The effect of cutting frequency and root segregation on the yield from perennial ryegrass-white clover associations

1967 ◽  
Vol 69 (3) ◽  
pp. 391-397 ◽  
Author(s):  
B. F. Bland

1. Dry-matter and nitrogen yields were recorded from perennial ryegrass-white clover associations which were defoliated 2, 4 or 6 times a year during the period 1963 to 1965.2. The average yearly output of dry matter was approximately 4000, 7000 and 6000 lb/acre for 1963, 1964 and 1965 respectively. Nitrogen harvested amounted to 132, 184 and 179 lb N/acre.3. The mean annual dry-matter yields from 2, 4 and 6 defoliations were 5300, 6100 and 6000 lb/acre and the corresponding figures for nitrogen yields were 112, 166 and 217 lb N/acre.4. Both segregation of the species below ground and increasing the defoliation frequency were responsible for higher contributions towards drymatter and nitrogen yield from the clover component.5. A comparison of the nitrogen yields between the plots with species segregated rather than integrated below ground suggests that the effects of underground nitrogen transference from 30–31 lb N/acre could first be demonstrated in the spring of the third year.

1973 ◽  
Vol 80 (2) ◽  
pp. 323-327 ◽  
Author(s):  
J. E. Newton ◽  
J. E. Betts

SummaryDuring 3 years, three groups of 20 Scottish half-bred ewes were grazed on perennial ryegrass, white clover or red clover. During this period the two legumes were oestrogenic, in terms of teat-length extension of wethers, but the perennial ryegrass was not. The white clover was only markedly oestrogenic when there was a high proportion of diseased leaves. The mean litter size and lambing percentage of the ewes grazed on red clover was significantly reduced. White clover, although it was oestrogenic, had no effect on mean litter size or lambing percentage. The mean litter size of the ewes on the perennial ryegrass was 2·35, 2·30 and 2·24, on the white clover was 2·20, 2·33 and 2·23 and on the red clover was 1middot;60, 1·67 and 1·78 for the three lambings. Lambing percentage of the ewes on the perennial ryegrass was 175, 225 and 218, on the white clover was 210, 222 and 189, and on the red clover was 160, 128 and 118 for the three lambings. The lambing date of the ewes grazing on the red clover was significantly later at the third lambing.


1997 ◽  
Vol 48 (6) ◽  
pp. 811 ◽  
Author(s):  
A. R. Lawson ◽  
P. W. G. Sale ◽  
K. B. Kelly

A field experiment was carried out to investigate whether changes in winter and post-winter defoliation frequency would increase the white clover content of an irrigated perennial ryegrass–white clover pasture in northern Victoria. Pastures defoliated every 4 weeks during winter had higher white clover growing point (stolon apices with at least 2 nodes) density at the end of winter than pastures defoliated every 8 weeks or those receiving a single defoliation after 16 weeks, but these differences did not affect the clover content in the spring. Reasons for this are suggested. Pastures defoliated at 8-week intervals in winter were the most productive over winter{early spring. Less frequent defoliation (4 v. 2 weeks) during the post-winter, September–May period reduced white clover growing point and perennial ryegrass tiller densities. However, the white clover growth rate during this period was increased by less frequent defoliation, whereas the ryegrass growth rate was reduced, resulting in an increase of 10% in the white clover content, and a 1·9 t dry matter (DM)/ha increase in total DM produced. This higher clover content and pasture yield during spring–autumn with less frequent defoliation has important implications for the management of irrigated perennial pastures for the dairy industry in northern Victoria.


1967 ◽  
Vol 7 (25) ◽  
pp. 157 ◽  
Author(s):  
RJ Jones

Uninterrupted growth of Siratro (Phaseolus atropurpureus) in a Siratro-grass pasture was slow in spring, increased rapidly in mid-December, and attained a maximum growth rate of 79 lb dry matter an acre a day in February-March. The slow spring growth appeared to be associated with low temperatures. Yield and percentage of Siratro increased for at least 191 days after commencement of growth in spring. Yields of Siratro increased linearly from 1400 lb to 6500 lb dry matter an acre as the cutting interval increased from 4 to 16 weeks. Yields of other species declined as the cutting interval increased. With a 4-weekly cutting regime, the stand of Siratro was greatly reduced after one season. Lucerne subjected to the same treatment gave higher yields and the stand remained good. Urea reduced the mean yield of Siratro by 16 per cent and 33 per cent at the N,, and N,,, levels respectively, but increased total dry matter yields. The response of Siratro to cutting frequency was quite different from that reported for white clover. This difference may be of fundamental importance in the management of sub-tropical grass-legume pastures.


