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The objective of this experiment was to determine the suitability of a compost obtained from a commercially available solid-waste processing plant for sod production when placed over a plastic barrier. Comparisons were made between compost-grown sod with and without fertilizer and between compost-grown sod and commercially grown sod. Six weeks after seeding or sprigging, both fertilized and nonfertilized compost-grown `Argentine' bahiagrass (Paspalum notatum Flugge), `Tifway' bermudagrass (Cynodon transvaalensis × C. dactylon), and `Floratam' St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze.] had discolored leaf blade tissue and poor growth. At 6 weeks, bahiagrass leaf tissue had a low N concentration, which suggested that the compost immobilized fertilizer N. Additionally, initial high salinity of the compost (2.85 dS·m-1) may have contributed to turf discoloration and lack of vigor. However, poor growth and discoloration were temporary. At 3 and 5 months, fertilized compost-grown turfgrasses had higher quality and coverage than nonfertilized sod. At 5 months, fertilized sod had sufficient coverage for harvest, whereas for conventional field production 9 to 24 months generally is required to produce a harvestable product. Compost-grown sod pieces had similar or higher tear resistance than commercially grown sod. One and 3 weeks after transplanting on a sand soil, compost-grown sod produced higher root weight and longer roots in the underlying soil than did commercially grown sod. The solid-waste compost used in this study offers a viable alternative material for producing sod that will benefit solid-waste recycling efforts.
Field and laboratory studies were conducted to evaluate the K retention properties of several resin-coated (RC), sulfur-coated (SC), and plastic-coated (PC) K fertilizers. Substantial differences in K release were found among the controlled-release K materials, based both on the K content of `Tifgreen' bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burt-Davvy] clippings and on direct measurement of K remaining in fertilizer granules in the field over time. One SC material appeared to release K too rapidly, and one RC material appeared to release K too slowly to be useful for providing extended plant-available K to turfgrass. The other sources appeared to have release characteristics that would be favorable for turfgrass maintenance. Because differences in K release were observed among the sources, a laboratory method for assessing K release would be useful. Toward this-end, models were developed relating K retention of sources in hot water (70C) to K retention under field conditions.
Soil-water repellency is often a problem for turfgrass grown on sand soils. Wetting agents used to alleviate repellency often provide mixed results. We evaluated AquagroL and an experimental material (ACA 864) at 0, 7, 14, and 21ml/m2 applied monthly to tifgreen bermuda grown on a soil-water repellent Margate fine sand over 6 months. Alleviation of repellency was based upon water drop penetration time (WDPT). Wetting agents did not effect turf quality, cover, or discoloration. Wetting agents did not reduce repellency 1 month after initial application. At 2 months, ACA 864 at 21ml/m2 significantly reduced WDPT. With repeat applications, lower rates of ACA 864 provided reductions in WDPT similar to the highest rate of ACA 864, suggesting an additive effect over time. There was a decline in WDPT for all wetting agent treatments, except the control, over time. Repellency decreased with soil depth, and repeat wetting agent application reduced WDPT at lesser depth.
For only the second time, the United States will host The International Turfgrass Society's (ITS) International Turfgrass Research Conference (ITRC). The VII ITRC will be held July 18-24, 1993 at The Breakers in Palm Beach, FL. Since its inception, the ITS has been devoted to addressing problems that effect turfgrass and improving the standards of turfgrass science through international communication. The Conference will offer two symposia entitled “Pesticide and Nutrient Fate in Turfgrass Systems” and “Quantification of Surface Characteristics of Sports Fields”. Additionally plenary and volunteered oral and poster presentations on all topics of turfgrass science and related horticultural landscape management tours of the local horticultural industries will be offered. Volunteered papers will be published in a proceedings as either original research papers or as technical papers. Papers submitted as original research will undergo refereed peer review prior to acceptance. See poster for further details or contact authors at above address (phone: 305-475-8990).
Current interest in the fate of agrochemicals applied to turf is encouraging many turf scientists to contemplate renovation of existing field plots for soil-water monitoring studies. Ceramic cup samplers are used for these studies and result in little soil profile disturbance. However, a limitation to using this tool is frequent sampler failure caused by frequent system air leaks. Also, conventional installation and sampling require that samplers be accessible from above the soil line. This imposes a constraint on turf maintenance and increases traffic and wear to turf plots. Herein, an inexpensive offsite soil-water sampling method using permanently installed ceramic cup samplers that allows for routine turf maintenance without system failure is described. Thirty-six separately irrigated 4 m2 plots each with an installed sampler provided daily data over 1988-1989, from which the effects of a range of irrigation, N, K, and propoxur treatments on soil-water concentrations were evaluated. These data, plus calculated percolation provided an estimate of groundwater loading.
