Early spring and late autumn response to applied nitrogen in four grasses

1980 ◽  
Vol 94 (2) ◽  
pp. 443-453 ◽  
Author(s):  
D. Wilman ◽  
A. A. Mohamed
Keyword(s):  
Perennial Ryegrass ◽  
Leaf Blade ◽  
Unit Area ◽  
Total Yield ◽  
Early Spring ◽  
Late Winter ◽  
Number Of Leaves ◽  
Four Levels ◽  
Leaf Extension ◽  
Applied Nitrogen

SummaryThe regrowth of Aberystwyth S. 23 perennial ryegrass, S. 24 perennial ryegrass, S. 59 red fescue and S. 170 tall fescue was studied in field swards, comparing four levels of applied nitrogen, for 8 weeks following a clearing cut. The clearing cuts were in mid-October, mid-February and mid-March in each of 3 years, different plots being used on each occasion.The application of N increased the number of leaf primordia, the number of un-emerged leaves, the rate of leaf emergence and death, leaf blade length, width and weight, sheath length, number of leaves per unit area of ground and proportion of green tissue in total yield. The application of N had little effect on the number of leaves per tiller and tended to reduce weight per unit area of leaf blade. The increase in size, weight and number of leaf blades appeared to be major reasons for the positive effect of applied N on yield, previously reported; and the increase in sheath length contributed to the increase in proportion of yield above 4 cm. Rate of leaf extension was not closely related to yield and was more sensitive to temperature than was yield. Changes during regrowth in blade and sheath length helped to explain changes in weight per tiller, previously reported. The effects of improving weather conditions in late winter/early spring were similar to the effects of applied N: larger, heavier leaf blades, longer sheaths, a taller canopy, a lower proportion of dead material, younger leaves. The length of shoot apex per leaf primordium was relatively constant. Leaves continued to emerge, at a slow rate, in the period December–February. S. 170 had the biggest leaves, particularly in May, and the slowest rate of leaf turnover. Rate of leaf extension was increased by applied N more, on average, in the ryegrasses than in the fescues.

Early spring and late autumn response to applied nitrogen in four grasses

1980 ◽  
Vol 94 (2) ◽  
pp. 425-442 ◽  
Author(s):  
D. Wilman
Keyword(s):  
Perennial Ryegrass ◽  
Ground Level ◽  
Early Spring ◽  
Relative Growth ◽  
Red Fescue ◽  
Spring Period ◽  
Four Levels ◽  
Time Of Year ◽  
Positive Effect ◽  
Applied Nitrogen

SummaryThe regrowth of Aberystwyth S. 23 perennial ryegrass, S. 24 perennial ryegrass, S. 59 red fescue and S. 170 tall fescue was studied in field swards, comparing four levels of applied nitrogen, for 8 weeks following a clearing cut. The clearing cuts were in mid-October, mid-February and mid-March in each of 3 years, different plots being used on each occasion.Grass yield was more closely related to solar radiation receipt than to temperature. When radiation during the 3 or 4 weeks before a period of study was added to radiation during the 8-week period, to incorporate some allowance for temperature, the amount of additional yield per unit of additional radiation comparing the first spring period with the autumn period was about the same as that comparing the second with the first spring period. Where no N was applied, there was little or no increase in yield above ground level or above 4 cm from week 1 to about week 6 in the autumn and first spring period, whereas where N was applied yield increased steadily, though rather slowly, during those 5-week periods. Response to N, measured as kg dry matter above 4 cm/kg N applied, was about twice as great in the second as in the first spring period; on the other hand response to N measured as number of days saved in reaching a given yield was greater in the first than the second spring period. The positive effect of applied N on relative growth rate occurred mainly in the rather early stages of regrowth, which seems to be typical of any time of year.Applied N increased the N and nitrate-N content of herbage and reduced the watersoluble carbohydrate content. Applied N increased the number of tillers and the proportion of yield above 4 cm. Yield below 4 cm was not much affected by N or by stage of regrowth. The ‘earliness’ in spring of S. 24, S. 59 and S. 170 compared with S. 23 was associated with greater height and a higher proportion of yield above 4 cm and not with higher above-ground yield. The ryegrasses responded more to N than the fescues in respect of yield above 4 cm and number of tillers. In 2 years in which the number of tillers was relatively low at the beginning of the spring periods of study, the number increased during those periods and there was a large positive effect of applied N, whereas, in a year in which the number was high initially, there was no increase during the periods of study and little response to N.

