluated for their ability to infect adventitious roots of A. palustris under high and low temperature regimes and to affect plant growth and symptom expression. Both species of Acremonium infected roots and decreased shoot and root dry weight. The decreases in dry weight were more pronounced under low temperatures than under high temperatures. With the exception of isolate AR‐1 of A. rutilum under the high temperature regime, the decrease in shoot dry weight was disproportionately greater than that of root weight in response to both A. rutilum and A. alternatum. The number of stolons per plant decreased in response to both species of Acremonium under the high and low temperature regimes except for isolate AR‐1 of A. rutilum which increased stolon numbers under the high temperature regime. Foliar symptoms associated with the organisms in the field were not expressed by the root‐inoculated plants. The observations of the study are discussed relative to A. rutilum and A. alternatum as potential emerging pathogens and/or participants in a root disease complex, and relative to the role of high‐sand‐content golf green management practices in the process.

The Effect of Rootzone Composition on the Playing Quality of Festuca/Agrostis/Poa annua Golf Greens

Playing characteristics were measured for sixteen golf green rootzone mixes, formed from combinations of four sand types and four mixing ratios of sand to sandy loam soil. At the start of the monitoring period, the turf was 2.5 years old and simulated golf-type wear was applied during the eighteen months of the study. Green speed, measured as distance rolled, was generally not influenced by rootzone type. However, the hardness of the surface was influenced by the amount and type of sand in the mix and soil moisture content. In wet conditions rootzones with a high sand content gave a firmer playing surface, but in dry conditions this situation was generally reversed. Rootzones constructed with finer sands tended to give a softer surface, especially in wet weather. Rootzones constructed from sands with a wider range of particles generally gave a harder surface than when uniform sands were used. Stopping distance of the ball fired into the turf at an angle of 53° with backspin of 717 rad/s was also influenced by sand content, sand type, moisture content and pitchmark depth. Sand-dominated surfaces gave more consistent playing quality.

The Design and Construction of the Floating Golf Green

This paper relates the evolution of a design and construction project of interest to the engineering community, that of a floating golf green. It also presents technical details on the unique aspects of this project and elucidates the design development process by explaining the evolution of technical criteria and their application to the facility design. A patented technique for construction of a large rigid pontoon from small prefabricated modules is described and final design and construction details are summarized. Numerous naval architecture and engineering tasks covering various disciplines were involved, including: design of steel, concrete, and composite structures; climatology assessment; determination of structural wave loads and mooring loads; design of fixed and adjustable mooring systems; provision of aesthetic design: design of piping systems; and development of weight assessment tools.

High pH Treatments and the Alleviation of Soil Hydrophobicity on Golf Greens

AbstractHydrophobic soil associated with localized dry spots (LDS) on creeping bentgrass (Agrostis palustris Huds.) putting greens has been shown to be caused by a humic and/or fulvic acid coating of the sand particles. Under laboratory conditions, humic acid begins to solubilize at pH 7.0 and is completely soluble at pH 9.5 or greater. The purpose of this study was to determine the potential of high pH treatments for alleviating soil hydrophobicity of a creeping bentgrass golf green. Three separate studies were conducted on the University of Georgia Experimental Golf Green, Athens, GA, during the spring and summer of 1990 and spring of 1991. The creeping bentgrass green, constructed with an 85% sand and 15% peat root zone mixture, had a well documented history of LDS caused by hydrophobic soil. Soil hydrophobicity was determined by the molarity of an aqueous ethanol droplet (MED) technique. Results showed that an application of 0.1 M NaOH sufficient to saturate the upper 50 mm of soil, followed by a water flush of one pore volume, significantly reduced soil hydrophobicity if repeated three or more times. In one study, soil hydrophobicity was completely eliminated after nine consecutive daily treatments of 0.1 M NaOH, each of which was followed by a water flush. A concurrent decrease in soil humic matter content suggested that its dissolution and removal was responsible for the increased wettability of the soil profile. Bentgrass treated with NaOH showed varying degrees of phytotoxicity. The severity of injury depended on the number of consecutive applications and air temperature. Little or no discoloration was noted when air temperatures was ≤24 °C; however, severe wilt and desiccation occurred when treatments were applied when air temperature was ≥ °C. High pH treatments may be an effective means to reduce soil hydrophobicity on sand‐based golf putting greens.