1997 ◽  
Vol 45 (2) ◽  
pp. 263-275
Author(s):  
R.L.M. Schils

In a field trial in 1989-93 on clay soil at Lelystad, Netherlands, a mixed sward of Lolium perenne cv. Profit and Magella and Trifolium repens cv. Retor was given annual applications of 0, 25, 50, 75 or 100 kg N ha-1 and was cut 4-5 or 6-7 times a year. In a trial in 1992-94 on sandy soil in Overijssel, a sward of L. perenne cv. Meltra, Citadel and Condesa oversown with T. repens cv. Retor in 1991 was given annual applications of 0, 50 or 100 kg N ha-1. Average annual dry matter (DM) yields were 14.66 and 13.76 t ha-1 year-1 for the clay and sandy soil, respectively. Yields increased with increasing N rate at both sites. Cutting frequency had no consistent effect on DM yield, and there was no significant interaction between N rate and cutting frequency. T. repens contents decreased with increasing N rate, reducing the DM yield in the cuts after the first in the fertilized treatments. Annual N yields were not affected by N application. The higher cutting frequency increased the T. repens content from 36 to 47% and the N yield from 458 to 524 kg ha-1, but did not affect the DM yield.


Author(s):  
Numan Kılıçalp ◽  
Mustafa Avcı ◽  
Hatice Hızlı ◽  
Rüştü Hatipoğlu

This research was conducted to determine forage yield, chemical composition, milk yield and milk composition in dairy cattle grazing on pasture established with species and mixtures of Perennial ryegrass (Lolium perenne, Bastion,PR), Orchardgrass(Dactylis glometata, Pizza,OG) and White clover(Trifolium repens, Huia,WC). In this research conducted for two years, the grazing experiment was carried out according to a change over trial design. For this purpose, a total of 6 Holstein Friesian cows (at the 2nd lactation and with an average of 520 ± 26 kg live weight) were used for two periods, each of which consisted of 30 days (8 days of adaptation and 22 days of the basis period). The milk nutritional composition of the animals (dry matter, fat and protein content) was determined in the last three days in the last five consecutive days of each lactation period. The acid detergent fiber (ADF) content of pasture obtained from Perennial ryegrass + White clover mixture (PRWC) was found to be lower than that obtained from the other two (PR and OG) pasture and Net Energy Lactation (NEL) content was found higher in the first grazing period in the first year. However, the effect of the investigated pastures on milk yield was not significant, but it was found that the effects on milk protein yield in the first year and dry matter of milk in the second year were significant. In the first year of grazing period, milk yield, milk fat yield and protein yield were found to be significant. The results of this study showed that under these operating conditions, the botanical composition of the pasture had no effect on the amount and composition of the milk, but the milk yield decreased as the vegetation period advanced.


1985 ◽  
Vol 40 (2) ◽  
pp. 267-277 ◽  
Author(s):  
T. A. Stewart ◽  
I. I. McCullough

ABSTRACTSilage cut twice annually (June and August) from a tetraploid red clover/grass sward and three times annually (May, July and September) from a low nitrogen (N) and high N perennial ryegrass/white clover sward was fed in proportion to dry-matter yield from each cut, over a 10-week period, each winter for 3 years to castrated male cattle of initial live weight 401 kg in year 1 and 425 kg in years 2 and 3. The silages were supplemented with 0, 1, 2 and 3 kg concentrate per head daily.Total dry-matter yield from the red clover/grass sward was similar to that from the perennial ryegrass/white clover sward (high N grass) receiving 360 kg N per ha but the digestibility, particularly of first cut material was much lower. Dry-matter production of the low N grass/white clover sward was 0·73 of high N grass sward and produced silages of similar digestibility and fermentation.Dry-matter intakes by the cattle were higher on the legume-based silages in years when clover made a worthwhile contribution to total yield, but this did not significantly improve utilization or animal performance compared with high N grass silage. Mean daily carcass gain per head on red clover/grass silage was 0·41 kg which was significantly less than the 0·61 kg on white clover/grass silage and 0·59 on high N grass (P < 0·001). Carcass output from red clover/grass silage was 618 kg/ha and 629 kg/ha from white clover/grass, both of which were significantly less than the 863 kg/ha from the high N grass silage (P < 0·001). Dressing proportion was also significantly poorer in animals fed red clover/grass silage compared with the other silage types.