Herbage production and the accumulation of soil nitrogen under irrigated pastures on the Riverine Plain

1974 ◽  
Vol 14 (66) ◽  
pp. 49 ◽  
Author(s):  
CR Kleinig ◽  
JC Noble ◽  
AJ Rixon
Keyword(s):  
Perennial Ryegrass ◽  
Soil Nitrogen ◽  
White Clover ◽  
Accumulation Rate ◽  
Total Yield ◽  
Subterranean Clover ◽  
Nitrogen Accumulation ◽  
Total Soil ◽  
Total Soil Nitrogen ◽  
Applied Nitrogen

Herbage yield, herbage nitrogen, and soil nitrogen accumulation were followed over a five-year period (1958-63) under irrigated annual and perennial pastures established initially with different clovergrass proportions. Species sown in the annual pasture treatments were subterranean clover (Trifolium subterraneum cv. Tallarook) and annual ryegrass (Lolium rigidum cv. Wimmera). Those used in the perennial mixtures were white clover (T. repens cv. Irrigation) and perennial ryegrass (L. perenne cv. Victorian). In the treatments sown to annual or perennial ryegrass only, nitrogenous fertilizer as urea was applied annually at four rates. Total soil nitrogen (mat + 0-91 cm of soil) after five years did not differ significantly for annual pasture and bare ground. In contrast, total soil nitrogen under all perennial pasture treatments, particularly those with a white clover component, was significantly greater than for bare soil (5365 cf. 4181 kg ha-1). Where white clover was sown, nitrogen accumulated at the rate of 258 kg ha-1 per annum compared with 101 kg ha-1 per annum under subterranean clover, the latter barely matching the accumulation rate under perennial ryegrass sown alone without applied nitrogen (105 kg N ha-1 p.a.). Nitrogen accumulation (soil plus mat) was related to both legume and non-legume nitrogen. Perennial pasture, particularly if white clover was present, generally outyielded annual pasture. The total yield of white clover over five years was 29,970 kg ha-1 compared with 11,614 kg ha-1 for subterranean clover. Annual and perennial ryegrasses showed similar yield responses to applied nitrogen. Irrespective of the rate of urea application, nitrogen recovery was low (21-23 per cent).

Effects of harvesting programme and sowing date on leaf growth in forage barley in Cyprus

1988 ◽  
Vol 110 (2) ◽  
pp. 353-366
Author(s):  
D. Wilman ◽  
D. N. Droushiotis
Keyword(s):  
Leaf Blade ◽  
Field Experiments ◽  
Leaf Growth ◽  
Main Stem ◽  
Available Nitrogen ◽  
Leaf Production ◽  
Primary Tiller ◽  
Sowing Dates ◽  
Number Of Leaves ◽  
Applied Nitrogen

SummaryAll combinations of four harvesting treatments and two sowing dates were compared in each of 2 years in field experiments near Nicosia. In one of the years, two levels of applied nitrogen were compared. The harvesting treatments were: (1) a milk-stage cut, (2) a boot-stage cut and a regrowth cut, (3) a grazing-stage cut and a regrowth cut, and (4) three grazing-stage cuts and a regrowth cut. The sowing dates were (1) normal (12 November) and (2) early (15 October), with sufficient irrigation to ensure establishment.Applied nitrogen had virtually no effect on leaf growth, evidently because of high reserves of available nitrogen in the soil. Early sowing increased the rates of leaf emergence, extension and expansion up to the time of the first ‘grazing’ cut (when the first node was showing) and reduced the number of leaves which died in that period. Where growth was uninterrupted to the milk stage, early sowing did not affect the number of leaves produced by a main stem or primary tiller, but increased the longevity of the later leaves. Where there were three ‘grazing’ cuts, early sowing allowed time for the production of more and larger leaf blades, with longer sheaths, between the third 'grazing’ cut and the final harvest.The ‘grazing’ cuts considerably reduced the rates of extension and expansion and the final size of the leaves which emerged soon after a cut. There was good recovery subsequently, however, in rates of extension and expansion and final leaf size, particularly with October sowing.During almost all the period of leaf production on a main stem or primary tiller, several leaves (up to six) were expanding at the same time. The stage, during the period between emergence and death, at which a leaf blade reached its full length was typically half-way between emergence and death. Where growth was uninterrupted, area per leaf blade was positively correlated with both the number of days between the emergence of successive leaves and the number of days between emergence and death.