Control of Cutworms in a Golf Green with Entomopathogenic Nematodes, 1992:

Abstract This study was conducted on a creeping bentgrass golf green at the Campbell House Golf Club, Lexington, KY. The green had been topdressed with sand over native soil. Plots (10 X 10 ft) were established in a RCB design with 5 replicates. The target population consisted of mixed instars of both black and bronzed cutworms. Treatments were applied as surface sprays (5 gal/1000 ft2) using pump-type, backpack sprayers equipped with a fan-type nozzle. Plots were treated on 13 Aug. Dursban plots were treated at 11 AM with the spray allowed to dry on the turf surface. Nematode plots were treated 2 h later, followed immediately by irrigation with 0.25 inch of water to all plots. Temperature at the time of the nematode treatment was 74°F, with 76% relative humidity and 4 mph winds. Cutworms were sampled 7 DAT. A frame (6.6 x 6.6 ft) made from PVC pipe was first placed in the center of each plot. Four gallons of an irritant drench (1 oz of Joy liquid detergent/ gal water) were applied to the area defined by the frame using a sprinkling can, and the number of cutworms that surfaced within 10 min was recorded.

Iron Fertilization Effects on Shoot/Root Growth, Water Use, and Drought Stress of Creeping Bentgrass

AbstractCreeping bentgrass (Agrostis palustris Huds.) golf greens in the U.S. Southeast are subjected to summer drought and heat stresses. This study was initiated to determine the effects of foliar Fe on FC‐sufficient bentgrass shoot responses, root growth, and respones to drought stress. Ferrous sulfate (FS), Lawn‐Plex (LP), and Sequestrene 330 (Seq. 330) (FeSO4‐7H2O; Fe phosphate‐citrate; and sodium ferric diethlenetriamine‐pentaacetate, respectively) were applied to a golf green at 1.12 kg Fe ha−1 per month for a 17‐mo period. All Fe sources improved color and visual quality throughout the year; summer color improved 5.9% compared to 8.6 to 9.5% for all other seasons. Total extractable tissue Fe was not well correlated with color (r < 0.54). Iron carriers had different effects on growth, especially between late summer and winter. Lawn‐Plex increased cool‐season clipping yields while Seq. 330 reduced verdure in the summer by 18% compared to the control. Root growth (weight and length) was equal to, or less than the control for all Fe treatments. In August, FS‐treated plants exhibited a 31% decrease in root length density (RLD) in the 0 to 10 cm zone. In October, 10‐ to 20‐cm depth RLDs were reduced relative to the control by 31% for FS and 28% LP for treatments. While LP tended to reduce rooting, it was the only Fe carrier to exhibit consistently better (15– 40%) soil moisture extraction than the control. Iron had no apparent effect on canopy temperature as a stress indicator. Since shoot growth, root growth, and water extraction responses often varied with Fe carrier, many reported Fe effects are probably due to the carrier rather than Fe. Exceptions would be the color and visual quality improvements observed for all Fe carriers.

Measuring Water Infiltration Rates of Sports Turf Areas

AbstractMeasuring the rate of decline of ponded water in rings is commonly used to determine water infiltration rates on turfgrass sites. Recently rings smaller than 30 cm in diameter have been marketed and used. This research examined the utility of 15‐ and 20‐cm diam. rings used as single or as double rings as well as 30‐ and 50‐cm diam. double rings for measuring water infiltration rate into golf greens and athletic fields. Results indicated that infiltration rates measured by any ring, including the 30‐ and 50‐cm diam. double ring, varied widely on a single golf green or athletic field. Infiltration rates measured with smaller rings used either as single or as double rings did not always correspond well with infiltration rates measured by the larger double rings. Infiltration rates measured with ponded water in single or double rings on sports turf areas should be viewed only as rough estimates and results should be used with caution.

