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1.
Tall fescue and Italian ryegrass mixtures react differently to management in the year of sowing. The decrease in yield of tall fescue and the increase in growth of red clover, caused by the use of a cover crop, was still evident in the following year. In both the spring grazing and total yield of the first harvest year, the Italian ryegrass/ white clover mixture was better than the tall fescue/white clover mixture when a cover crop was used. The reverse trend was recorded when the grass plus clover was sown without the cereal. In general, the addition of red clover to the tall fescue/ white clover, or Italian ryegrass/white clover mixture, increased the yield, but the magnitude of the increase was modified by management during establishment. The increase in total herbage yield and the reduction of white clover growth due to nitrogen application were both related to management in the year of sowing. Consideration should thus be given to method of establishment in the assessment of herbage seeds mixtures.  相似文献   

2.
Tall fescue S170 and Italian ryegrass S22, slow- and rapid-establishing grasses, respectively, were sown either with white clover or with a mixture of red and white clovers, with or without a companion- or cover-crop, and with or without nitrogen. Swards established without a cover-crop were grazed frequently or cut infrequently; swards undersown with the oat crop were grazed once in the autumn. In the year of sowing tall fescue/clover mixtures produced yields similar to those of Italian ryegrass/clover swards. Tall fescue proved sensitive to competition, even from red clover, during establishment and sowing under a cover-crop is therefore not recommended. The yield of red- and white-clover was increased when sown under a cover-crop and when cut infrequently, compared with frequent grazing by sheep. The growth of white clover was greatly reduced by adding red clover to the mixture, particularly under a cover-crop and when defoliation was infrequent, but red clover increased total yield. The effect of N applied to the seed-bed varied with the method of establishment. Cereal yield was reduced under dry conditions by undersowing with a mixture containing red clover.  相似文献   

3.
The effects of preeropping with Italian ryegrass and tall fescue mixtures on marrow-stem kale (1st test crop) and barley (2nd test crop) were measured. Application of N to the grass/clover swards reduced the yield of DM, P, K, Na, Mg, crude protein and also the percentage crude protein in the kale test-crop. Following the tall fescue swards, the yield of DM, P, Na, Ca, Mg and E, crude protein and percentage crude protein in the kale were lower than after the Italian ryegrass swards. These effects were particularly evident in the kale stem. Interactions occurred which involved the method used to establish the herbage mixtures, the application of N to the swards and of fertilizers to the kale. These effects were complex, but the method of sward establishment could clearly affect the following kale crop grown several years later. The influence of grass swards on the second test-crop (spring barley) was much smaller than on kale. Precropping with Italian ryegrass or using a cover crop during grassland establishment reduced 1000-grain weight of barley. The crude protein percentage in barley grain was reduced by the compound fertilizer applied to the previous kale crop, particularly when no cover crop had been used during establishment of the herbage mixtures. The converse of these effects was recorded in the crude-protein percentage of the straw of the barley test-crop.  相似文献   

4.
Perennial ryegrass/white clover swards have some limitations in temperate grazed dairying systems. This study tested the hypothesis that farmlets based on alternative species would be equally or more profitable than those perennial ryegrass‐based, and would produce more herbage in summer‐dry conditions. Six farmlets were established; three with perennial ryegrass‐ and three with tall fescue‐based swards. For each grass species, one farmlet was solely based on grass‐clover swards while the other two had either chicory‐red clover or lucerne crops planted on 20%–25% of the area. Animal‐ and herbage performance‐related variables were measured for 3 years, and calculated financial performance was evaluated. Using tall fescue improved total annual herbage yield compared with perennial ryegrass, but animal production and operating profit were lower. This was likely due to the reduced yield and nutritive value of tall fescue during spring and an associated decline in daily milksolids production. The deficit in spring milksolids production was never recovered, despite greater herbage production from tall fescue during summer/autumn. Incorporating chicory‐red clover or lucerne crops reduced both annual herbage and milksolids production. This reduced farm income, while increasing operating expenses as the farmlets required crop renewal and more purchased supplementary feed to maintain feed supply. Under the conditions of this study (i.e., partial irrigation, high nitrogen supply), changing the forage base from perennial ryegrass to tall fescue did not improve animal production or profitability, nor did incorporation of crops on 20%–25% of the farmlet area.  相似文献   

