Turfgrass Species Research Articles

Salt-Induced Damage is Alleviated by Short-Term Pre-Cold Treatment in Bermudagrass (Cynodon dactylon).

Excess salinity is a major environmental stress that limits growth and development of plants. Improving salt stress tolerance of plants is important in order to enhance land utilization and crop yield. Cold priming has been reported to trigger the protective processes in plants that increase their stress tolerance. Bermudagrass (Cynodon dactylon) is one of the most widely used turfgrass species around the world. However, the effect of cold priming on salt tolerance of bermudagrass is largely unknown. In the present study, wild bermudagrass was pre-treated with 4 °C for 6 h before 150 mM NaCl treatment for one week. The results showed that the cell membrane stability, ion homeostasis and photosynthesis process which are usually negatively affected by salt stress in bermudagrass were alleviated by short-term pre-cold treatment. Additionally, the gene expression profile also corresponded to the change of physiological indexes in bermudagrass. The results suggest that cold priming plays a positive role in improving salt stress tolerance of bermudagrass.

Comparative proteomic analysis provides new insights into the specialization of shoots and stolons in bermudagrass (Cynodon dactylon L.)

BackgroundBermudagrass (Cynodon dactylon L.) is an important turfgrass species with two types of stems, shoots and stolons. Despite their importance in determining the morphological variance and plasticity of bermudagrass, the intrinsic differences between stolons and shoots are poorly understood.ResultsIn this study, we compared the proteomes of internode sections of shoots and stolons in the bermudagrass cultivar Yangjiang. The results indicated that 376 protein species were differentially accumulated in the two types of stems. Pathway enrichment analysis revealed that five and nine biochemical pathways were significantly enriched in stolons and shoots, respectively. Specifically, enzymes participating in starch synthesis all preferentially accumulated in stolons, whereas proteins involved in glycolysis and diverse transport processes showed relatively higher abundance in shoots. ADP-glucose pyrophosphorylase (AGPase) and pyruvate kinase (PK), which catalyze rate-limiting steps of starch synthesis and glycolysis, showed high expression levels and enzyme activity in stolons and shoots, respectively, in accordance with the different starch and soluble sugar contents of the two types of stems.ConclusionsOur study revealed the differences between the shoots and stolons of bermudagrass at the proteome level. The results not only expand our understanding of the specialization of stolons and shoots but also provide clues for the breeding of bermudagrass and other turfgrasses with different plant architectures.

Salinity Tolerance and Recovery Attributes of Warm-season Turfgrass Cultivars

As population growth places greater pressures on potable water supplies, nonpotable recycled irrigation water is becoming widely used on turfgrass areas including golf courses, sports fields, parks, and lawns. Nonpotable recycled waters often have elevated salinity levels, and therefore turfgrasses must, increasingly, have good salinity tolerance to persist in these environments. This greenhouse study evaluated 10 commonly used cultivars representing warm-season turfgrass species of bermudagrass (Cynodon spp.), zoysiagrass (Zoysia spp.), st. augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze], and seashore paspalum (Paspalum vaginatum Swartz) for their comparative salinity tolerance at electrical conductivity (EC) levels of 2.5 (control), 15, 30, and 45 dS·m–1. Salinity treatments were imposed on the grasses for 10 weeks via subirrigation, followed by a 4-week freshwater recovery period. Attributes, including turf quality, the normalized difference vegetation index (NDVI), canopy firing, and shoot biomass reductions were evaluated before and after salinity stress, as well as after the 4-week freshwater recovery period. Results showed considerable differences in salinity tolerance among the cultivars and species used, with the greatest tolerance to elevated salinity noted within seashore paspalum cultivars and Celebration® bermudagrass. In comparison with growth in 2.5-dS·m–1 control conditions, increased shoot growth and turf quality were noted for many bermudagrass and seashore paspalum cultivars at 15 dS·m–1. However, st. augustinegrass and some zoysiagrass cultivars responded to elevated salinity with decreased growth and turf quality. No cultivars that had been exposed to 30- or 45-dS·m–1 salinity recovered to acceptable levels, although bermudagrass and seashore paspalum recovered to acceptable levels after exposure to 15-dS·m–1 salinity. More severe salinity stress was noted during year 2, which coincided with greater greenhouse temperatures relative to year 1.