Bermudagrass Encroachment into Creeping Bentgrass as Affected by Herbicides and Plant Growth Regulators

Bermudagrass (Cynodon spp.) encroachment into creeping bentgrass (Agrostis stolonifera var. palustris Huds.) golf greens is a severe problem where both grasses are grown. Research was initiated to determine the effects of dates and frequency of herbicide‐plant growth regulator (PGR) treatments on tolerance of creeping bentgrass and encroachment of three bermudagrass cultivars under golf green conditions. Treatments were arranged in a split‐plot design with frequency of herbicide‐PGR application as main plots and bermudagrass cultivars as subplots. Soil type was an artificial rootzone mix. Creeping bentgrass was injured more when treated with various herbicide‐PGR combinations in September than in April. However, creeping bentgrass injury was unacceptable (>30%) with mefluidide {N‐[2,4‐dimethyl‐5‐[[(trifluoromethyl)‐sulfonyl] amino]phenyl]acetamide} applied in sequence with siduron [N‐(2‐methyl‐cyclohexyl]‐N‐phenylurea] or ethofumesate [(±)2‐ethoxy‐2,3‐dihydro‐3,3‐dimethyl‐5‐benzofuranyl methanesulfonate] at either date. In general, herbicide‐PGR treatments applied in April suppressed foliage and stolon growth of bermudagrass equal to or better than treatments applied in September and April. Bermudagrass growth was effectively suppressed until late May or early June when treated with siduron, siduron with flurprimidol {α‐(1‐methylethyl)‐α‐[4‐(trifluoromethoxy)‐phenyl]‐5‐pyrimidine‐methanol}, or ethofumesate with flurprimidol. There generally was no difference in foliar growth suppression from treatments applied to ‘Tifway’, ‘Tifgreen’, both C. transvaalensis Burtt‐Davy ✕ C. dactylon (L.) Pers., and common bermudagrass, C. dactylon (L.) Pers. When chemicals were applied only in April, the length and number of bermudagrass stolons were effectively suppressed for several weeks but stolon growth recovered and increased rapidly from mid‐May until June. The suppression of stolon growth of all bermudagrass cultivars in June was as good or better when treated with ethofumesate plus flurprimidol than with other treatments.

Biology of Poa annua in a Temperature Zone Golf Putting Green (Agrostis stolonifera/Poa annua). I. The Above-Ground Population

(1) Seasonal changes in the above-ground population of a temperate zone golf green were studied for 2 years by destructive sampling (coring and sorting). (2) Five species were identified in the green. Only Poa annua and Agrostis stolonifera were numerically significant and they formed a mosaic of patches dominated by one species or the other. The P. annua population depended for its maintenance, at least in part, upon annual re-establishment from seeds, an event that overlapped with the senescing of flowering tillers in spring and early summer. Dense patches of A. stolonifera did not suppress P. annua germination but may have suppressed seedling establishment. (3) By comparison with other populations of P. annua and other grasses, seed production rates and seedling and tiller densities were high (e.g. 270 000 tillers m-2), but tiller life expectancy was short. Most tillers died without flowering. (4) A. stolonifera was the dominant component in summer and P. annua was dominant in winter. Seasonal changes in composition appear to be driven by the tillering capacity of one species relative to the other (i.e. by birth rates not death rates). (5) Most greens are subject to random, patchy disturbances. Since A. stolonifera has limited ability to colonize open areas, it is probably in these patches that P. annua initially establishes. The balance finally achieved between the companion species in any particular green may reflect the probability of disturbances occurring in that green.

Biology of Poa annua in a Temperate Zone Golf Putting Green (Agrostis stolonifera/Poa annua). II. The Seed Bank

(1) The seed bank of a golf green was monitored for 2 years by identifying germinants in core samples. (2) The seed populations contained twenty-four species of which only four occurred in the above-ground population. All species were abundant in the region and some were widespread. The main component of the seed bank was Poa annua. P. annua numbers fluctuated from a minimum of 30 000 seeds m-2 during autumn and winter, to a spring maximum of 210 000 seeds m-2. Agrostis stolonifera, with about 3000 seeds m-2, was the next most abundant species. (3) Most of the P. annua seed bank was transient and germinated during spring and early summer. The persistent part of the seed bank probably derived from the same plants that produced the transient population. Its persistence is attributed to dormancy enforced or induced by seed burial. (4) Much of the P. annua in the above-ground population was replaced annually from the transient seed bank. The persistent seed bank presumably enables P. annua to colonize any open areas created by disturbances in the green.

