A COMPARISON OF THE HERBAGE YIELD OF ITALIAN RYEGRASS AND TALL FESCUE MIXTURES IN THE SECOND AND THIRD YEAR AFTER SOWING

The annual yield of tall fescue was higher than that of Italian ryegrass in the third year after sowing, but the total yield of herbage from grass plus clover swards was similar.
In both the second and third year after sowing, the yield of herbage in the spring grazing was higher when fescue was used as the sown grass. The method of establishment of both tall fescue and Italian ryegrass affected the total and seasonal yield in the second and third year after sowing, but the magnitude of these effects was not nearly as marked as it was earlier in the life of the leys. In the second year after sowing, swards of both Italian ryegrass and tall fescue had a higher yield of total herbage and of white clover, and a lower ingress of unsown species, when established without a cover crop and grazed frequently in the year of sowing.
The inclusion of red clover did not increase total yield of DM in the second and third year after sowing, and it slightly decreased the yield of the tall fescue mixture in the third year following sowing when N was applied. S170 tall fescue was readily grazed by sheep in spring and autumn.
The apparent recovery of applied N varied with the mixture sown, and the management given during establishment.     

INTERACTIONS OF GRASS, CLOVER AND NURSE CROP IN THE SEEDING YEAR

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.     

A COMPARISON OF THE EFFECT OF ITALIAN RYEGRASS AND TALL FESCUE MIXTURES ON THE FOLLOWING CROPS OF KALE AND BARLEY

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.     

A comparison of perennial ryegrass‐ and tall fescue‐based swards with or without a cropping component for dairy production: Animal production,herbage characteristics and financial performance from a 3‐year farmlet trial

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.     

GRAZING MANAGEMENT FOR SEED PRODUCTION IN LEAFY STRAINS OF GRASSES

Leafy strains of five grasses were grown for seed and subjected to various cattle grazing treatments between October and April for three harvest years. The grasses were: S.143 cocksfoot, S.215 meadow fescue, S.170 tall fescue, S.59 red fescue and S.23 perennial ryegrass. All but S.59 red fescue (row crop) were studied as row and broadcast crops. The plots were sown under an arable silage crop and received top dressings of nitrogenous fertiliser every year. Yield of seed, and also quantity of herbage in winter, were measured.
October grazing in the seeding year reduced the first crop of seed in all species except ryegrass. Grazing in December improved the yield of meadow fescue throughout the experiment, and of cocksfoot, tall fescue and red fescue after the first year. Several factors might operate to bring about this effect; suggestions are made for further investigation. Repeated grazing from December to March tended to reduce vigour, and so to offset the advantage of removing autumn-grown herbage. Grazing at intervals from December to late April seriously reduced yield in all species. Tall fescue and red fescue, early flowering species, were most seriously affected, meadow fescue and perennial ryegrass least. Cocksfoot and tall fescue yielded more seed when grown in 2-ft. rows than when broadcast. Meadow fescue and perennial ryegrass did not. The yield of meadow fescue was less affected by adverse conditions than cocksfoot.     

Performance and quality of tall fescue (Festuca arundinacea Schreb.) and perennial ryegrass (Lolium perenne L.) and mixtures of both species grown with or without white clover (Trifolium repens L.) under cutting management

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.     

Effect of fertilizer nitrogen on six-year-old red clover/perennial grass swards

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.     

THE EFFECT OF COMPANION GRASS AND SEED RATE ON THE PRODUCTIVITY OF A TALL-FESCUE SWARD

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.     

Productivity of mixtures of Italian ryegrass and red clover

Two red clover ( Trifolium pratense ) cultivars, Red Head (tetraploid) and Kuhn (diploid), were sown at a seed rate of 13 kg ha⁻¹ either alone or in mixture with Italian ryegrass ( Lolium multiflorum ) cv. RvP sown at seed rates of 10, 15, 20 or 30 kg ha⁻¹. RvP was also sown alone at a seed rate of 30 kg ha⁻¹ and received nil or 300 kg ha⁻¹ fertilizer a⁻¹ fertilizer N. All plots were established using the barley cultivar Midas sown at a seed rate of 100 kg ha⁻¹ as a nurse crop.
Neither clover cultivar nor ryegrass seed rate significantly influenced either dry matter harvested or botanical composition over the 3 harvest years. On average over all years the grass-clover mixtures produced 75% of the yield of the N-fertilized RvP, 125% of the clover monocultures and 225% of the unfertilized RvP. The red clover contribution to the total dry matter harvested of the mixtures averaged 45–60%. The dry matter concentrations of the mixtures were considerably higher than those of the pure clover stands. In the third year yields were markedly reduced in comparison with those in the first and second years.
It was concluded that Italian ryegrass can be a suitable companion grass for red clover. Its superior yielding capacity over other grasses such as perennial ryegrass or timothy under a conservation management can be coupled to advantage with red clover to give a sward which Is essentially stable, at least over a 2- to 3-year cropping period, although giving slightly reduced yields in the third year. Italian ryegrass-red clover mixtures, without the use of fertilizer N, can produce high DM yields of good quality herbage.     

