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Fall stockpiling of tall fescue (Lolium arundinaceum) in the southeastern United States is promoted as an ecologically favorable cattle management approach to avoid the financial and environmental burdens of winter hay feeding. We hypothesized that soil N mineralization should be an important factor controlling forage yield response to N fertilizer. We conducted 55 N fertilizer trials in combination with analyses of soil C and N fractions at multiple locations in Georgia, North Carolina, Virginia, and West Virginia during two seasons. Plant-available N, as a combination of residual inorganic N + mineralizable N at depth of 0 to 10 cm, was significantly negatively related with extent of forage dry matter response to N fertilizer input. Large variations in economically optimum N fertilizer requirement (EONR) occurred among fields, but when several fields were averaged along a gradient of soil biological activity, a strong negative yield response with increasing soil-test biological activity emerged. With moderate soil-test biological activity of 200 mg CO2-C kg-1 soil 3 d-1, EONR was 20 kg N Mg-1 forage dry matter (a value similar to current N fertilizer recommendations). However, with progressively greater soil-test biological activity up to 600 mg CO2-C kg-1 soil 3 d-1, EONR declined in a nonlinear manner to near zero. These results illustrate that N fertilizer recommendations for fall stockpiled tall fescue pastures should be a function of soil-test biological activity as an indicator of biologically active N. Greater economic and environmental sustainability would likely be attainable with a shift to recognizing soil biological activity in an ecologically oriented fertilization paradigm. [ABSTRACT FROM AUTHOR]

Well-managed irrigated pasture production can be optimized without nitrogen (N) fertilizer. The objective was to determine mixture and planting ratios of tall fescue (Schedonorus arundinacea Schreb.) (TF), meadow brome (Bromus riparius Rehm.) (MB), orchardgrass (Dactylis glomerata L.) (OG), timothy (Phleum pratense L.) (TIM), and perennial ryegrass (Lolium perenne L.) (PRG) with alfalfa (Medicago sativa L.) (ALF), birdsfoot trefoil (Lotus corniculatus L.) (BFTF), or cicer milkvetch (Astragalus cicer L.) (CMV) that maximize productivity. Planting ratios were 0:100 (grass:legume), 25:75, 50:50, 75:25, and three 100:0 grass monocultures fertilized at 0, 67, and 134 kg N ha-1. Seasonal production of TF-ALF was 12.69 Mg ha-1, equal to TF fertilized at 134 kg N ha-1. ALF mixtures with MB, OG, TIM, and PRG produced 12.57, 10.97, 11.77, and 10.74 Mg ha-1, respectively, and 8 to 40% more than grasses receiving 134 kg N ha-1. Production of BFTF mixtures with TF, MB, and OG were 11.69, 11.45, and 9.95 Mg ha-1, respectively, equal to their respective grass monoculture receiving 134 kg N ha-1. The BFTF-TIM and BFTF-PRG mixtures averaged 12% more forage than grass monocultures receiving 134 kg N ha-1. Production of CMV-grass was similar to that of grasses receiving 67 kg N ha-1. Seasonal forage distribution was more uniform in ALF- and BFTF-grass mixtures, averaging 30% more at the second and third harvests than fertilized grasses. The TF and MB legume mixtures averaged 7% more production in the 50:50 planting ratios than the other two grass-legume mixtures, while the 50:50 and 25:75 ratios of OG and TIM-legume mixtures averaged 12% more than the 75:25 and the 25:75 PRG-legume planting ratio averaged 9% more than the 50:50 and 75:25. Forage production of grass-legume mixtures can equal or exceed fertilized grass monocultures and with more uniform distribution over the growing season. [ABSTRACT FROM AUTHOR]

To evaluate the potentials of surfactants in reinforcing the phytoremediation of PAHs, the removal efficiencies of pyrene in soils with initial concentrations ranging 19.85 to 322.86 mg/kg were determined, and mechanisms of surfactant-enhanced phytoremediation (SEPR), as well as roles which surfactants played in the process of SEPR were discussed by a 70-day pot experiments in a greenhouse. Results showed that addition of surfactants (Tween 80) significantly reinforced dissipation of pyrene in spiked soils. During the entire experiment, 54.01~80.18% of pyrene had been removed in vegetated soils, which were 41.71~55.97% higher than those in corresponding non-vegetated soils. However, the removed pyrene in vegetated soils in the presence surfactants were up to 61.74~93.01%, which was 7.73~12.91% larger than those in the absence. Among removal pathways of pyrene, the plant-promoted biodegradation, either in the presence or absence of surfactants, was the most primary in the processes of SEPR. Our results indicated that surfactants have the potential to facilitate pollutant removal in spiked vegetated soils. [ABSTRACT FROM AUTHOR]

