scholarly journals Shear characteristics on soil specimen including roots of Festuca arundinacea Schreb. and Festuca longifolia Thuill. with taking notice of the difference of slope directions

2017 ◽  
Vol 43 (1) ◽  
pp. 15-20
Author(s):  
Toshimi MUNEOKA ◽  
Daiki SUGAWARA ◽  
Yuri YAMAZAKI ◽  
Masato KIMURA ◽  
Osamu TSUJI
Keyword(s):  
Festuca Arundinacea ◽  
Soil Specimen ◽  
Shear Characteristics ◽  
The Difference

The effects of ozone and nitrogen fertilizer on tall fescue, ladino clover, and a fescue–clover mixture. II. Nitrogen content and nitrogen fixation

1983 ◽  
Vol 61 (8) ◽  
pp. 2159-2168 ◽  
Author(s):  
Ruben A. Montes ◽  
Udo Blum ◽  
Allen S. Heagle ◽  
Richard J. Volk
Keyword(s):  
Nitrogen Fixation ◽  
Tall Fescue ◽  
Difference Method ◽  
Festuca Arundinacea ◽  
Ambient Air ◽  
N Fertilization ◽  
Dilution Method ◽  
N Fixation ◽  
The Difference ◽  
N Dilution Method

The effects of chronic doses of ozone (O3) and rates of nitrogen (N) fertilizer on N content of ladino clover (Trifolium repens L. cv. Tillman) and tall fescue (Festuca arundinacea Schreb. cv. Kentucky 31), and on N fixation by the clover were studied during the 1979 growing season. Plants of the two species were grown (i) in pots separately, (ii) together in open-top field chambers, and (iii) in ambient air plots. Mean 7 h/day (0930–1630 h eastern daylight time) O3 concentrations for the study period were 0.03 ppm in charcoal-filtered air chambers, 0.05 ppm in nonfiltered air chambers, 0.08 ppm in nonfiltered air chambers with O3 added for 7 h/day, and 0.05 ppm in ambient air. Shoot N concentrations (milligrams per gram dry weight) for clover and fescue were not modified by O3 exposures nor by N fertilization. Higher ozone levels led to reduced system N fixation (milligrams N per pot) by clover grown separately or together with fescue. Nitrogen fixation by ladino clover grown with tall fescue was 1.4 times greater than that by the clover grown alone. Nitrogen fixation by clover as estimated by the difference method was approximately 45% lower than N fixation as estimated by the 15N dilution method. Nitrogen fixation estimated by the difference method declined significantly with increasing N fertilization. This was not the case for N fixation estimated by the 15N dilution method.

scholarly journals Differential Large Crabgrass Control with Herbicides in Tall Fescue and Common Bermudagrass

HortScience ◽  
1993 ◽  
Vol 28 (10) ◽  
pp. 1015-1016 ◽  
Author(s):  
B.J. Johnson
Keyword(s):  
Field Experiment ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Cynodon Dactylon ◽  
Late Summer ◽  
Application Rates ◽  
The Difference ◽  
Common Bermudagrass ◽  
Large Crabgrass

Pendimethalin and oxadiazon are used commonly to control crabgrasses (Digitaria spp.) in tall fescue (Festuca arundinacea Schreb.) and common bermudagrass [Cynodon dactylon (L.) Pers.]. A field experiment was conducted for 2 years to determine if reduced pendimethalin and oxadiazon application rates would control large crabgrass [D. sanguinalis (L.) Sco.] effectively in tall fescue and common bermudagrass. Oxadiazon applied at 1.1 kg a.i./ha in each of two applications at a 60-day interval (less than recommended rate) effectively controlled large crabgrass (≥93%), regardless of turfgrass species. Pendimethalin applied at 1.1 kg a.i./ha in each of two applications controlled large crabgrass in common bermudagrass effectively (≥90%) but not large crabgrass in tall fescue (47%). The difference in pendimethalin performance between the two species was attributed to the ability of common bermudagrass to compete more successfully than tall fescue with large crabgrass during late summer. Chemical names used: 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethy1)-l,3,4-oxadiazol-2-(3 H)-one (oxadiazon); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin).