5.
An experiment was conducted to measure the effects of differrat ryegrass companion grasses and red-clover varieties on the productivity of red-clover swards. Three silage harvests per year were taken over a 2-year period. The addition of a companion grass increased total herbage yields; S24 perennial ryegrass gave the highest herbage yield over the two years, followed by Reveille perennial ryegrass. Because of lack of persistence, Tetila Italian ryegrass yielded poorly the second year. A companion grass had little effect on red-clover yields in the mixed swards but improved percentage digestibility of the OM of the total herbage and lowered the CP percentage. Its presence also reduced the ingress of unsown species. The variety of red clover used had little effect on total herbage yields or red-clover yields in the first harvest year. In the second year, Hungaropoly and Tilo persisted better and so gave higher total herbage yields and red-clover yields than Dorset Marl or Essex. The fall in total herbage yields from the first to the second year was entirely due to a fall in red-clover yield since yields of the ‘non-red clover’ fraction of the total herbage increased. A red-clover/grass sward may have advantages over a pure red-clover sward nutritionally, for silage-making and for its effect in diluting the oestrogenic activity of a pure clover sward. A major reappraisal of the role and potential of red-clover swards in the UK is warranted because of their many valuable attributes, particularly their ability to give high herbage yields of high nutritive value without the addition of fertilizer N. The improved persistency of some of the tetraploid varieties of red clover enhances the value of the plant.  相似文献   

6.
Three diploid red clover cultivars—Sabtoron, Violetta and Essex—and three tetraploid, Hungaropoly, Teroba and Red Head, were sown separately in pure culture and with each of three companion grasses: timothy (Aberystwyth S48), tall fescue (Aberystwyth S170) and perennial ryegrass (Aberystwyth S24).
The effects of fertilizer N on yield and on clover/grass ratio over a 2-year period (seventh and eighth harvest years) subsequent to 6 harvest years during which no N fertilizer was applied were investigated. The data for productivity and persistence have already been published (McBratney, 1981; 1984).
Application of fertilizer N increased DM yields in the eighth year. In this year, the highest yield, 11·9t ha-1, averaged over the six clover cultivars, was given in association with tall fescue. Tall fescue contributed 90% of this yield. Clover content continued to decrease in all swards but the decrease was greatest in the swards receiving fertilizer N. The yield of clover DM averaged over the six cultivars under N treatment declined from 5·6t ha-1 in the seventh year to only 0·4t ha-1 in the eighth year.
The results from this trial demonstrate the potential of red clover sown either pure or in mixture with a suitable perennial grass, to maintain high output of quality herbage over a 6-year period without the aid of fertilizer N. They further demonstrate that following decline in red clover content, both herbage yield and quality may be restored by the application of N fertilizer, particularly where the clover was seeded with a highly productive companion grass.  相似文献   

7.
Seven species or varieties of grass, and a mixture of 3 of them, were sown in pure swards and treated with 4 levels of nitrogenous fertilizer (0,17·5, 35 and 70lb N per acre per cut). Each species, and the mixture, was also sown with white clover. The experiment was cut 4 or 5 times per year. The effect of fertilizer on the yield of each grass was compared with the effect of clover on the yield of the grass/clover swards. Mean annual yields showed an approximately linear response to N; there was a small but significant fall in response to the highest level of N. Response among the species ranged from 20 to 30 Ib of dry matter per Ib N applied for the intermediate level of fertilizer and from 14 to 23 Ib for the final increment of fertilizer.
S37 cocksfoot, S48 timothy, S24 ryegrass, and a mixture of these grasses, were high yielding and responded well to fertilizer N; Irish ryegrass and Agrostis tenuis were less productive and gave poorer responses to N. S215 meadow fescue and S23 ryegrass were intermediate in yield and response.
There were no significant differences between the annual yields of the 8 grass/clover mixtures; the yields of the grass and clover components of each mixture were inversely related. The effect of clover on the yield of the grass/clover mixtures was estimated to be equivalent to the effect of an annual application of 205 lb N per acre to Agrostis tenuis and 120 lb N to S48 timothy. The fluctuations in annual yields were greater with grass/ clover mixtures than with grass swards receiving N.
The yields of grasses when sown with clover were in similar order to their yields when sown pure; but whereas the latter tended to fall from year to year, the yields of the grass components of mixtures (except Irish ryegrass) did not.  相似文献   

