bluuebunny/crossref_metadata_2025 huggingface dataset:
THE RESIDUAL VALUE OVER THIRTEEN YEARS OF ROCK PHOSPHATE AND SUPERPHOSPHATE ON A PERMANENT GRASS SWARD
Authors: Edwards G. H. A.
Published: April 2006

Over 13 years, 12 cwt/ac of ground rock phosphate (29% P2O5) were applied to an old grass sward, either completely in the first year or in equal amounts in each of the first 4 years; alternatively, 18 cwt superphosphate/ac were applied either in 3 equal amounts at 4–yearly intervals, or in equal amounts annually over the first 12 years.

In the first year, the larger dressing of superphosphate gave the best response, measured as fresh herbage cut in mid–July each year, but during the next 7 years all methods of application gave similar yields. Dressings of rock phosphate gave progressively poorer response after 7 years and plots so treated were not significantly better than the control in the final year. At the end of the experiment, plots receiving annual applications of superphosphate yielded most herbage and those which had received superphosphate at 4–yearly intervals still showed a significant response. Phosphate in rock phosphate applied as a single dressing was two–thirds as effective over an 8–year period as that in superphosphate applied annually.

The small difference over 12 years in phosphate uptake from 3 dressings of superphosphate compared with its equivalent in annual applications suggested that little phosphate fixation was taking place. The fact that a single dressing of rock phosphate was able to maintain yields and phosphate uptake close to that obtained from annual applications over 7 years supports this and suggests that the failure to utilize one third of the phosphate in rock phosphate was mostly due to initial insolubility.
THE ALTITUDINAL ZONING OF GRASSLAND AND SOILS ON THE BRECON BEACONS IN SOUTH WALES
Authors: Crampton C. B. , Jones R. Garrett
Published: April 2006

The altitudinal sequence of soils occurs lower on the north than on the south face of the Brecon Beacons where the highest slopes of the north face are occupied by shallow, strongly leached rankers. Except on lower slopes, Vacciniun, Calluna and Nardus dominate the flora associated with each soil type. Unlike their distribution elsewhere, Rhytidiadelphus and Hypnum are associated with gleyed soils. It is suggested that exposure and inaccessibility have limited hill grazing. The vegetation on the peaty gleyed soils is associated elsewhere with drier soils, formerly extensive on the Beacons, and is preserved despite a changing edaphic environment. Some potentially nutritious pastures on the north face are too exposed to be grazed by sheep during winter, but Vaccinium pastures on some lower slopes supply useful winter protein.
GRASSLAND SYSTEMS*
Authors: Holmes W. , Allanson G.
Published: April 2006

Reference is made to the contrast between actual and potential yields from grassland, to the main factors affecting the development of effective grassland systems for dairy cows and to the technical developments which are now available. The unrealized potential for simplification and increased output from grazing systems is stressed.

The available information on the effect of mechanical grazing and storage feeding systems is reviewed and the practical advantages and problems of these systems summarized.

Simple calculations are made of the capital involved in large herd organization and the increases in herbage yield or efficiency of use needed to justify this additional expenditure. For large herds a relatively small increase (10%) in output per acre would justify the annual capital charge and feed cost for mechanical harvesting or tower silage; greater increases would be needed for grass drying (22%) or for tower silos in smaller (100‐cow) herds (16%). Other important but less tangible factors influencing the choice of system are referred to.

It is considered that unless herbage yields can be greatly increased by the use of mechanical grazing compared with normal grazing, the practical difficulties of this method outweigh its advantages. If tower silos allow more efficient conservation and easier feeding, they may be worthwhile, but the search should continue for cheaper alternatives. Only in very large‐scale enterprises can grass drying, solely to produce cattle feed, be justified, although this method offers the greatest potential.

In view of the complexities, it is suggested that computer models may help to resolve such problems and one such study is briefly described.
SALINITY EFFECTS ON ROOTS AND TOPS OF BERMUDA GRASS
Authors: Youngner V. B. , Lunt O. R.
Published: April 2006

Bermuda‐grass varieties, cut at weekly intervals, differed in salt tolerance when grown in 20 m. eq./l. Hoagland's Solution No. 1 plus 0, 80, 160, 240, and 320. m. eq./l. sodium and calcium chlorides. Weights of above‐ground parts decreased while root weight to top weight ratios increased with increased salinity. Highest root weights were obtained at the intermediate to high salt levels.