Physical Characteristics of Soil Mixtures Used for Golf Green Construction1

AbstractLarge amounts of money are invested each year in the preparation of mixtures for the construction of golf greens and athletic fields. Few efforts have been made to completely characterize the physical properties of the resulting greens. Therefore, a greenhouse experiment was conducted to determine the physical characteristics of a range of sand and soil mixtures for golf green construction. Treatment variables included the amount and texture of soil used in the mixture and the presence or absence of a sand layer between the mixture and the gravel drainage layer. The mixtures were placed in 30 cm diam. containers.They were compacted and grass was established. Infiltration rates decreased after the grass was established and decreased again after the soil mixture was compacted. Mixtures with greater than 3% clay had infiltration rates too small to assure a playable surface after heavy water applications. The depth of available water held by mixtures with 5% soil averaged 6.6 cm for a 35 cm layer. Pure sands held about half this amount of water. Measured water retention agreed well with that calculated from the unsaturated conductivity of the gravel layer and the water retention characteristics of the mixture. Provided the gravel used as the drainage layer has a particle distribution such that less than half the particles are greater than 0.64 cm, little evidence of particle migration was found even without a layer of sand between the mixture and the gravel. Optimum physical characteristics were achieved with mixture containing 5% soil, 85% sand, and 10% peat moss by volume.

Physical Properties of Hardwood Bark Growth Media1

Abstract Physical properties of various hardwood bark-soil mixes for containers were compared to a soil-peat-perlite mix. Bark-soil mixes containing a wide range of bark particle sizes were found to possess superior physical properties initially and remained satisfactory after a 13-month incubation period. However, bark-soil mixes were much less stable and deteriorated to a significantly greater extent. For golf greens, physical properties of hardwood bark or peat and soil and sand mixes were studied following compaction at 40 cm moisture tension. Initially, the bark mixes were superior and this was postulated to be due to a more uniform distribution of bark within the mixes. Based on the deterioration that occurred in bark-soil mixes for containers, it is concluded that use of hardwood bark in golf green mixes does not appear feasible.

Golf Green Research and the War

THE revised values which the war places upon various activities have caused the managers of the Board of Greenkeeping Research to review the position of the Research Station at St. Ives, Bingley, Yorks. The experimental plots at this centre have been built up over a period of eleven years, at a cost of more than £26,000, and have provided valuable new knowledge about the ecological interaction of plants grown in compact formation, and about the practical treatment of greens. Much of their scientific value lies in their long term of treatment, and it is gratifying to learn that they are to be carried on, even if the need for economies should curtail the Station's other activities. It is also useful to remember, in the present intensity of the war effort, that the Station has contributed to a fundamental understanding of grass ecology which could be applied to increase food production on some of the poorer grassland of British uplands. Its researches on pests and diseases of grassland could quickly be turned to the aid of agriculture, and the Station has further adapted itself to war conditions by working on the best methods of pasturing sheep on golf courses, and giving advice upon minimum upkeep during the present difficult times.

Greenkeeping Research

The Golf Green Research Station at St. Ives, Bingley, continues its investigations into problems connected with the management of lawns. Vol. 2, No. 7 of its journal has recently appeared, and contains articles on “The Management of Golfing Turf on Heavy Soil” by G. Samuels, “Mole Draining of Golf Courses on Heavy Land” by R. B. Dawson, “Composts and Fertilisers in Relation to Green—keeping” by T. W. Evans, “A Greenkeeper's Guide to the Grasses” by I. G. Lewis, and “Common Weeds of Turf” by R. B. Dawson. The Station has already made outstanding contributions to our knowledge of the ecology of the grasses which are used for lawns. Mr. R. B. Dawson and Dr. T. W. Evans have revolutionised our methods of manuring lawns, both of golf greens and garden and are substituting scientific knowledge for the ‘rule of thumb’ methods or the absence of methods, of the past. The journal may be obtained from the St. Ives Research Station, Bingley, Yorks., price 2s. 6d. per number.