8.
The effects of sowing from 10 to 50 lb/acre of tall-fescue seed on plant establishment and on the annual and seasonal distribution of DM yield of tall fescue and its companion grasses were measured through two growing seasons. Increasing the seed rate increased plant numbers per unit area and decreased per cent establishment. Adding Scots timothy as a companion grass depressed both plant number and per cent establishment. S37 cocksfoot and New Zealand perennial ryegrass reduced both still further. Total annual dry-matter production was relatively unaffected by varying either the seed rate or the companion grass. The contribution of tall fescue to total production was highest when sown alone and was successively reduced by timothy, perennial ryegrass and cocksfoot. When sown alone there were only slight differences in contribution of tall fescue due to seed rate. With any companion grass the contribution from tall fescue increased with increasing seed rate. Early growth was not reduced by modifying seed rate but was reduced by all the companion grasses. It is concluded that increasing the seed rate of tall fescue above 30 lb is not justified, that Scots timothy can be sown at 3 lb/acre with tall fescue without affecting total production or early growth of the mixture, with the advantages of control of unsown species and improved palatability of the herbage.  相似文献   

9.
White clover (cv. S184 or Blanca) or marsh trefoil (cv. Grasslands 4703 or Grasslands Maku) were sown alone and in combination with a companion grass (tall fescue, red fescue, perennial ryegrass or ryegrass cleanings) on a peat area of hill land originally dominated by Juncus articulatus and Molinia caerulea.
Lime and ground rock phosphate were applied in 1973, the area rotavated to a shallow depth and seeds sown in May 1974. No fertilizers were applied except at sowing time and two harvests were taken per annum for 4 years.
Differences in yield and legume content between companion grass treatments were small. After the first full harvest year Blanca swards usually had the lowest DM yields and those containing Maku the highest. The contribution of marsh trefoil to total herbage yield increased from 4·2% in 1975 to 22% in 1978, whereas white clover decreased from 4·2 to 1·2%. Legume yields in 1978 were less than half those in 1977. Overall, N yields were low, Maku swards fixing most N estimated to be highest in 1977 at 35 kg ha-1.
It is concluded that marsh trefoil grows well on upland peat but more information on its response to grazing is necessary before conclusions can be drawn about its value in hill land improvement.  相似文献   

10.
The effects of autumn management and nitrogenous manuring on the production of early spring grass were studied from 1954 to 1957 on farms throughout England and Wales.
The most important management factor influencing spring yields was the application of spring nitrogen. In the early spring 6 to 10 lb. of dry matter were produced per lb. of nitrogen applied. Autumn nitrogen increased herbage yields in the auttimn by 8 to 17 lb. of dry matter per lb. of nitrogen applied.
Italian and perennial ryegrass responded well to autumn nitrogen but it was important to graze off the extra growth fairly quickly to prevent the sward becoming too open. The yield of ryegrass swards which received spring nitrogen were very much higher if they were grazed during the previous September and October than if they had been rested during those months.
In two years neither the autumn management nor alumni fertilizer appeared to influence the spring yields of cocksfoot, timothy or meadow fescue swards, in one year, however, when autumn growth was poor, autumn nitrogen and resting resulted in slightly better yields on these swards in the following spring.
It is suggested that resting swards during September and October to build up "reserves" is relatively unimportant in relation to the yields of grass in the following spring.  相似文献   