Effects of isolates of Clarireedia jacksonii and Clarireedia monteithiana on severity of dollar spot in turfgrasses by host type

Dollar spot, caused by four Clarireedia species (formerly Sclerotinia homoeocarpa), is a devastating disease that affects many turfgrass species throughout North America. Proper classification and genetic diversity of Clarireedia spp. was debated for the past several decades until recently when the organism was reclassified in 2018. Previous studies have shown that there is little genetic diversity except for isolates obtained from warm season hosts in Florida and the southern United States. Our research confirms the presence of isolates obtained from cool-season (C3) turfgrass species which are consistent with the recently classified species Clarireedia jacksonii; and a second, distinct sub-group of isolates obtained solely from warm-season (C4) turfgrass species, which are consistent with the recently classified species Clarireedia monteithiana. Additionally, we have documented the coexistence of these two species throughout the transition zone of the United States, extending as far north as Virginia, with both species present among adjacent stands of C3 and C4 turfgrass species in the same locale. Despite previous documentation of genetically distinct isolates occurring in the United States, there have been no reports on the variability in growth of the two named species over a range of temperatures, nor have these species been evaluated for their ability to infect both C3 and C4 turfgrass species. The effects of temperature on the lack of in vitro isolate growth for both C. jacksonii and C. monteithiana isolates were most noticeable at 10 and 35 °C, where all isolates exhibited little to no growth after 60 h. Cross inoculation experiments showed that both species are capable of infecting and inciting disease on both the preferred and alternative host, and that C. jacksonii isolates are more virulent on both C3 and C4 host grasses than C. monteithiana isolates. The results of this study will have implications for dollar spot management strategies on bermudagrass as well as an increased need for turfgrass breeders to develop dollar spot resistance cultivars of bermudagrass, particularly for those used in climates extending north of the transition zone.

Drought-induced injury is associated with hormonal alteration in Kentucky bluegrass

ABSTRACTPlant hormones play an important role in plant adaptation to abiotic stress, but hormonal responses of cool-season turfgrass species to drought stress are not well documented. This study was to investigate responses of hormones and photosynthesis to drought stress and examine if drought stress – induced hormone alteration is associated with stress tolerance in kentucky bluegrass (KBG, Poa pratensis L.). The grass was grown in a growth chamber for 6 weeks and then subjected to drought stress [40%-50% evapotranspiration (ET) replacement)] for 28 d. Drought stress caused cell membrane damage, resulting in decline in photosynthetic rate (Pn), chlorophyll content, and visual quality in KBG. Drought stressed grass had higher leaf abscisic acid (ABA), lower leaf trans-zeatin riboside (ZR), isopentenyl adenosine (iPA), and indole-3-acetic acid (IAA), but similar level of leaf gibberellin A4 (GA4) when compared to the control (well-watered). On average, drought stress treatment reduced leaf ZR by 59.1%, iPA by 50.4%, IAA by 26.7%, while increased ABA by 108.5% when compared to the control at the end of drought stress (28 d). The turf quality and photosynthetic rate was positively correlated with cytokinins and IAA, but negatively correlated with ABA and ABA/cytokinins (CK) ratio under drought stress. The results of this study suggest drought stress-induced injury to Kentucky bluegrass may be associated with hormonal alteration, and the plants with higher cytokinins and IAA and less ABA under drought stress may have better photosynthetic function and performance.