Effects of plant density and fertilization on the yield and quality of flue-cured tobacco in the Kenana area of the Sudan

1975 ◽  
Vol 84 (1) ◽  
pp. 75-80 ◽  
Author(s):  
S. M. Farah
Keyword(s):  
Plant Density ◽  
Unit Area ◽  
Yield And Quality ◽  
Fertilizer Experiment ◽  
Number Of Leaves ◽  
Four Levels ◽  
Higher Doses

SUMMARYIn one experiment, variety Kutsaga 51 was grown at inter- and intra-row spacings of 60, 80 and 100 cm. Both yield and quality of leaf were improved as plant density per unit area increased. The greatest yield and highest quality were obtained from the 60 x 60 and 80 x 60 cm spacings while the lowest yield and quality were obtained from the 100 x 100 and 100 x 80 cm spacings.In a second experiment the same variety was subjected to three levels of N and four levels of K. Higher doses of N or K were not necessarily effective in increasing the yield or improving the quality of leaf; on the contrary rates higher than 42/ha reduced both yield and quality of the leaf. Progressively higher doses of K did not offset the ill effects of excessive N.Yield of leaf was primarily a function of leaves per unit area in the plant density experiment and number of leaves per plant in the fertilizer experiment.

The long-term impact of nitrogen fertiliser on perennial ryegrass tiller and white clover growing point densities in grazed dairy pastures in south-western Victoria

2002 ◽  
Vol 53 (11) ◽  
pp. 1203 ◽  
Author(s):  
F. R. McKenzie ◽  
J. L. Jacobs ◽  
G. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Block Design ◽  
Early Spring ◽  
Late Winter ◽  
Climatic Effects ◽  
Nitrogen Fertiliser ◽  
Point Density ◽  
Long Term Impact ◽  
The Impact

A 3-year grazing experiment determined the impact of multiple applications of different rates of nitrogen (N) fertiliser, applied over autumn and winter in 1997, 1998, and 1999, on perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) tiller and growing point densities (stolon apices with at least 2 nodes). Annual pasture dry matter (DM) yields were also monitored. Four treatments were replicated 3 times in a randomised block design and included: 0 N (A); 3 applications of 25 kg N/ha (B); 3 applications of 50 kg N/ha (C); and 3 applications of 75 kg N/ha (D). Urea (46% N) was the N source. Grazing of treatment plots occurred at a pre-grazing herbage mass of 2200–2500 kg DM/ha.Over 3 years, N applications consistently increased annual pasture DM yields by 0.9–3.3 t/ha when a total of 75–225 kg N/ha was applied annually.Generally, treatments B, C, and D resulted in higher perennial ryegrass tiller densities than treatment A. An exception occurred from July 1998 in Year 2 to July 1999 in Year 3, when all perennial ryegrass densities were similar. Nitrogen fertiliser generally produced no consistent effect on white clover growing point density, with the exception of July–December in Year 2 when treatments B, C, and D resulted in lower growing point densities than treatment A. Clover growing point density decreased over the trial period irrespective of treatment. There were no N fertiliser effects on 'other' grasses and broadleaved weeds. 'Other' grasses (mainly winter grass, Poa annua) did, however, peak in density (up to 2500 tillers/m2) from July to September each year.Seasonally, the peak perennial ryegrass tiller density was similar each year and occurred during late winter–early spring (5450 tillers/m2 in July 1997; 6200 tillers/m2 in August 1998; 5400 tillers/m2 in July 1999). This was followed by a trough over midsummer (800 tillers/m2 in January 1998; 725 tillers/m2 in January 1999). White clover growing point density declined over 3 years. During this decline there were peaks in June 1997 (2650 growing points/m2), November 1997 (1600 growing points/m2), June 1998 (1250 growing points/m2), April 1999 (1050 growing points/m2), and November 1999 (850 growing points/m2). Troughs occurred in January 1998 (530 growing points/m2) and February 1999 (380 growing points/m2).It is concluded that although increasing applications of N increased annual pasture DM yields and generally increased perennial ryegrass tiller densities, with little effect on clover growing point densities, there is little to suggest that N fertiliser alone would enhance the persistence of these pasture species. Persistence is likely to be influenced by a combination of factors including grazing management and climatic effects, rather than N fertiliser alone.