Competitive interaction of grasses with contrasting temperature responses and water stress tolerances

1974 ◽  
Vol 25 (2) ◽  
pp. 227 ◽  
Author(s):  
W Harris ◽  
A Lazenby
Keyword(s):  
Water Stress ◽  
Festuca Arundinacea ◽  
Diallel Analysis ◽  
Short Rotation ◽  
Digestible Organic Matter ◽  
Different Seasons ◽  
Second Year ◽  
The Difference ◽  
Water Treatments ◽  
Temperature Responses

Lolium perenne (cv. Kangaroo Valley ryegrass), L. perenne x multiforum (cv. 'Grasslands Manawa' short rotation ryegrass), Phalaris tuberosa (cv. Australian Commercial),Festuca arundinacea (cv. Demeter) and Paspalum dilatatum were grown for 2 years in monoculture and two-species mixtures, under dryland and irrigated treatments at Armidale, N.S.W. Competition effects were described, with the use of diallel analysis. Early aggressivities were in the order L. perenne × multiflorum > L. perenne > F. arundinacea = P. tuberosa > P. dilatatum in both water treatments; subsequently, the aggressiveness of F. arundinacea, P. tuberosa and P. dilatatum increased relative to the ryegrasses (especially L. perenne), P. tuberosa (more so in the dryland treatment) and P. dilatatum (particularly in summer and autumn). Specifically high aggressivities of P. tuberosa towards P. dilatatum and P. dilatatum towards L. perenne were shown. Under dryland conditions, the P. tuberosa monoculture produced the highest yield in both years, differing markedly from L. perenne × multiforum in response to limited water availability. Under irrigation overall gains of yield were obtained by mixing grasses in the second year, the gains being significant for ryegrass-P. dilatatum mixtures. This response is related to the different growth potentials of the species in different seasons with the proviso that conditions such as water stress or excess suppression do not limit the expression of these potentials. Although P. dilatatum was of lower digestibility than the ryegrass, the difference was not sufficiently large to cancel the gain from mixing when expressed as digestible organic matter (DOM). An unsatisfactory feature of these mixtures was the depressive effect on winter yield of dormant P. dilatatum. By comparison, winter yield stimulation by mixing P. tuberosa and L. perenne, occurring when digestibilities were high, contributed to a significant gain of DOM yield by this mixture. Marked dominance of L. perenne × multiforum under dryland conditions, although appearing to assist the survival of this species in mixture, was detrimental in that by suppressing P. tuberosa, F. arundinacea and P. dilatatum, it restricted the potential of these species to produce in dryland conditions. There was evidence that F. arundinacea depressed yield in mixture, especially when associated with L. perenne.

scholarly journals Pasture management and pasture species for improved dry matter production in south Taranaki

1990 ◽  
pp. 109-112
Author(s):  
T.G. Judd ◽  
N.A. Thomson ◽  
D.A. Mccallum
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Dry Matter ◽  
Seasonal Distribution ◽  
Annual Production ◽  
Pasture Management ◽  
Pasture Production ◽  
The Difference ◽  
Alternative Species ◽  
Dactylis Glomerata L

Dry matter (DM) production and seasonal distribution of old ryegrass/white clover pasture defoliated at 14- and 28day intervals, and new sowings of 'Grasslands Maru' phalaris (Phaluris aquatica L.), 'Grasslands Roa' tall fescue (Festuca arundinacea Schreb.), and 'Grasslands Kara' cocksfoot (Dactylis glomerata L.) at 28day defoliation intervals were evaluated in an environment prone to grass grub damage and dry summer/autumn periods. Under a 28&y defoliation interval old ryegrass produced 2O%more DM that the 14-day defoliation interval, the difference occuring mainly in spring. Annual production, in the initial 4 years, of phalaris and tall fescue was respectively 17 % and 20 % more than that of old ryegrass. Phalaris was superior to old ryegrass in all seasons. Cocksfoot annual production was similar to that of old ryegrass, producing more in summer (9%) and autumn (19%) but 15% less in spring. Results from year 5 and 6 suggest that phalaris may not be as persistent as tall fescue. A 28-day rotation in spring is recommended to maximise production of old ryegrasslclover pasture. Phalaris and tall fescue are recommended as alternative species to old ryegrass in a grass grub prone and/or summer dry environment. Cocksfoot is not recommended. Keywords pasture production, seasonal distribution, cow requirements, old ryegrass, phalaris, tall fescue, cocksfoot

Morphology of tall fescue (Festuca arundinacea) and perennial ryegrass (Lolium perenne) plants in pastures under sheep and cattle grazing

1997 ◽  
Vol 129 (1) ◽  
pp. 19-31 ◽  
Author(s):  
D. E. HUME ◽  
J. L. BROCK
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Seasonal Fluctuation ◽  
Dry Weight ◽  
Cattle Grazing ◽  
Major Effect ◽  
Grazing Management ◽  
Plant Structure ◽  
The Difference