Energetic Aspects of Turfgrass Mowing: Comparison of Different Rotary Mowing Systems

Turfgrass mowing is one of the most important operations concerning turfgrass maintenance. Over time, different mowing machines have been developed, such as reel mowers, rotary mowers, and flail mowers. Rotary mowers have become the most widespread mowers for their great versatility and easy maintenance. Modern rotary mowers can be equipped with battery-powered electric motors and precise settings, such as blade rpm. The aim of this trial was to evaluate the differences in power consumption of a gasoline-powered rotary mower and a battery-powered rotary mower. Each mower worked on two different turfgrass species (bermudagrass and tall fescue) fertilized with two different nitrogen rates (100 and 200 kg ha−1). The battery-powered mower was set at its lowest and highest blade rpm value, while the gasoline-powered mower was set at full throttle. From the data acquired, it was possible to see that the gasoline-powered mower had a much higher primary energy requirement, independent of the turf species. Moreover, comparing the electricity consumption of the battery-powered mower over time, it was possible to see that the power consumption varied according to the growth rate of both turf species. These results show that there is a partial waste of energy when using a gasoline-powered mower compared to a battery-powered mower.

Effects of Sub-Optimal Temperatures on Seed Germination of Three Warm-Season Turfgrasses with Perspectives of Cultivation in Transition Zone

Warm-season turfgrass species prevail in tropical and subtropical areas, but can also be grown in the transition zone. In this case, cold tolerance is a key aspect for germination and successful turfgrass establishment. The germination response to sub-optimal temperatures was investigated for Cynodon dactylon (cvs Jackpot, La Paloma, Transcontinental, Yukon, Riviera), Buchloe dactyloides (cv SWI 2000) and Paspalum vaginatum (cv Pure Dynasty). Four temperature regimes were applied, i.e., 20/30 °C, 15/25 °C, 10/20 °C and 5/15 °C, with a 12:12 h (light:dark) photoperiod. Germination assays were performed twice, with six replicates (Petri dishes) per treatment in each experiment, fifty seeds per dish. The final germinated percentages at last inspection time (FGP) were obtained for each Petri dish and processed by using a generalized linear mixed model (binomial error and logit link). Germination curves were fitted to each Petri dish by using time-to-event methods and germination rates (GR) for the 10th, 20th and 30th percentiles were derived and used to fit a linear thermal-time model. For all cultivars, FGP decreased with decreasing mean daily temperatures. Base temperatures (Tb) ranged between 11.4 °C and 17.0 °C, while the thermal time to obtain 30% germination ranged from 51.3 °C day for SWI 2000 to 144.0 °C day for Pure Dynasty. The estimated parameters were used to predict germination time in the field, considering the observed soil temperatures in Legnaro. The estimated date for the beginning of germination in the field would range from early April for SWI 2000 and Transcontinental to mid-May for Riviera. These results might be used as a practical support for planning spring sowing, which is crucial for successful turfgrass establishment, especially without irrigation.

Strengths and limitations of Bacillus thuringiensis galleriae for managing Japanese beetle (Popillia japonica) adults and grubs with caveats for cross-order activity to monarch butterfly (Danaus plexippus) larvae.

Target-selective biopesticides are needed to facilitate integrated pest and pollinator management in urban landscapes and gardens. Bacillus thuringiensis galleriae, strain SDS-502 (Btg), recently registered in the USA and Canada, produces Cry8Da protein active against scarab beetles. We evaluated Btg formulations for managing the Japanese beetle [Popillia japonica Newman (JB)], a polyphagous invasive pest, including residual spray effectiveness for reducing adult feeding on Rosa and Tilia spp., and granular formulations for early- or late-curative control of root-feeding grubs in turfgrass. We also tested for cross-order activity to monarch butterfly (Danaus plexippus L.) larvae and other non-target insects. Field-weathered Btg residues reduced JB feeding on foliage for 3-14 days. Most beetles were still flight-capable after 24 h confinement with Btg-treated leaves. Granular Btg failed to control early- or late-instar JB grubs in soils under several turfgrass species at multiple field sites. In three trials, feeding on Btg-sprayed milkweed resulted in 97-100% mortality of early instar monarchs, with symptoms of B. thuringiensis pathogenesis. Fall armyworms (Spodoptera frugiperda (J.E. Smith)) fed Btg-treated grass had reduced body mass, but there were no adverse effects on lady beetle larvae preying on Btg-sprayed aphids or on the aphids themselves. This study supports efficacy of Btg strain SDS-502 for reducing defoliation by adult JB in urban landscape settings. Granular formulations, however, failed to control JB grubs in turfgrass soils. Btg should not be used in gardens with larval host plants of the monarch butterfly or other non-pest Lepidoptera, especially species of conservation concern. © 2019 Society of Chemical Industry.