Ultraviolet (UV) radiation poses a potential stress for plant growth and development due to its effect on photosynthesis and plant productivity. In the northern hemisphere, peak UV radiation exposure is predicted to occur from 2010 to 2020, with reduced color from UV-related injury, a possibility for turfgrasses. The objective of this study was to investigate the effects of ultraviolet-B (UV-B) light on turfgrass growth and morphology in three cool-season grasses. Cultivars Barvado tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.], Penncross and L-93 creeping bentgrass (Agrostis stolonifera L.), and Barlenium perennial ryegrass (Lolium perenne L.), were selected because of limited information on their growth and development in elevated UV conditions at heights of cut above 10 cm. The impact of UV-B light treatment on color, relative growth rate, and tillering was measured over a 4-week period in repeated experiments. Ultraviolet-B radiation levels were measured at 16 kJ·m−2·d−1 biologically effective UV-B light in growth chambers programmed for a day/night regime of 14/10 hours. Chamber temperatures were maintained at 20 °C day/17 °C night. Ultraviolet-B light significantly inhibited tiller production in the first experiment in all grasses except PR, whereas no grasses were inhibited in the second experiment. Relative growth rates in all grasses were significantly lower in UV-B conditions 3 weeks after treatment initiation. Turfgrasses exposed to this level of UV-B light at typical lawn heights-of-cut had lower color ratings compared with the non-UV-B-treated control at 2 weeks after treatment initiation. The experiments demonstrated that exposure to UV-B resulted in a decline of growth rate and color in cool-season turfgrasses within a timeframe of 2 weeks. Coarse-textured turfgrasses [tall fescue (TF)/perennial ryegrass (PR)] may be more adapted to higher UV-B conditions due to morphological differences compared with the finer textured varieties [creeping bentgrass (CB)].
Urban watersheds include extensive turfgrass plantings that are associated with anthropocentric attitudes toward landscapes. Native and construction-disturbed urban soils often cannot supply adequate amounts of nitrogen (N) and phosphorus (P) for the growth and beauty of landscape plants. Hence, fertilization of landscape plants is practiced. Mismanaged fertilization and irrigation practices represent a potential source of nutrients that may contribute to water quality impairment. This review focuses on turfgrass fertilization practices and their impacts on urban water quality. Research results show that fertilization during active growth periods enhances turfgrass nutrient uptake efficiencies. The major concern regarding the fertilization of turfgrass and landscape plants in urban watersheds, therefore, is selecting the proper combination of fertilizer rate, timing, and placement that maximizes nutrient utilization efficiency and reduces the risk for nutrient loss to water bodies. Encouraging individuals to adopt best management practices (BMPs) is a priority for watershed managers. Research has found that educational programs are an important part of changing fertilization habits and that education needs to be thorough and comprehensive, which is beyond the scope of many seminars and fact sheets currently in use.
Urban water quality management is becoming an increasingly complex and widespread problem. The long-term viability of aquatic ecosystems draining urban watersheds can be addressed through both regulatory and nutrient and water management initiatives. This review focuses on U.S. regulatory (federal, state, and local) and management (runoff, atmospheric deposition, and wastewater) impacts on urban water quality, specifically emphasizing programs in Florida. Because of rapid population growth in recent decades, and projected increases in the future, appropriate resource management in Florida is essential. Florida enacted stormwater regulations in 1979, before the U.S. Environmental Protection Agency (USEPA) amended the Clean Water Act (CWA) to regulate stormwater discharges. However, in the United States, more research has been conducted on larger structural best management practices (BMPs) (e.g., wet ponds, detention basins, etc.) compared with smaller onsite alternatives (e.g., green roofs, permeable pavements, etc.). For atmospheric deposition, research is needed to investigate processes contributing to enhanced deposition rates. Wastewater (from septic systems, treatment plants, and landfills) management is especially important in urban watersheds. Failing septic systems, elevated nutrient concentrations in discharged effluent, and landfill leachate can all potentially degrade water quality. Proposed numeric nutrient criteria from the USEPA and innovative technologies such as bioreactor landfills are emergent regulatory and management strategies for improved urban water quality.