Tall fescue is an out-crossing allohexaploid grass species extensively used for forage and turf worldwide. Cultivars of outbreeding forage grasses such as tall fescue are usually synthetic populations derived from intercrossing several selected parents using the polycross method. In this study, the application of AFLP molecular markers to optimize genetic diversity in a polycross breeding program of tall fescue was evaluated. For both phenotypic characters and AFLP molecular markers, two polycrosses of six parental plants with contrasting levels of genetic diversity were composed. A fifth polycross population was composed using six genotypes with the highest general combining ability. The results of this study showed that marker assistant parental selection produced superior progenies, indicating that selection based on molecular marker diversity may be an appropriate means to improve first generation progenies of tall fescue. This may be mainly useful in large breeding programs because the identification of diversity based on phenotypic traits is time consuming and may be influenced by environmental effects. [ABSTRACT FROM AUTHOR]

The plant growth regulator trinexapac-ethyl (TE) is widely used to increase seed yield by reducing lodging in many grass species, including perennial ryegrass (Lolium perenneL.) and tall fescue (Festuca arundinaceaSchreb.). However, the seed yield responses of annual ryegrass (Lolium multiflorumLam.) to TE has not been widely investigated. In four field experiments, different rates of TE (between 0 and 800 g ha−1) were applied and the plant response measured. Seed yield was significantly (P < 0.05) increased above the control by all TE treatments with an average response of 51% and 65% for the 200 g and 400 g TE ha−1treatments, respectively. The seed yield response was associated with reduced lodging and shorter stems contributing to 1.1 more seeds per spikelet attaining saleable weight resulting in 72% more seeds m−2. The plant growth regulator TE can improve seed yield in well-managed stands of annual ryegrass. [ABSTRACT FROM PUBLISHER]

Grass biomass is a suitable feedstock for biogas production; however, this type of biomass in countries with a colder climate is too low. More research findings on the species of grasses and growing technologies will likely reveal the compatibility and interactions in an effort to ensure the required high-quality yield and the greatest potential for energy over the years to contribute to the development of biomass use. This study presents the results of experiments conducted on Endocalcari-Epihypogleyic Cambisol ( CMg-p-wcan ) to evaluate the biomass yield, quality and bioenergy potential of perennial grasses. Three perennial grasses—tall fescue ( Festuca arundinacea Schreb.), cocksfoot ( Dactylis glomerata L.) and reed canary grass ( Phalaris arundinacea L.)—were selected for biogas production. Different growing technologies were used to evaluate the influence of fertilisation (N 90 and N 180 ) and the cutting frequency (two and three cuts per growing season) on the biomass productivity and energy potential. The results of a two-year experiment suggest that the biomass yield and energy potential depend on grass species and growing technology. The highest biomass yield and energy potential was achieved for tall fescue harvested twice per season and for the first time at the flowering stage. [ABSTRACT FROM AUTHOR]

Tall fescue ( Festuca arundinacea Schreb.) is an important forage and turf grass species adapted to cold, arid and semiarid environments. Germination and seedling establishment of F. arundinacea cultivars is constrained by the low soil moisture found in these regions. Genome size was found to positively correlate with latitude of origin, suggesting that structural changes in DNA may play a role in environmental adaptation. We investigated the effects of low soil moisture on the germination and early establishment and their correlation with relative DNA content using 14 wild F. arundinacea populations collected from various regions in Iran and two commercial turf cultivars. The populations were evaluated under 100% (−0.03 matric potential [ MPa]), 80% (−0.2), 60% (−0.6) and 40% (−1.4) field capacity ( FC) conditions. Seed germination and root and leaf growth decreased under reduced soil water content. Cluster analysis revealed that the populations fell into four groups. Populations in cluster I showed the greatest tolerance to low soil moisture and cluster IV was the least tolerant. 'Isfahan' and 'Gonabad' populations had the best final germination and longer leaf and root length at 40% FC. Studies to identify indices that were involved in drought resistance revealed that final germination, leaf length and seedling vigor index were most important evaluating indicators for F. arundinacea populations. Flow cytometric relative DNA content of the wild populations was negatively correlated with germination, leaf length and seedling vigor index. The drought tolerance populations in cluster I could be potentially useful germplasm for a breeding program to develop superior cultivars for arid and semiarid regions. [ABSTRACT FROM AUTHOR]