Stimulation of Growth and Alteration of Hormones by Elevated Carbon Dioxide for Creeping Bentgrass Exposed to Drought

ABSTRACTDrought stress inhibits shoot growth of cool‐season turfgrass species, and elevated CO2 concentration may mitigate the adverse effects of drought through alteration of hormone production. The objective of this study was to determine whether elevated CO2–enhanced drought tolerance in creeping bentgrass (Agrostis stolonifera L.) was associated with the stimulation of tiller and stolon growth and the alteration of stress‐regulating and growth‐regulating hormone accumulation. Creeping bentgrass (cv. Penncross) plants were established for 24 d at ambient (400 μL L−1) or elevated (800 μL L−1) CO2 concentration and subsequently exposed to drought stress for 23 d by withholding irrigation. Drought stress caused significant reduction in leaf relative water content and tiller density, whereas both parameters, as well as stolon length, were maintained at significantly higher values in CO‐treated plants compared with those at ambient CO2 under drought stress. The positive effects of elevated CO2 on the maintenance of leaf hydration and the promotion of tiller density and stolon growth in creeping bentgrass exposed to drought stress could be associated with the suppression of drought‐induced accumulation of abscisic acid and the increase in the endogenous content of isopentenyladenosine, jasmonic acid, and the jasmonic acid precursor 12‐oxo‐phytodienoic acid. These results suggest that the elevated CO2–enhanced growth of tillers and stolons in creeping bentgrass under drought stress could be regulated in part by the adjustment of endogenous hormone levels.

Physiological responses and accumulation characteristics of turfgrasses exposed to potentially toxic elements

The tolerance and enrichment of potentially toxic elements (PTEs) in plants are the most important basis of phytoremediation technology for mining area soils. The aim of this research was to study PTEs tolerance, translocation and accumulation differences in three turfgrass species and the biochemical changes of plants and soils. Three turfgrass species were cultured on soils contaminated by single and compound PTEs. Pb, Zn, Cd and As concentrations and biochemical indicators in plant (root and shoot) and soil were determined. Moreover, the microbial communities in rhizosphere soil were analyzed. The studied plants showed strong tolerance and high enrichment ability to Pb, Zn, Cd and As in soil under different PTE concentration gradient stress. Festuca arundinacea had the strongest tolerance to PTEs, whereas Medicago sativa L. had the best tolerance to PTEs. Among all the measured growth or biochemical indicators, the relative growth rate and enzymatic activity of Orychophragmus violaceus were most sensitive to stress. The bioconcentration and translocation factors of Medicago sativa L. for Cd were 1.60 and 1.17, respectively, indicating that it was the most suitable plant for extracting Cd. Compared with other plants, Festuca arundinacea had the most significant effect on soil environment improvement, increasing the soil enzyme activities and microbial community after phytoremediation. This study indicates that Medicago sativa L. can be a potential phytoextraction plant to remove Cd, whereas Festuca arundinacea is more suitable as a cover plant to prevent the dispersion of contaminants in polluted soil.

Effect of humic acid and mulches on characteristics of tall fescue (Festuca arundinacea Schreb.)

Application[Editor 321] of biotic growth regulators (e.g. humic components) and appropriate mulches is recommended to improve turfgrass quality especially in arid andsemi-arid climate zones. However, limited number of studies have investigated their effect on lawn establishment. To investigate the effect of humic acid (HA) and selected mulches on characteristics of Festuca arundinacea in its planting stage, a factorial experiment based on a completely randomized block design with three replications was performed. The first factor was mulch types including vermicompost, leaf compost, cow manure,[Editor 322] and sand (control) which were used to cover the seeds. The second factor was a HA solution (100 ml l-1) sprayed monthly over the period of the experiment. Plant height, fresh and dry weight of lawn clippings, photosynthetic index, leaf texture, and overall turfgrass quality were measured. Spraying HA significantly improved the measured factors except the dry weight and photosynthetic index of the plants. Among the mulches, vermicompost provided better impressions on improving the characteristics of this turfgrass species including 48% increase in fresh weight, 18% increase in height, 48% increase in total quality, and 10% reduction in leaf width of the turfgrass. This research can assist in developing knowledge for having high quality lawns in urban landscapes of arid and semi-arid environments.