scholarly journals Phenotypic Response of Two Garlic Varieties to Different Nitrogen Fertilization Grown under Irrigation in Sudan Savannah Ecological Zone of Nigeria

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Magaji G. Usman ◽  
A. S. Fagam ◽  
Rilwanu U. Dayi ◽  
Zaharaddeen Isah
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Block Design ◽  
Total Yield ◽  
Maximum Growth ◽  
Growth And Yield ◽  
Nitrogenous Fertilizer ◽  
Randomized Complete Block Design ◽  
Number Of Leaves ◽  
Four Levels

A study was conducted under irrigation during dry season at the Katsina State Irrigation Site, Ajiwa. The aim of the experiment was to enhance the productivity of garlic through the choice of appropriate levels of nitrogenous fertilizer and suitable cultivar which maximizes yield. The experiment consisted of two varieties (ex-kofa and ex-sokoto) and four levels of nitrogen (0, 50, 100, and 150 kgN/ha). They were arranged in a randomized complete block design in three replications. The variety ex-sokoto was found superior to ex-kofa with respect to plant height, number of leaves, leaf area, and days to maturity, number of bulbs, bulb diameter, bulb weight, and number of cloves per bulb, cloves weight per bulb, and fresh and cured bulb yield. Application of 50 kgN/ha significantly increased plant height (cm), number of leaves per plant, leaf area, number of bulbs, and the total yield of the garlic. Significant effects of interaction between variety and nitrogen on leaf area and number of cloves per bulb of the garlic were observed. The combination of ex-sokoto variety and 50 kgN/ha was found to increase garlic yield. Maximum growth and yield could be realized using a combination of ex-sokoto variety and 50 kgN/ha at Ajiwa.

scholarly journals Soil Temperature Mediated Seedling Emergence and Field Establishment in Bentgrass Species and Cultivars during Spring in the Northeastern United States

2020 ◽  
pp. 1-11
Author(s):  
J. Scott Ebdon ◽  
Michelle DaCosta
Keyword(s):  
Soil Temperature ◽  
Perennial Ryegrass ◽  
Unit Area ◽  
Seedling Emergence ◽  
Creeping Bentgrass ◽  
Experimental Period ◽  
Early Spring ◽  
Golf Greens ◽  
Soil Temperatures ◽  
Mature Stands

Reestablishment of damaged golf greens and fairways planted to creeping bentgrass (Agrostis stolonifera), colonial bentgrass (A. capillaris), and velvet bentgrass (A. canina) is a common practice following winter injuries. Identifying bentgrass species (Agrostis sp.) and cultivars with the potential to establish under low soil temperatures would be beneficial to achieving more mature stands earlier in the spring. Twelve bentgrass cultivars, including seven cultivars of creeping bentgrass (007, 13-M, Declaration, L-93, Memorial, Penncross, and T-1), two colonial bentgrass cultivars (Capri and Tiger II), and three velvet bentgrass cultivars (Greenwich, SR-7200, and Villa), along with ‘Barbeta’ perennial ryegrass (Lolium perenne) were evaluated for grass cover in the field during early spring. Bentgrass species and cultivars were seeded in the field at the same seed count per unit area. Soil temperatures were monitored in unseeded check plots from initial planting date on 8 Apr. to termination on 29 May 2013. Soil temperatures increased linearly during the 52-day experimental period from 4.7 to 23.5 °C. All species and cultivars emerged at ≈10 °C soil temperature. Bentgrass species and cultivars varied only 2 to 3 days in their initial seedling emergence, while days varied among bentgrasses from 5.5 days (to 10% cover) to 8.6 days (to 90% cover). All velvet bentgrass cultivars required higher soil temperatures (13.6 °C) and more time (26 days) following initial seedling emergence to establish to 90% cover in the early spring. Creeping bentgrass cultivars 007, 13-M, and Memorial, along with colonial bentgrass cultivars Capri and Tiger II, were statistically equal to ‘Barbeta’ perennial ryegrass in their capacity after seedling emergence to achieve faster cover at lower soil temperatures. Heavier (larger) bentgrass seed was associated with faster cover during the early stages of establishment, but seed size was uncorrelated with establishment during later stages from 50% to 90% cover.