11.
The yields of two varieties of lucerne sown alone and in associalion with each of three grasses were compared with similar red clover/grass mixtures over the period 1953–56 under two levels of nitrogenous and potassic fertilizers and two cutting treatments. The main object of the experiment was to gain a wider knowledge of the productivity and chemical composition of lucerne sown alone, and in mixtures, under relatively high rainfall conditions.
The highest production was obtained from Du Puits and its mixtures, which exceeded Grimm and S 123 red clover mixtures. The yields of the lucerne/grass mixtures were not significantly better than those of the pure sown lucerne. Under the most favourable conditions for lucerne, Du Puits eliminated practically all the sown grasses, viz., S 23 ryegrass, S 51 timothy and S 215 meadow fescue.
The application of nitrogen encouraged the growth of the grasses, often at the expense of the legume, especially the slower growing Grimm and S 123. The effect on Du Puits was less marked, but in no case was there a stibstantial increase in actual legume yield. Increasing the level of potassium, although not immediately affecting the yield, proved beneficial to lucerne survival in the later years. The protein yield from the best lucerne plots was found to be double that from pure grass swards heavily fertilized with nitrogen.
Three cuts of lucerne in the first two harvest years had a disastrous effecl on the carry-over of lucerne from the second to the third year. Both varieties of lucerne and their mixtures behaved in a similar fashion, although S 123 red clover appeared to be indifferent to these conditions. It is suggested that the cause of this was the unfavourable weather experienced in 1954.  相似文献   

12.
The magnesium contents of mixed herbage and four individual grass and clover species were studied under four treatments—control, magnesium sulphate, magnesian limestone and carboniferous limestone.
The magnesium values were lowest in the spring and early summer and then increased to maximum values by the autumn. The seasonal variations, however, differed appreciably from year to year.
The effect of magnesian limestone on the magnesium content of mixed herbage was relatively small in the year of application, but increased during the following years and reached a maximum in the fourth year after application. The increase in magnesium uptake from the magnesium sulphate treatment was small after the first year, whilst carboniferous limestone slightly depressed the magnesium content. This depression, however, was very small and probably of no practical significance.
The magnesium content of red clover was about 50% higher than that of Italian ryegrass, cocksfoot and white clover. In the second year after application magnesian limestone had a much greater effect on the magnesium content of the clovers than on that of the grasses.  相似文献   

13.
An experiment was conducted over 3 years (1983-85) to assess the performance of Holcus lanatus German Commercial and cv. Massey Basyn compared with Lolium perenne cv. Perma on a gley soil under sheep grazing in the Scottish uplands. All grasses were sown together with Trifolium repens cv. Grasslands Huia. The swards were rotationally grazed at similar herbage allowances. During the first harvest year, the swards were grazed hard to a low mass (500 kg DM ha−1). In the second harvest year, post-grazing herbage masses of 500 and 1000 kg DM ha−1 were compared.
Perma ryegrass had a higher level of herbage production than both H. lanatus cultivars in the first and second harvest years after sowing and hence had a greater number of sheep grazing days. The ryegrass sward consisted of 25% more green sown grass (85 cf. 60%) but 12% less white clover (4 cf. 16%) compared with both H. lanatus cultivars in the establishment and first harvest years. The persistence of all three grasses was poor although ryegrass had a higher presence (36%) than either Massey Basyn (22%) or German Commercial (13%) at the end of the. second harvest year.
At a similar herbage allowance, there were no significant differences in the herbage intake and liveweight gain of sheep. Ryegrass had a higher organic matter digestibility and lower neutral and acid detergent fibre and lignin contents than either of the H. lanatus cultivars.
In the second harvest year, although herbage production was greater at the higher herbage mass, there was no difference in the proportion of sown grass.
It was concluded that ryegrass is a superior grass to H. lanatus on upland soils with high N status, moderate P status and a high pH.  相似文献   

