Applied Turfgrass Science最新文献

Cultivation and topdressing are commonly used methods to manage thatch/mat on creeping bentgrass (Agrostis stolonifera L.) golf greens. However, disruption caused by cultivation practices may adversely impact the playability of golf green surfaces. Thus, we undertook two studies to determine if sand topdressing color affects recovery from cultivation disruption of creeping bentgrass golf greens. Topdressing sand color treatments were black sand (BS) or tan sand (TS). Study 1 evaluated six cultivation methods and topdressing with TS or BS in 2008, 2009, and 2010. Plots were evaluated for total days disrupted (TDD) and mean days disrupted following cultivation (MDD). Topdressing with BS never resulted in more TDD than TS and decreased TDD for some cultivation treatments. Study 2 evaluated days to recover (DTR) following cultivation and topdressing with TS or BS at twelve aeration dates in 2008 and 2009. Black sand never resulted in more DTR than TS during any year and produced fewer DTR at one aeration date in 2008 and two aeration dates in 2009. We found that BS has potential to decrease recovery time following cultivation, but depends on cultivation timing and method. Optimizing cultivation timing, cultivation method, and topdressing sand, disruption time following cultivation can be reduced for creeping bentgrass putting greens in the Intermountain Pacific Northwest.

Longwood Gardens in Kennett Square, PA has a strong commitment to sustainability. All organic waste produced on site is either composted or treated and does not leave the property. Longwood's composting facility produces over 3500 cubic yards of compost, mulch and leaf mold per year. In order to use compost and compostable products effectively Longwood performs research in these areas.

Compost as a growing substrate component. Peat moss is the primary substrate component used in the greenhouse industry. The inherent pH of peatmoss can range from 3.0 to 4.0 and is typically increased to a suitable pH with the addition of limestone. Compost is a product that can also be used as substrate component and has a high inherent pH of 6.0 to 8.0. When using compost as a substrate component lime rates must be reduced or eliminated. The objective was to determine the resulting pH of substrates with varying amounts of limestone and compost. The experiment was a factorial design with five compost rates (0, 10, 20, 30, and 40% by volume), four limestone rates (0, 1.2, 2.4, and 3.6 g/liter substrate) with five replications. Three batches of each compost type were tested with this experimental design giving a total of 6 experiments. The substrate consisted of 25% pinebark, 5% calcine clay, 15% vermiculite, 15% perlite with the remaining 40% consisting of peat and/or compost based on the treatments. With 0 lime, initial substrate pH increased from 4.5 to 6.7 as compost rate increased. This trend occurred at all other lime rates, which had pH ranges of 5.2-6.9, 5.6-7.0 and 6.1-7.1 for rates of 1.2, 2.4, and 3.6 g/liter substrate, respectively. These data indicate substrate pH was significantly affected by both compost and lime treatments. Growers who use composts in their substrate mix will have to adjust lime rates accordingly to achieve the target pH.

Properties of biodegradable containers. Biodegradable containers fall into two categories: compostable, which are designed to be removed from the rootball before the final planting and plantable, which are designed to be left intact on the rootball and planted directly into the field, landscape bed or final container where roots will grow through the container walls. Longwood Gardens, Louisiana State University and University of Arkansas conducted research to determine several properties of these relatively new container types, which included peat, Fertil, Cowpots, coconut fiber, Strawpots, OP47, paper, rice hull and plastic (control). Plastic containers had the highest wall strength followed by paper containers, while peat, Cowpot and Fertil containers had the lowest wall strengths. Neither in the greenhouse or the landscape were there any significant trends on growth of vinca, geraniums or impatiens. After 8 weeks in the outdoor beds, Cowpot containers had the highest level of decomposition while Peat, Strawpot and Fertil containers had lower levels of decomposition. Furthermore, cocofiber container

Green roofs are considered among the best technological solutions for greening existing urban landscapes characterized by the lack of open and green spaces. The selection of the appropriate rootzone (vegetation layer) is of major importance since it needs to comply with several criteria such as: (a) providing sustainable growth of the selected plant material; (b) exercising limited weight on the building framework; (c) providing adequate anchorage depending on the type of the green roof (extensive-intensive); (d) consisting of environmentally friendly materials; (e) prohibiting any environmental hazards such as nutrient or agrochemical leaching; (f) quickly draining excess water yet retaining increased moisture.

Up to date the green roof industry has mainly been following the German guidelines (FLL) for green roofs while other countries have completely or partially accepted them. However the FLL guidelines have been formulated for northern climates and demand alterations for being applicable to semi-arid or Mediterranean type climatic conditions. In addition the formulaic categorization of green roofs as extensive, semi-intensive and intensive has recently received criticisms in an effort to proceed in an adaptive green roof approach that would depend on the local conditions of each urban environment.

Rootzone type, substrate depth and plant species selection are the most important factors contributing to the success and sustainability of a green roof system. The green roof rootzones are mainly constituted by inorganic and at a much lesser degree by organic materials. The most commonly utilized inorganic materials as rootzone constituents are pumice, crashed tile or brick, expanded shale or clay, sand, and zeolite whereas for the organic materials peat and composts.