Seasonal activity and estivation of lumbricid earthworms in the midlands of Tasmania

Soil Research ◽  
1994 ◽  
Vol 32 (6) ◽  
pp. 1355 ◽  
Author(s):  
RB Garnsey
Keyword(s):  
Soil Moisture ◽  
Adult Development ◽  
Survival Rates ◽  
Soil Surface ◽  
Early Spring ◽  
Lumbricus Rubellus ◽  
Late Winter ◽  
Cocoon Production ◽  
Density And Biomass ◽  
Earthworm Activity

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (<600 mm rainfall p.a.), and examines, for the first time in Australia, the behaviour and survival rates of aestivating earthworms. Earthworms were sampled from 14 permanent pastures in the Midlands from May 1992 to February 1994. Earthworm activity was significantly correlated with soil moisture; maximum earthworm activity in the surface soil was evident during the wetter months of winter and early spring, followed by aestivation in the surface and subsoils during the drier summer months. The two most abundant earthworm species found in the Midlands were Aporrectodea caliginosa (maximum of 174.8 m-2 or 55.06 g m-2) and A. trapezoides (86 m-2 or 52.03 g m-2), with low numbers of Octolasion cyaneum, Lumbricus rubellus and A. rosea. The phenology of A. caliginosa relating to rainfall contrasted with that of A. trapezoides in this study. A caliginosa was particularly dependent upon rainfall in the Midlands: population density, cocoon production and adult development of A. caliginosa were reduced as rainfall reduced from 600 to 425 mm p.a. In contrast, the density and biomass of A. trapezoides were unaffected by rainfall over the same range: cocoon production and adult development continued regardless of rainfall. The depth of earthworm aestivation during the summers of 1992-94 was similar in each year. Most individuals were in aestivation at a depth of 150-200 mm, regardless of species, soil moisture or texture. Smaller aestivating individuals were located nearer the soil surface, as was shown by an increase in mean mass of aestivating individuals with depth. There was a high mortality associated with summer aestivation of up to 60% for juvenile, and 63% for adult earthworms in 1993 in the Midlands. Cocoons did not survive during the summers of 1992 or 1994, but were recovered in 1993, possibly due to the influence of rainfall during late winter and early spring.

TEMPERATURE RESISTANCE OF GOLDFISH MAINTAINED UNDER CONTROLLED PHOTOPERIODS

1959 ◽  
Vol 37 (4) ◽  
pp. 419-428 ◽  
Author(s):  
William S. Hoar ◽  
G. Beth Robertson
Keyword(s):  
Temperature Change ◽  
Seasonal Variations ◽  
Rapid Growth ◽  
Endocrine System ◽  
Early Spring ◽  
Late Winter ◽  
Thyroid Activity ◽  
Temperature Resistance ◽  
Sudden Temperature Change

Goldfish maintained under controlled photoperiods for 6 weeks or longer were relatively more resistant to a sudden elevation in temperature when the daily photoperiods had been long (16 hours) and relatively more resistant to sudden chilling when they had been short (8 hours). The magnitude of the effect varied with the season. Thyroid activity was slightly greater in fish maintained under the shorter photoperiods. The longer photoperiods stimulated more rapid growth of ovaries during late winter and early spring. The endocrine system is considered a link in the chain of events regulating seasonal variations in resistance to sudden temperature change.

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