14.
Much of the published digestibility data refer to swards grown in the south of Britain. In order to study digestibility curves in a more northerly latitude, several pure swards were established in the west of Scotland in 1962 and 1963. Varieties included S22 and Tetila Italian ryegrass, S37 cocksfoot, S170 tall fescue, S215 meadow fescue, Scots timothy, English broad red clover, and SI00 white clover. In addition to primary growth in vitro digestibility, the effect of various cutting managements on digestibility and productivity was measured. Flowerhead emergence was delayed, with the result that the digestibility curve was later than is reported from southern Britain. Highest yields of digestible organic matter were obtained from the less frequent cutting regimes, but the mean digestibility of the herbage was lower. Pre-dictibility of herbage digestibility is desirable as the basis of a reliable and planned herbage utilization programme, particularly for conservation.  相似文献   

15.
Three diploid—Sabtoron, Violetta and Essex—and three tetraploid—Hungaropoly, Teroba and Red Head—red clover cultivars were sown alone and with each of three companion grasses—timothy (S48), tall fescue (S170) and perennial ryegrass (S24). The productivity and persistence of the red clover cultivars were compared. Results obtained over the first four harvest years were presented in an earlier paper (McBratney, 1981) and this paper presents results from the fifth and sixth (final) harvest years.
The low yield obtained in the fifth and sixth year from Essex under each seeding treatment indicated a deterioration in its persistency or vigour or both. In the fifth year the remaining two diploids, Sabtoron and Violetta, were as highly productive and persistent as the three tetraploids but in the sixth year the decrease in productivity was greater in the diploids than in the tetraploids. In the fifth year Teroba, the highest yielder, produced 9 8 t total DM ha−1 over all seeding treatments of which 73% was clover DM; in the sixth year Teroba was again highest yielding, producing 9.3 t ha−l with 67% clover content. Tall fescue was the most consistent companion grass in the mixed swards, in the sixth year contributing 53% grass DM to the total 8 8 t DM harvested ha−1.
The trial demonstrates the potential of a number of red clover cultivars grown either pure or with a suitable perennial grass to achieve and maintain a high output of herbage of good quality over a period of 6 years without any application of fertilizer N. The practical agricultural implications of using red clover are discussed.  相似文献   

16.
A study was made to determine the effects of grazing to a height of 1 in. when the swards reached heights of 3 and 9 in. on the dry matter production, LAI, tillering and rate of leaf production of new and old tillers in the spring–summer and autumn–winter seasons of 3 pasture species growing in association with white and red clovers. In both seasons the herbage yield under 9–1 management was higher than that under 3–1 and was significantly greater in the spring-summer season. Differences in DM production between cocksfoot, tall fescue and Ariki ryegrass failed to reach significance.
Light utilization under the 2 management systems was considered to be inefficient. In the autumn-winter period there was a linear relationship between the LAI and DM production in all treatments.
The rate of leaf production per tiller was significantly higher in cocksfoot than in ryegrass and tall fescue in both seasons.
New tillers had a significantly higher rate of leaf production than old tillers in the spring-summer period, but not in autumn-winter. The numbers of grass tillers and rooted nodes of clover were significantly higher under 3–1 than under 9–1 and were influenced by season.  相似文献   

17.
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.  相似文献   

18.
Seven species or varieties of grass, and a mixture of 3 of them, were sown in pure swards, treated with 4 levels of nitro-chalk (0, 17·5, 35, and 70 Ib N/ac/cut) and cut 4 or 5 times each year. Each species and the mixture were also sown with white clover, and the effect of fertilizer N on the yield of N in each grass was compared with the effect of clover on the yield of N harvested from the grass/clover swards.
The regression line for response in yield of N with increasing levels of fertilizer N showed slight, but significant, upward curvature. The grasses differed in their uptake of N from the soil, S37 cocksfoot and S48 timothy showing relatively high uptakes, and the ability of each grass to take up fertilizer N was usually related to its uptake of N from the soil. Differences in the yield of dry matter between the species, at a similar level of N, are discussed, and it was concluded that perennial ryegrasses were most efficient and Agrostis tenuis was least efficient in using the N taken up in the production of DM.
In general, there were no significant differences between the yields of N of the grass/clover mixtures; the N yields of the grass components were significantly different and tended to be inversely related to the N yields of clover.
Grasses which gave high yields of N with fertilizer were also high yielding when grown in association with clover. Pure grass swards required more than 200 Ib fertilizer N/ac/yr in order to yield the same amount of N as the grass/clover swards. The amount of N estimated to have been derived by grass from clover (indirect effect of clover) increased each year; it was highest with S37 cocksfoot and lowest with Irish perennial ryegrass, averaging 46 and 23 Ib N/ac/yr, respectively.  相似文献   