THE DIGESTIBILITY AND PRODUCTIVITY OF SELECTED HERBAGE VARIETIES

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.     

Species interactions in a grassland mixture under low nitrogen fertilization and two cutting frequencies: 1. dry‐matter yield and dynamics of species composition

Four‐species mixtures and pure stands of perennial ryegrass, tall fescue, white clover and red clover were grown in three‐cut and five‐cut systems at Ås, southern Norway, at a low fertilization rate (100 kg N ha^?1 year^?1). Over a three‐year experiment, we found strong positive effects of species diversity on annual dry‐matter yield and yield stability under both cutting frequencies. The overyielding in mixtures relative to pure stands was highest in the five‐cut system and in the second year. Among the possible pairwise species interaction effects contributing to the diversity effect, the grass–grass interaction was the strongest, being significant in both cutting systems and in all years. The grass–legume interactions were sometimes significant, but no significant legume–legume interaction could be detected. Competitive relationships between species varied from year to year and also between cutting systems. Estimations based on species identity effects and pair‐specific interactions suggested that the optimal proportions of red clover, white clover, perennial ryegrass and tall fescue in seed mixtures would have been around 0·1, 0·2, 0·4 and 0·3 in the three‐cut system, and 0·1, 0·3, 0·3 and 0·3 in the five‐cut system.     

Micronutrient concentrations in common and novel forage species and varieties grown on two contrasting soils

We investigated differences between forage species with regard to micronutrients that are essential to sustain livestock health. Five grasses (timothy, perennial ryegrass, meadow fescue, tall fescue and cocksfoot), three legumes (red clover, white clover and birdsfoot trefoil) and four forbs (ribwort plantain, salad burnet, caraway and chicory) were grown on one micronutrient‐poor/low pH soil and one micronutrient‐rich/high pH soil (outdoor pot experiment). In addition, six grasses (timothy, perennial ryegrass, meadow fescue, tall fescue, Festulolium hybrid and cocksfoot) and one legume (red clover) were field‐grown on the micronutrient‐poor soil. Of the twelve pot‐grown species, herbage of chicory, red clover and white clover generally had the highest micronutrient concentrations (maximum Co, Cu, Fe and Zn concentrations were 0·23, 9·8, 233 and 109 mg kg^?1 DM, respectively), except for Mo, which was highest in the clovers (10·6 mg kg^?1 DM), and Mn, which was highest in cocksfoot (375 mg kg^?1 DM). Soil type had the strongest effect on plant Mo and Mn concentrations. We also investigated differences in micronutrients between varieties, but they were generally few and negligible. The results indicate that choice of forage species is of major importance for micronutrient concentrations in herbage and that soil type exerts a major effect through pH. Forage of chicory, red clover and white clover generally met the requirements of high‐yielding dairy cows with regard to most micronutrients; therefore, diversification of seed mixtures so as to include these species could increase micronutrient concentrations in forage.     

Establishment and production of common sainfoin (Onobrychis viciifolia Scop.) in the UK. 2. Effects of direct sowing and undersowing in spring barley on sainfoin and sainfoin-grass mixtures

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.     

Effect of seed rate of red clover and of companion timothy or tall fescue on herbage production

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.     

Some differences between eight grasses within the Lolium-Festuca complex when grown in conditions of severe water shortage

Differences between eight related grasses within the Lolium-Festuca complex in conditions of severe water shortage were investigated. Transparent covers were used to restrict the access of rain to field plots of pure stands of Westerwolds ryegrass ( Lolium multiflorum var. Westerwoldicum), Italian ryegrass ( L. multiflorum ), hybrid ryegrass ( L. multiflorum × L. perenne ), perennial ryegrass ( L. perenne ), meadow fescue ( Festuca pratensis ), Italian ryegrass × meadow fescue, perennial ryegrass × meadow rescue, tall fescue ( Festuca arundinacea ) and three mixtures (Italian ryegrass with perennial ryegrass; Italian ryegrass with tall fescue; perennial ryegrass with tall rescue) grown in west Wales. Westerwolds ryegrass and Italian ryegrass died out after 12–15 months of exclusion of rain; meadow fescue, meadow rescue × ryegrass hybrids and perennial ryegrass died out after ≊ 2 years of exclusion of rain; tall rescue was still alive after 4 years of exclusion of rain. During the 2 years after the year of sowing, the loss of water from the top 1 m of soil was greater with tall rescue than with the other grasses. Tall fescue and perennial ryegrass had a low rate of leaf expansion, a small increase in length of exposed leaf sheath and a high weight per unit area of emerging leaf blade. Tall rescue had a greater number and weight of roots than the other grasses, particularly in the 50–100 cm layer of soil, on an adjoining, uncovered site. The order of suitability of the eight grasses for conditions of severe water shortage appears to be tall fescue > perennial ryegrass > perennial ryegrass × meadow rescue, meadow fescue, Italian ryegrass × meadow rescue, hybrid ryegrass > Italian ryegrass > Westerwolds ryegrass.     