Twolined Spittlebugs in Turfgrass

Spittlebugs are present throughout the entire state, but they are more abundant in northern and northwestern Florida. They attack all turfgrass species, but centipedegrass is the most susceptible. Adults also feed on ornamental plants, especially hollies (Ilex cassine or I. opaca). This document is ENY-334, one of a series of the Department of Entomology and Nematology, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Date first printed October 1993. Revised: September 2005.

Biology and Management of Doveweed (Murdannia nudiflora) in Ornamental Crop Production

Doveweed is a common grass-like warm-season annual weed in Florida landscapes, container nurseries, and other agricultural production systems. This article is written for green industry professionals and others to aid in the identification and management of doveweed in and around ornamental plants. Information on doveweed management in warm-season turfgrass species can be found at https://edis.ifas.ufl.edu/pdffiles/AG/AG39500.pdf.

Turfgrass Species Affect the Establishment and Bloom of Kura Clover (Trifolium ambiguum) in Lawns

Lawns represent one of the largest cultivated areas in urban landscapes, and in the Upper Midwest of the United States, lawns are typically composed of a small number of cool-season turfgrass species. There is increased interest in enhancing areas dedicated to lawns using flowering species for conservation purposes—for example, to support pollinators. In this study we used a model flowering forb, Kura clover (Trifolium ambiguum M. Bieb.), because—like many flowering species of conservation interest—it is slow to establish and is sensitive to grass competition. We varied the Kura clover seeding rate into four different turfgrass species treatments: kentucky bluegrass (Poa pratensis L.), hard fescue (Festuca brevipila Tracy), tall fescue [Schedonorus arundinaceum (Schreb.) Darbysh.], and perennial ryegrass (Lolium perenne L.) in two separate trials. Establishment and bloom of Kura clover was significantly greater in trial 1 for kentucky bluegrass and hard fescue than tall fescue and perennial ryegrass. In trial 2, Kura clover established significantly greater in kentucky bluegrass compared with tall fescue and perennial ryegrass, whereas Kura establishment in hard fescue was not significantly different from the other treatments. The seeding rate of Kura clover did not affect establishment in either trial. The results from this study suggest kentucky bluegrass and hard fescue are promising turf companion grasses for future forb/turf interseeding research.

Inter-morphotype hybridization in tall fescue (Festuca arundinacea Schreb.): exploration of meiotic irregularities and potential for breeding

The Continental morphotype of tall fescue is one of the main forage and turf grass species. However, it suffers from summer drought, especially in dry and hot climates. On the other hand, the Mediterranean morphotype of tall fescue display summer dormancy. Hybridization of the two morphotypes seems to be an efficient way to introgress summer dormancy from Mediterranean morphotypes into elite cultivars of the Continental morphotype. In this study, we performed a series of reciprocal crosses producing F1 hybrids. Phenotyping revealed heterosis for plant height, fresh weight and dry matter yield, with hybrids generally outscoring parental genotypes. On the other hand, F1 hybrids had reduced fertility and lower seed set. This was a consequence of meiotic irregularities. Both parental morphotypes carry chromosome pairing regulators responsible for diploid-like behavior in meiosis. However, it is clear from this study that the regulators from the two morphotypes are not compatible. We observed high frequency of multivalent formation and homoeologous chromosome pairing in F1 hybrids. Molecular and cytogenetic analyses indicate high level of genome differentiation between both morphotypes. This might be caused either by massive genome reshuffling during the evolution or, most likely, by origination of the two morphotypes from different parental species. As such, introgression-form of breeding involving several rounds of backcrosses resulting in the restoration of chromosome pairing regulator (at least in some plants) appears to be the only way to achieve stability of the hybrid genomes and thus, wider utilization of genetically stable and fertile hybrid tall fescue for forage and turf.

