As restrictions on water use, fertilization, and pesticide applications continue to increase, golf course superintendents will need to use grass species that require reduced inputs. The objective of this study was to evaluate alternative turfgrass species under low-input fairways conditions. In 2005, 17 species were established on native soil in St. Paul, MN. Each species was evaluated at three levels of traffic (zero, three, or six passes per week using a drum-type traffic simulator) and two mowing heights (1.90 and 2.54 cm). Data collected included turfgrass quality and percent living stand density. In 2006, velvet bentgrass (Agrostis canina L.), colonial bentgrass (Agrostis capillaris L.), and creeping bentgrass (Agrostis stolonifera L.) maintained acceptable quality in all treatment combinations. In 2007, Chewings fescue (Festuca rubra L. ssp. fallax) and sheep fescue (Festuca ovina L.) were the top-performing species regardless of treatment. Hard fescue (Festuca brevipila Tracey) performed poorly in Year 1 and well in Year 2. All other species did not perform at an acceptable level during the study. The results of this study indicate that sheep fescue, Chewings fescue, colonial bentgrass, and velvet bentgrass should be studied further for use on low-input golf course fairways in the northern United States.

Public attention is being increasingly focused on the environmental impact and management costs of turfgrass areas such as lawns for schools, parks, and homes. The objectives of this study were to: (i) identify grass species adapted to low‐input environments (limited water, no fertilizer or pesticides after establishment) in the North Central Region (NCR) of the USA; and (ii) evaluate these species for turfgrass quality under mowed and non‐mowed conditions. Low‐input turf trials of 12 grass species were established at eight locations and evaluated for turf quality over two years. Plots were mowed monthly at either 5.1 or 10.2 cm or not mowed. Hard fescue (Festuca brevipila Tracey), colonial bentgrass (Agrostis capillaris L.), tall fescue (Festuca arundinacea Schreb.), and sheep fescue (Festuca ovina L.) performed well at most locations at the 5.1 and 10.2‐cm mowing heights. Several other species were also evaluated: tufted hairgrass [Deschampsia cespitosa (L.) P. Beauv.], hybrid bluegrass (Poa arachnifera Torr. × Poa pratensis L.), meadow fescue [Schedonorus pratensis (Huds.) P. Beauv.], prairie junegrass [Koeleria macrantha (Ledeb.) Schult], crested wheatgrass [Agropyron cristatum (L.) Gaertn.], alkaligrass [Puccinellia distans (Jacq.) Parl.], blue grama [Bouteloua gracilis (Willd. Ex Kunth) Lag. Ex Griffiths], and crested dogstail (Cynosurus cristatus L.).

Turfgrass managers in the southeastern United States often overseed ‘Tifway’ bermudagrass [Cynodon transvaalensis Burtt‐Davey × C. dactylon (L.) Pers.] with perennial ryegrass (Lolium perenne L.) to provide a dense green turf during winter months. Although overseeding provides benefits, the spring transition from perennial ryegrass to bermudagrass can be troublesome and inconsistent. Perennial ryegrass may survive longer into the spring than is desired due to cool, wet conditions. The following experiment evaluated cultural methods for removal of perennial ryegrass from overseeded bermudagrass in the spring and early summer. The experiment was conducted at the North Carolina State University Turfgrass Field Center in Raleigh in the 1995 to 1996 and 1996 to 1997 growing seasons. Monocultures of ‘Gator’ and ‘Derby Supreme’ perennial ryegrass were overseeded into an established Tifway bermudagrass turf managed at golf course fairway conditions. It was hypothesized that various cultural treatments in the spring and summer could promote bermudagrass and/or discourage perennial ryegrass, and that the perennial ryegrass transition would differ depending on heat tolerance of the selected overseeding monocultures. The cultural treatments were biweekly vertical mowing, scalping, core cultivation, and vertical mowing/scalping, or two application timings of NH4NO3 Chemical removal of perennial ryegrass using pronamide [3,5‐dichloro‐N‐(1,1‐dimethyl‐2‐propynyl)benzamide] was included as a check treatment because it is commonly used to promote transition. Bermudagrass shoot density was consistently higher in nonoverseeded plots, illustrating perennial ryegrass competition. Cultural treatments affected perennial ryegrass cover during the spring and early summer but did not hasten its ultimate disappearance. Early or late applied NH4NO3 enhanced bermudagrass shoot density in both years. In contrast, plots receiving core cultivation had lower bermudagrass shoot density at the end of the transition period than the nontreated plots. Pronamide did hasten transition through 7 and 13 wk after initial treatment for 1996 and 1997, respectively. Regression analysis between natural perennial ryegrass disappearance over both years and air temperature or relative humidity indicates a significant association. This implies that cultural treatments alone may not consistently enhance natural transition of perennial ryegrass to bermudagrass.

in leachate on only one occasion, and total recovery amounted to 64 to 76% of the LFN applied. These au-Although the fate of fertilizer applied to turfgrass has been studied thors attributed the LFN loss to denitrification and in the past, recovery of applied fertilizer N is typically low, and denitrification has been cited as the reason. The objectives of this research NH 3 volatilization. were twofold: (i) to examine the fate of 15 N applied to Kentucky blue-Non-field and field studies to measure NH 3 volatilizagrass (Poa pratensis L.) turf as KNO 3 , including direct measurement tion from turf show extremely variable results, depending of denitrification; and (ii) to determine whether and how plants affect on the source of N, application rate, temperature, thatch fertilizer-N recovery. Polyvinyl chloride (PVC) cylinders, modified tothickness, irrigation and rainfall following application, permit atmospheric sampling, were used throughout field experiments and soil moisture (Volk, 1959;Nelson et al., 1980; during the spring and summer 1999 and a greenhouse experiment in Torello et al., 1983;Bowman et al., 1987;Titko et al., 2000. Potassium nitrate (98.5 atom % 15 N) was applied in solution at 1987). Bowman et al. (1987) applied 58 kg N ha Ϫ1 as 49 kg N ha Ϫ1 to replicated plots, and atmospheric samples were colurea to a Yolo loam soil (pH 7.3) under Kentucky bluelected three times a day from 0800 to 1100, 1100 to 1400, and 1400 to grass turf and measured volatilization following differ-1700 h during a 6-wk period in the spring and a 4-wk period during the summer of 1999. Emission of N 2 or N 2 O ranged from 3.3 to 21.3% ent irrigation treatments. Without irrigation, 36% of the and from 0.3 to 5.9% of labeled fertilizer N (LFN), respectively. Re-applied N volatilized, whereas volatilization was only covery of LFN in the soil or plant, plus that emitted as N 2 or N 2 O, 3% when 4.0 cm of irrigation was applied. One aspect ranged from 57.4 to 73.2%. A 4-wk greenhouse experiment comparing of a turfgrass system that will dramatically affect volatil-LFN recovery for bare soil and turf, including gas emission and leachization is the presence of thatch. Significant urease activate, was initiated in the summer of 2000. Total emission of LFN as ity, which hydrolyzes urea to NH 3 , occurs in the thatch N 2 or N 2 O was 19.0% for the turfgrass, as compared with 7.3% for layer (Bowman et al., 1987). Nelson et al. (1980) obthe bare soil. Corresponding values for total recovery of LFN were served that within 8 d following urea application to a 70.6 and 84.2%, respectively.Flanagan silt loam (fine, smectitic, mesic Aquic Argiudolls), 39% of the applied N volatilized as NH 3 from cores of Kentucky bluegrass containing ≈5 cm of thatch,