19.
Tetraploid red clover (cv. Hungaropoly) was sown at seed rates of 6,12 or 18 kg ha?1 alone and in mixture with timothy (cv. Scots) at 2, 4 or 6 kg ha?1 or with tall fescue (cv. S170) at 6,12 or 18 kg ha?1. Two ‘silage’ crops and an ‘aftermath grazing’ crop were harvested in 2 successive years. In harvest years 1 and 2, total herbage production levels of 11.12 and 7.47 t dry matter (DM) ha?1 respectively were obtained from pure-sown red clover compared with 11.84 and 8.78 t DM ha?1 for red clover-timothy and 12.23 and 9.64 t DM ha?1 for red clover-tall fescue. Corresponding red clover production levels were 10.93 and 5.30 t DM ha?1 (red clover swards), 8.04 and 3.131 ha?1 (red clover-timothy), and 6.42 and 109 t ha?1 (red clover-tall fescue). Total herbage organic matter digestibility was improved by the timothy companion grass but not consistently by the tall fescue, whereas crude protein (CP) concentration was decreased by the addition of either grass. Increased seed rate intensified these effects, as well as the general effect of the companion grass in depressing red clover DM, digestible organic matter (DOM) and CP production. Total herbage DM, DOM and CP were not markedly affected by increasing red clover seed rate but red clover DM, DOM and CP were increased as red clover seed rate was raised, due to increases in the red clover component. The potential for silage cropping of red clover swards was confirmed but there was advantage in sowing a companion grass. Taking yield and quality parameters into consideration, timothy proved a better companion than tall fescue. A seed rate of 2 or 4 kg ha?1 timothy and 12 kg ha?1 red clover proved the most satisfactory.  相似文献   

20.
The dry matter (DM) yield and herbage quality of swards of sainfoin ( Onobrychis viciifolia ), meadow fescue ( Festuca pratensis ,) and tetraploid perennial ryegrass ( Lolium perenne ) grown in monocultures and in four sainfoin:grass mixtures (0·33 sainfoin:0·66 meadow fescue, 0·66 sainfoin:0·33 meadow fescue, 0·33 sainfoin:0·66 perennial ryegrass and 0·66 sainfoin:0·33 perennial ryegrass), established by direct sowing or undersowing in spring barley, were investigated over 3 years in a field experiment in the UK. Direct sowing produced a mean yield across all species and mixtures of 1·8 t DM ha−1 in the establishment year, whereas undersowing produced no measurable yield except for that of the spring barley. Undersowing reduced the yields of sainfoin and sainfoin-grass mixtures in the first full-harvest year but not in the second. The annual yield of a monoculture of sainfoin was 7·53 t DM ha−1 and that of sainfoin-grass mixtures was 8·33 t DM ha−1 averaged over 3 years. Both sainfoin and the sainfoin-grass mixtures had higher annual DM yields than the grass monocultures. The mixture of 0·66 sainfoin:0·33 meadow fescue gave the highest mean annual yield (9·07 t DM ha−1) over the 3 years. There was a higher proportion of sainfoin maintained in mixtures with perennial ryegrass than with meadow fescue. The proportion of sainfoin in sainfoin–meadow fescue mixtures declined from 0·62 in the first year to 0·32 in the third year, whereas the proportion in sainfoin–perennial ryegrass increased from 0·48 in the first year to 0·67 in the second year and remained stable in the third year.  相似文献   

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