Effects of close cutting on ground cover and quality of a polystand of Manilagrass and cool season turfgrasses

Warm season turfgrasses can be grown successfully in the transition zone, but dormancy occurs to some extent during the winter. Overseeding with cool-season turfgrasses is necessary if winter dormancy of warm season turfgrasses is not tolerated. The increasing availability of zoysiagrass cultivars has enabled this genus to be considered suitable for low-maintenance golf courses, especially for golf tees and golf fairways. On the other hand, zoysiagrasses have the most rigid leaves of all turfgrass species, followed by bermudagrasses and by the other warm season turf species. Thus, to have a high mowing quality, mowers working constantly on zoysiagrasses require more sharpening than mowers working on other grasses. Rotary mowers are not suitable for mowing at low heights and often result in scalping, while reel mowers perform optimal mowing at a short height (below 2.5 cm) but require accurate management and frequent sharpening. Autonomous mowers have proven to produce a superior turf quality compared with traditional walk-behind rotary mowers, but no autonomous mower has ever been tested at a low mowing height on an overseeded warm season turfgrass. Because of this, the trial was carried out to simulate a golf tee overseeded with cool season turfgrasses, with low input fertilisation rates and with one of the most difficult turf species to mow; i.e. Zoysia matrella (L.) Merr. The trial was carried out in San Piero a Grado (Pisa, Italy) from October 2016 to October 2018. After a two-year period the best turf quality was achieved with Festuca rubra L. ssp. cultivars among the overseeded species, especially during fall. In many cases turf quality increased after manila grass green up since the combination of both cool season and warm season species gave a higher quality to the turfgrass, due to the finer leaf texture and higher shoot density of some cool season species. Moreover, recovery of manila grass ground cover was satisficing. In conclusion, a polystand of manila grass and Festuca rubra ssp. could be suitable for golf tees with low-input management.

Recent developments in metabolomics-based research in understanding transgenic grass metabolism.

Transgenic herbicide-resistant (HR) turfgrass together with its associated, broad spectrum herbicides promise cheap, selective and efficient weed control by excluding infested weeds resulting in turf lawn with high uniformity and aesthetic value. The concept of this "weeding program" initiated from modern biotechnology has been widely implemented in several principal crops including maize, soybean, canola and cotton as early as the 1990s. Transgenic HR turfgrass classified as a genetically modified organism (GMO) has undoubtedly caused public concern with respect to its biosafety and legalities similar to well-established HR crops. Nevertheless, applying metabolomics-based approaches which focuses on the identification of the global metabolic state of a biological system in response to either internal or external stimuli can also provide a comprehensive characterization of transgenic grass metabolism and its involvement in biosecurity and public perception. This review summaries the recent applications of metabolomics applied to HR crops to predict the molecular and physiological phenotypes of HR turfgrass species, glyphosate-resistant Kentucky bluegrass (Poa pratensis L.) and glufosinate-resistant creeping bentgrass (Agrotis stonifera L.). Additionally, this review also presents background knowledge with respect to the application of metabolomics, transformation of HR crops and its biosafety concerns, turfgrass botanical knowledge and its economic and aesthetic value. The purpose of this review is to demonstrate the molecular and physiological phenotypes of HR turfgrass based on several lines of evidence primarily derived from metabolomics data applied to HR crops to identify alterations on HR turfgrass metabolism as a result of genetic modification that confers resistant traits.