There is increasing interest in tall fescue ( Festuca arundinacea Schreb.) in Western Europe and elsewhere, mainly because of its better drought resistance and yield potential compared with perennial ryegrass ( Lolium perenne L.). Important drawbacks of tall fescue, compared with perennial ryegrass, are its lower digestibility and voluntary intake. Mixtures of both species might combine the advantages of each, and species interactions may eventually lead to transgressive overyielding. We compared the agronomic performance of tall fescue, perennial ryegrass and tall fescue-perennial ryegrass mixtures, as pure-grass swards or in association with white clover ( Trifolium repens L.). Tall fescue-perennial ryegrass mixtures differed in the proportion and ploidy of the perennial ryegrass component. Yield, feed quality and botanical composition were measured in the 3 years after the sowing year. We found significant effects of ploidy of the ryegrass variety and of the proportion of ryegrass in the initial seed mixture on the botanical composition of the swards. Nevertheless, all swards were dominated by tall fescue at the end of the experiment. No overyielding of the mixtures compared with that of single-species swards was found, but feed quality was intermediate between that of the single-species swards. Mixed swards had better drought resistance than L. perenne and higher feeding quality than F. arundinacea swards. [ABSTRACT FROM AUTHOR]

Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] provides a major forage base for livestock production in the southeastern United States. Forage production using manure helps recycle nutrients with fewer environmental impacts. This study examined tall fescue forage production and soil chemical properties when using broiler litter (BL), dairy manure (DMN), commercial fertilizer (CF), and a control (UTC) treatment in no-till (NT) and conventional tillage (CT) systems. Forage nutritive values and majority of soil properties were not different in DMN, BL, and CF treatments. Herbage harvested was similar in BL and CF (9.3 and 8.1 Mg ha-1); DMN and UTC (6.6 and 5.6 Mg ha-1). Forage nutritive values in DMN and UTC were similar. Greater forage Cu and Zn contents were observed in BL and CF when compared to DMN and UTC. The soil pH of DMN treatment was 0.3 to 0.4 units higher than BL and CF. Soil organic matter (SOM) levels in all fertilizer treatments were similar (30.0-32.0 g kg-1). Broiler litter addition increased soil test P by 87%, NO3-N by 33%, and Cu by 30%, and Zn by 76%. The soil properties in DMN treatment did not change significantly. Tillage did not impact soil properties except for Fe; NDF (2012), Cu (2011), and Zn (2011). The results indicated that both broiler litter and dairy manure application can produce just as much herbage mass as commercial fertilizers with similar nutritive value. When manure is applied to meet crop N requirement, BL caused more intense soil nutrient loading than DMN. [ABSTRACT FROM AUTHOR]

Trinexapac-ethyl (TE) [4-(cyclopropyl-α-hydroxymethylene)-3,5-dioxo-cyclohexanecarboxylic acid ethylester] is a widely used plant growth regulator (PGR) for lodging control and seed yield enhancement in perennial ryegrass (Lolium perenne L.) and tall fescue [Schedonorus phoenix (Scop.) Holub], but little information is available on interaction of this PGR with spring-applied N. The objective of this study was to determine how spring-applied N and TE influenced seed production in perennial ryegrass (180 kg N ha-1) and tall fescue (135 kg N ha-1). Field trials were conducted over three harvest years in both crops. Interaction of spring-applied N and TE were evident for seed yield in all 3 yr in perennial ryegrass and in 2 yr in tall fescue. The combination of spring-applied N and TE produced the greatest yields among the treatments tested. Averaged over years, the combination of spring-applied N and TE PGR increased yield over the untreated control (no spring-applied N and no TE) by 859 kg ha-1 (126%) in perennial ryegrass and by 538 kg ha-1 (75%) in tall fescue. Responses of other seed production characteristics to spring-applied N and TE were independent of one another. Spring-applied N consistently increased aboveground dry weight and seed weight of both seed crops. Other characteristics were inconsistently affected or not affected by N or by TE. Spring-applied N x TE interaction effects in increasing yield were best explained by an increase in seed number per unit area. Perennial ryegrass and tall fescue seed yield is best enhanced by the lodging control agent TE with recommended rates of spring-applied N. [ABSTRACT FROM AUTHOR]

Development of a standard evaluation protocol has been a pressing problem for the selection of drought-resistant genotypes of tall fescue ( Festuca arundinacea). This study was conducted to evaluate the association of forage yield with specific phenological and morphological traits to find a proper model for indirect selection under irrigated (normal) and drought-stress conditions in tall fescue. A random sample of seventy-five genotypes were clonally propagated and evaluated in normal and drought-stress environments in the field during 2009 and 2010. Results showed that water stress had a negative effect on forage yield and most of the morphological traits measured and reduced genotypic variation for most of them. Forage yield had the highest genotypic variation, whereas days to pollination had the lowest variation. Low broad-sense heritability estimates were obtained for dry-matter yield, but heritability for the traits of number of stems per plant, plant height and crown diameter was moderately high. These traits were identified as the main components of forage yield. The importance of these components and their direct and indirect effects on forage yield was different in normal and drought-stress conditions. This suggests that indirect selection for developing high-yielding, drought-tolerant varieties should be performed under drought-stress conditions with a specific model. [ABSTRACT FROM AUTHOR]