1997 ◽  
Vol 48 (1) ◽  
pp. 111 ◽  
Author(s):  
D. K. Singh ◽  
P. W. G. Sale

A glasshouse experiment was carried out to determine how an increasing P supply influences the growth and survival of white clover plants subjected to a range of defoliation frequencies. Treatments involved the factorial combination of P application rate (0, 30, 90, and 180 mg/pot) to a P-deficient Krasnozem soil and defoliation frequency (1, 2, or 4 defoliations over 36 days). The survival of P-deficient plants was threatened by the most frequent defoliation; their leaf area declined owing to a reduction in leaf number and individual leaf size with each successive defoliation. Increasing the P supply to 180 mg/pot reversed this downward trend as the high P plants were able to maintain leaf area by increasing leaf size and number. Increasing the frequency from 1 to 4 defoliations over the 36 days also changed the form of the leaf dry matter response to added P, from an asymptotic to a linear response. The P requirement of white clover for maximum leaf yield therefore increased under frequent defoliation. This effect was also apparent for a range of morphological measurements including stolon elongation rate, leaf area, root mass, leaf number, and stolon number, where the magnitude of the P response was consistently greater for frequently defoliated plants. Exceptions included stolon mass, which responded more to P addition under infrequent defoliation.


1990 ◽  
Vol 41 (6) ◽  
pp. 1083 ◽  
Author(s):  
AA McGowan

It is often claimed that improved pastures grow better in the early years after initial establishment than after many years of fertilization and grazing. A pot experiment was conducted to compare the dry matter production of white clover and perennial ryegrass when sown into soil from old established pastures and into soil taken from adjacent roadsides which had not previously been cultivated, fertilized, sown or grazed. On 8 out of 10 sites, white clover growth was consistently poorer when sown into the paddock soil than into the roadside soil. The average growth on paddock soil from these 8 sites was only 61% that of growth on the roadside soils. With perennial ryegrass there was no similar depression; in fact, the overall average growth of grass on the paddock soils was 121% that on the roadside soils. The explanation for this difference in growth of clover on the two soil types was apparently not due to any difference in the N status of the clover plants, as at no harvest was this difference significantly reduced when N fertilizer was regularly applied to the clover. The economic importance of these findings depends on confirmation of the results in the field. Possible, but untested, explanations may lie in different levels of soil-borne pests and diseases, or a residual allelopathic effect of improved pasture species on the growth of clover on the old pasture soil.


1997 ◽  
Vol 37 (2) ◽  
pp. 165 ◽  
Author(s):  
J. S. Dunbabin ◽  
I. H. Hume ◽  
M. E. Ireson

Summary. Perennial ryegrass–white clover swards were irrigated for 3 years every 50, 80 and 120 mm of crop evapotranspiration minus rainfall (ETc–R) and water ponded on the soil surface for either 4, 12 or 24 h at each irrigation. Pasture production and clover content were highly seasonal, peaking in spring and autumn. Frequent irrigation increased dry matter production by an average of 56%. When irrigating at 50 mm ETc–R, dry matter production was decreased by ponding water on plots, 17% for 12 h ponding and 14% if ponded for 24 h. However, when irrigating at an interval of 80 mm ETc–R ponding increased dry matter production by 7% for 12 h ponding and by 25% for 24 h ponding. Ponding also increased production at an irrigation interval of 120 mm ETc–R by 25% for 12 h ponding but only by 2.4% for 24 h ponding. While these increases in dry matter production are large in relative terms the absolute increase in production is small. More water infiltrated per irrigation at longer irrigation intervals, and at longer ponding times. Frequently irrigated, rapidly drained swards used irrigation water most efficiently. The small gain in dry matter production achieved by prolonging ponding at longer irrigation intervals is an inefficient use of water and likely to recharge regional groundwater systems. Oxygen diffusion rate measurements suggested that ponding for as short as 4 h was likely to cause waterlogging stresses and that these stresses were higher when irrigating frequently. The relative increase in waterlogging stress by extending the period of ponding from 4 to 24 h was small.


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