Establishment, persistence and nitrogen fixation of white clover and marsh trefoil on blanket peat

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.     

SOME EFFECTS OF GRAZING MANAGEMENT ON THE YIELD AND ITS COMPONENTS OF SOME PASTURE GRASSES

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.     

THE SPECIES PREFERENCES OF GRAZING HORSES

Palatability studies of 29 species of grasses, legumes and herbs, and two seeds mixtures, were conducted using three replicates of each species. Crossbred ponies and a few Thoroughbreds were obserred and timed for a total of 260 hours grazing. The results were analysed and sbowed small statistical differences between replicates, between tbe 2 years observed and between horses; and highly significant differences (P<0.001) between certain species. The most palatable was a clover-rich mixture. Tbe pasture varieties of perennial ryegrass were significantly more palatable tban S24, and as palatable as timothy and cocksfoot Alta tall fescue, crested dogs tail and wild white clover were palatable. Some herbs, red clover, brown top, red fescue and meadow foxtail were tbe least palatable. Dandelion, ribgrass and yarrow were palatable herbs.     

Potential pasture production in the uplands of Wales

Only a very limited number of species, including red fescue (Festuca rubra) , perennial ryegrass ( Lolium perenne) , timothy (Phleum protense) and white clover (Trifolium repens) are considered as suitable for wet hill land. Detailed comparison of red fescue, perennial ryegrass and timothy on contrasting acid brown earth and stagnogley soils from 1966 to 1969 at Pant-y-dŵr Hill Centre (305 m OD) highlighted the advantages of red fescue in annual DM production and its more even distribution over a longer growing season but also indicated drawbacks of slow initial establishment and lower feed quality. In vitro DOMD of red fescue averaged 645 g kg⁻¹ over the year compared with 690 g kg⁻¹ for perennial ryegrass and timothy. Assessment of a narrow range of species under surface seeding conditions on a stagnogley soil from 1971 to 1975 confirmed the value of red fescue in DM production and persistence. The results are discussed in relation to the characteristics required in herbage species for hill land improvement.     

Productivity of red clover grown alone and with companion grasses over a four-year period

Six red clover cultivars, three diploid—Essex, Sabtoron and Violetta—and three tetraploid— Teroba, Red Head and Hungaropoly—were sown alone and with each of three companion grasses—timothy (S48), tall fescue (S170) and perennial ryegrass (S24). The productivity and persistency of the red clover cultivars were compared over 4 years. Dry matter (DM) yield, DM digestibility and the crude protein (CP) concentration were assessed and botanical analyses conducted on herbage samples from each treatment at each of three harvests per annum. Annual fertilizer application consisted of 165 kg P and 312 kg K ha^-1. Comparing clover cultivars alone Essex was significantly less productive and less persistent than the other five cultivars. Yield and persistency of the five other cultivars did not differ markedly within years with the exception that the diploids were significantly less productive than the tetraploids in the fourth year. Over all 4 years mean annual total DM and clover DM yields of the five cultivars were between 12·2 and 13·2 t ha^-1 and between 9·2 (79·2% of total DM yield) and 10·2 (83·2%) t ha^-1 respectively, and differences were not significant. Up to the end of the third year there was little or no advantage gained by the inclusion of a companion grass, annual total DM yields being between 11·2 and 14·2 t ha^-1 for clover alone and between 10·2 and 14·2 t ha^-1 for clover-grass mixtures. In the fourth year there was an overall tendency for the yield of the clover alone to be lower, between 7·2 and 12·2 t ha^-1, than that of the clover-grass mixture, between 8·2 and 13·2 t ha^-1, and this was more pronounced with the diploid than with the tetraploid clover cultivars. Sown with companion grasses, Essex and Hungaropoly were lower in yield and in contribution than the other cultivars over the 4 years. The influence of the companion grass on total dry matter yield showed that the contribution of timothy was low relative to that made by tall fescue and perennial ryegrass. Perennial ryegrass made the most varied contribution from year to year. Tall fescue was the most consistent contributor with all clover cultivars and at the end of 4 years both yield and clover-grass balance had not changed materially. No pronounced differences in DM digestibility were evident between treatments. Crude protein concentration of the pure clover was similar to that of the clover-timothy treatments and both would appear to be superior to either the clover-perennial ryegrass or clover-tall fescue mixtures. It is considered that red clover dominant swards are suitable for use under a cutting regime and can provide high yields of DM at a low cost for up to 4 years. Such swards are self-sufficient in N and in addition soil N accumulation can be exploited in the production of succeeding crops.