Evaluation of physiological and growing behavior of warm season turfgrass species against salinity stress

The demand for salinity tolerant turfgrasses is increasing due to augmented use of effluent or low quality water for turf irrigation. Fresh water, coupled with soil salinization in many areas has resulted in an increased need for screening of salt-tolerant turfgrasses. Physiological responses to salinity and relative salt tolerance of four C4 turf grasses Cynodon dactylon (Bermuda grass), Zoysia matrella (Manilla grass), Stenotaphrum secundatum (St. Augustine grass) and Paspalum notatum (Bahia grass) were investigated during the study at Division of Floriculture and Landscaping, IARI, New Delhi 2015-2017. Turfgrasses were planted in plastic pots filled with sand: cocopeat: vermiculite (2:1:1) and irrigated with different concentration of salinity levels (50, 100, 200, 300, 400 and 500 mm). Salinity tolerance was evaluated on the basis of leaf firing, shoots and root growth reduction, proline content, total chlorophyll content and relative water content was subjected to analysis of variance. Among the four turfgrass species S. secundatum found to be most salt tolerant turf grass followed by Z. matrella while P. notatum was least tolerant turfgrass against salt stress.

Grinding Methods Influence Nutrient Analysis of Bahiagrass and St. Augustinegrass

Particle reduction is a necessary step during turfgrass tissue analysis and may result in contamination of the sample with one or more elements. Metals such as W or Zr may reduce contamination because the metals are void of any plant essential elements. The objective of this study was to determine the nutrient content of turfgrass tissue submitted to eight grinding methods. Leaf tissue from bahiagrass (Paspalum notatum Flügge) and ‘Floratam’ St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] was collected and ground using one of the following eight methods: unground, Wiley mill, Cyclone mill, alumina beads, ceramic beads, stainless steel beads, tungsten carbide beads, and zirconium oxide beads. Tissue was analyzed for N, P, K, Ca, Mg, S, Al, Cu, Fe, Mn, Na, and Zn. Each method influenced turfgrass nutrient analysis by increasing, and in some cases decreasing, the concentration of one or more elements compared with unground tissue. Alumina and ceramic beads resulted in a decreased concentration of most elements, whereas the Wiley mill and tungsten beads resulted in an increase in N and Cu, and N and Mn, respectively. Grinding methods did not influence the concentration of P, K, S, Mn, or Na in bahiagrass but did alter their concentration in St. Augustinegrass. To minimize inaccurate analysis, the grinding method must account for additions or subtractions of elements resulting from the turfgrass species and the element analyzed.

Soil Carbon Accumulation and Nutrient Availability in Managed and Unmanaged Ecosystems of East Tennessee

Core Ideas Native woodlot and grassland systems have been converted to a managed turfgrass system with urbanization. Turfgrass systems increased carbon sequestration and nitrogen availability compared with row crop systems. Cool‐season (C3) turfgrasses improved soil physical and chemical properties more than warm‐season (C4) grasses. In the last two decades, urban and suburban lands grew by 34% in the United States, with 16 to 20 million ha maintained under turfgrass systems. Side‐by‐side comparison of turfgrass systems with other managed and unmanaged ecosystems have not been comprehensively conducted in the climate transition zone of the United States, despite the environmental significance of land use changes. Our objective was to determine the relative effects of C3 and C4 turfgrasses on soil organic carbon (SOC) accumulation and nutrient availability, in comparison with managed row crop and unmanaged woodlot and grassland systems. Soil samples from depths of 0 to 5, 5 to 15, and 15 to 30 cm were collected during March 2017 at the University of Tennessee's East Tennessee Research and Education Center from seven ecosystems: (i) corn (Zea mays L.)–soybean (Glycine max L.) rotation, (ii) continuous soybean, (iii) tall fescue (Festuca arundinacea L.), (iv) Kentucky bluegrass (Poa pratensis L.), (v) bermudagrass (Cynodon dactylon L.), (vi) unmanaged grassland, and (vii) unmanaged woodlot. All turfgrass species were established in 2012 and were managed like low‐input residential lawns. Within the 30‐cm soil profile, turfgrass systems contained 4.2 kg m−2 SOC at the time of sampling, which was 33% more than croplands and 34% less than unmanaged systems, and the C4 turfgrass system contained 2.3 kg m−2 SOC and 0.4 mg kg−1 inorganic N, which were 56 and 57% lower than C3 systems, respectively. Results from this study highlight that low‐input lawns with suitable grass species can offer higher SOC stock and nutrient availability than conventional cropland systems.