There is a worldwide research that has provided significant information concerning the effects of different types of green roof rootzones combined with different substrate depths and with various plant species. Several plant species with C₃, C₄ or CAM metabolic pathways have been evaluated and the conditions of their sustainable growth have been determined. It has been acknowledged that rootzone depth has a significant role in green roof flora sustainability since in most cases increasing the rootzone depth has resulted in increasing plant survival and sustainability and contributed to water inputs reduction. Conversely plants have differentiated reactions in regards to rootzone type since they seem to have different inherited preferences for inorganic constituents, organic content and in several cases their behavior has been altered between growing periods (water stressed and unstressed conditions). So far the effort has been focused on utilizing native and endemic plant species to reintroduce the lost flora and fauna in contemporary cities. However there is also an effort to increase the selection palette of plant species by utilizing an ad

Green roofs consist of overlapping layers that function as waterproofing, root barrier, drainage, substrate, and vegetation. Substrate components are designed to be relatively light weight, to resist degradation, and to drain rapidly. Physical characteristics must meet industry standards (FLL Guidelines, 2002) with water retention determined using 15 × 16.5 cm (diameter × height) cylinders (cyl) containing ∼1766.3 cm³ of substrate. However, green roofs may have a depth as shallow as 4 cm and slopes that affect water-holding properties; thus, a single protocol may be insufficient. Research on green roof physical properties of substrates is lacking. In this study, we evaluated the physical characteristics of a green roof substrate using three different containers. Also, physical characteristics were determined for a preexisting green roof. Particle size distribution was determined by screening using three air-dried 100 g samples of green roof substrate placed into the top of a sieve series with mesh diameters of 9.5, 4.0, 2.0, 1.0, 0.5, and 0.053 mm followed by shaking for three minutes in a Ro-Tap shaker. Physical properties were determined at 0 kPa and following applied suction pressure (6.3 kPa) using methods of Spomer (1990) and FLL (2002). To determine substrate physical properties, Buchner funnels with removable 17 × 16.5 cm-cyl or 13 × 6.8 cm-cyl (diameter × height) were filled with 2835.8 cm³ or 902.1 cm³ of substrate, respectively. Bulk density, total porosity (TP), maximum water-holding capacity (∼container capacity [CC]), aeration porosity (AP), and AP_{-6.3 kPa} were determined. A rectangle (rec)-shaped container (∼15 × 17 × 7 cm; width × length × height) was filled with 1158.9 cm³ of substrate directly from an existing green roof (Temple University, Ambler, PA) or from prepared substrate and, subsequently, physical characteristics were determined at an approximate 13.5° slope. There were three replicates per treatment (container type). Prepared substrate consisted of heat-expanded clay with a composition of 40:50:10 fine grade:medium grade:compost. Temple University's green roof consisted of a mixture of more than one component and has supported healthy Sedum, Allium, and Dianthus genera for several years.

Substrate composition and container shape had a significant impact on physical property determinations. There were no differences for TP, CC, or AP between 17 × 16.5 cm-cyl and 13 × 6.8 cm-cyl or ∼15 × 17 × 7 cm-rec. However, TP differed between 13 × 6.8 cm-cyl (TP=38.1%) and ∼15 × 17 × 7 cm-rec (TP=45.7%). Physical characteristics on a healthy green roof were 55.8%, 49.6%, and 6.2% for TP, CC, and AP, respectively, and within FLL standards for container capacity. Particle sizes of both prepared substrate and substrate on Temple University's green roof were within FLL standards; however, the later substrate had higher TP and CC than other treatments. Ex

Introduction. Increased economic and environmental concerns have caused many golf courses to re-assess turf management strategies so that inputs and costs are minimized, while golfer expectations are still met. However, there are currently no soil nutrient guidelines that specifically address this growing need. In this study, PACE Turf and the Asian Turfgrass Center pooled soil test data collected over the past 20 years that has all been analyzed by a single laboratory -- Brookside Laboratories, New Knoxville OH. The data was analyzed to determine the minimum level of each key soil nutrient that would sustain acceptable turf growth and quality. The non-negative log-logistic distribution provided a significant fit for all parameters using Kolmogorov Smirnov goodness of fit. The nutrient level that coincides to the 10th percentile (p(x) = 0.1, or 10% of the samples report lower values than x) using the best fit log-logistic distribution was used to define the Minimum Level for Sustainable Nutrition (MLSN) for each nutrient.

Methods. Data for analysis were selected from the PACE Turf database of more than 16,000 individual soil samples. In order to identify minimum nutrient guidelines, only soils with cation exchange capacities (calculated by summation of Mehlich-3 extracted cations) of less than 6 cmol/kg and soil pH between 5.5 and 7.5 were included in the analysis. Olsen phosphorus guidelines were developed for soils reporting a pH greater than 7.5. Data were analyzed using EasyFit distribution-fitting software from Mathwave (www.mathwave.com) and the three-parameter log-logistic distribution was used to identify the MLSN guidelines.

Results. The table below reports the Minimum Levels for Sustainable Nutrition (MLSN) for each soil nutrient, and the values for alpha, beta and gamma for the three-parameter log-logisitc fit provided by EasyFit software.