The effects of contrasting management systems either of infrequent rotational grazing by town milk supply dairy cattle, or of frequent defoliation by continuously grazing sheep and beef cattle, on the morphology of independent plants and populations of ‘Grasslands Roa’ tall fescue in mixed pastures, were measured over 1 year (1992/93) in New Zealand. Volunteer perennial ryegrass plants were also measured for comparison.While both species exhibited a similar pattern of clonal growth, tall fescue developed more plants of higher branching complexity than perennial ryegrass, chiefly through maintaining more connective stems, as herbage production was confined to the three youngest branching orders in both species. Greater resistance to microbial degradation of old stems through poorer quality organic matter (wide C[ratio ]N ratio) compared to perennial ryegrass may be responsible for the greater complexity of fescue plants. In addition, tillering rates in tall fescue were three times lower which was offset by greater longevity and size of leaves and tillers, compared to perennial ryegrass. As a result, seasonal fluctuation in the distribution of plants among the various branching orders in tall fescue was small, producing a more stable population relative to the distinct seasonal changes in the population of perennial ryegrass plants. Grazing management had no effect on the seasonal population structure in either species.Differences in plant structure due to grazing management were small, with only slightly more tillers on sheep-grazed than on cattle-grazed tall fescue plants. The major effect of grazing management was on dry weight or size of plant components. Cattle-grazed tall fescue plants were 120% heavier, with greater numbers and lengths of stolons and flower heads than those under sheep grazing. For the volunteer perennial ryegrass, the difference was only 65%, possibly due to competition from the more vigorous tall fescue under rotational cattle grazing.Both species produced stolons throughout the year, although these were primarily associated with reproductive growth in spring. In tall fescue, an additional distinction was made between stolon and rhizome, the latter occurring mainly in the summer–autumn. Their possible functions in plant growth are discussed.

scholarly journals Shear characteristics on soil specimen including roots of 10 types of herbaceous plants.

2018 ◽  
Vol 44 (1) ◽  
pp. 9-14
Author(s):  
MUNEOKA Toshimi ◽  
SHIMODA Seiya ◽  
YAMAZAKI Yuri ◽  
KIMURA Masato ◽  
TSUJI Osamu
Keyword(s):  
Herbaceous Plants ◽  
Soil Specimen ◽  
Shear Characteristics

scholarly journals Comparison of Soil–Water Characteristic Curves in One-Dimensional and Isotropic Stress Conditions

Soil Systems ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 43 ◽  
Author(s):  
Paul Habasimbi ◽  
Tomoyoshi Nishimura
Keyword(s):  
Soil Water ◽  
Characteristic Curve ◽  
Matric Suction ◽  
Stress Conditions ◽  
Data Sets ◽  
Soil Specimen ◽  
Soil Behavior ◽  
Confining Stress ◽  
One Dimensional ◽  
The Difference

Understanding unsaturated soil behavior is key to the design of foundations and embankment structures. Geotechnical engineers have applied net normal stress and matric suction to these engineering problems. Water retention activity in soils is used to predict seepage problems and stability of slope failures. Soil–Water Characteristic Curve (SWCC) tests contribute largely to matric suction interpretation. Determination of SWCCs in the laboratory is usually done using a pressure plate apparatus where vertical or confining stress cannot be applied. Mathematical models of SWCC though commonly accepted in geotechnical engineering practices, do not take into consideration stress conditions such as the difference between a one-dimensional condition and isotropic confining conditions. This study conducted SWCC tests of a silt soil under one-dimensional and isotropic confining stress conditions and focused on the differences between these types of SWCC data sets. Vertical and isotropic confining stresses ranging from 100 to 600 kPa were applied under both stress conditions. SWCCs appears to be affected by the influence of different stress conditions. Lateral pressure and confinement on an isotropic compression condition caused the soil specimen to become dense in void structure and consequently, soil moisture flow movement decreased. This probably induced high retention activities in the silt soil specimen. The study further suggests that the current SWCC models require further development to take into consideration the effect of different stress conditions.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

Influence of Cell Wall Composition on the Fossilisation of Bacteria and the Implications for the Search for Early Life Forms

1997 ◽  
Vol 161 ◽  
pp. 491-504 ◽  
Author(s):  
Frances Westall
Keyword(s):  
Cell Wall ◽  
Life Forms ◽  
Cation Binding ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Hydrothermal Sediments ◽  
Identification Of Bacteria ◽  
The Difference

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

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