Explanations proposed for the root‐growth stimulation are: maintenance of a high photosynthetic rate despite retardation of top growth, reduced percentage defoliation resulting from top growth retardation or a differential response of tops and roots to growth hormones.
CHANGES IN THE BOTANICAL COMPOSITION OF A SOWN PASTURE ON THE CHALK IN KENT 1956–64
Authors: Wells T. C. E.
Published: April 2006

Changes in the cover of three grasses and two clovers sown in ploughed downland were measured annually for 8 years. Perennial ryegrass and cocksfoot were the most persistent of the sown species. Wild white clover increased in the first 3 years, but then decreased considerably, probably as a result of heavy grazing in the spring of 1960, and subsequently never recovered.

Invasion by weed species and the rate of reversion of sown leys on the chalk to permanent downland is discussed.
THE EFFECT OF TIME OF CUTTING ON THE MINERAL CONTENT OF A SINGLE–SPECIES SWARD
Authors: Thomas J. G.
Published: April 2006

Herbage samples are often taken for analysis in advisory problems concerning suspected mineral deficiencies in livestock. The adequacy of single samples is here assessed on two dissimilar sites. For this purpose S23 ryegrass was cut at similar stages of growth throughout the growing season and analyses carried out to determine the variation in the levels of calcium, phosphorus, potassium, sodium, magnesium, copper, cobalt and manganese resulting from different cutting dates. In many cases significant differences occurred between the levels of a particular element at different times during the year. These differences were large enough in some cases to influence advice based on a single result if taken in isolation.
THE DISTRIBUTION OF LEAF AREA AND LIGHT INTENSITY WITHIN WHEAT CROPS DIFFERING IN ROW DIRECTION, ROW SPACING AND RATE OF SOWING; A CONTRIBUTION TO THE STUDY OF UNDERSOWING PASTURE WITH CEREALS
Authors: Santhirasegaram K. , Black J. N.
Published: April 2006

The distribution of leaf area and light intensity within wheat crops differing in row direction, row spacing and rate of sowing is described. Regardless of the manner of planting, 75% of the total leaf area was found within a band 31/2 in. wide, centred on the centre of the row. Light penetration within crops spaced at 14 in. was greater than within those spaced at 7 in. Light penetration within rows running N.–S. was more uniform and higher, particularly around noon, than within rows running E.‐W. Within N.‐S. rows the position midway between rows received the highest amount of light, but light decreased on either side until it was least beneath the rows. Within E.‐W. rows at 14 in. spacing, maximum light was recorded at 101/2 in. on the southern side of a row, decreasing progressively as the row was approached.
AMMONIA AS A SOURCE OF NITROGEN FOR GRASS SWARDS
Authors: Cowltng D. W.
Published: April 2006

Aqueous ammonia was injected to a depth of 10 cm into small grass plots in late winter at rates equivalent to 200 and 400 kg N per ha. The effect on yield of DM, seasonal distribution of yield and uptake of N in the herbage was compared with that of single or split applications of ammonium nitrate. Two levels of supplementary irrigation were given in summer. The method of injection minimised damage to the sward and loss of ammonia by volatilization.

Aqueous ammonia and ammonium nitrate (single application) gave similar yields of dry matter, uptake of N and distribution of yield over the season. Ammonia was no more effective than ammonium nitrate under dry conditions. A single application in February of 200 kg N/ha as ammonium nitrate gave a greater total annual yield than the same quantity of N as ammonia or as a split dressing of the solid fertilizer. At 400 kg N/ha, split application gave the highest yields. The uptakes of N in the harvested grass was similar, in each irrigation treatment and at each level of N, for the three methods of applying N, The apparent recovery was low.

Aqueous ammonia, efficiently injected, was a satisfactory form of N for grass at the first cut, but it did not provide a continuing supply of N for crops harvested later in that season.
SOME EFFECTS OF SOIL‐WATER CONDITIONS AND SOIL TEMPERATURE ON THE ROOTS OF GRASSES AND CLOVER
Authors: Garwood E. A.
Published: April 2006

The effects of soil water conditions and soil temperatures on the growth of grass and clover roots and on the number of new adventitious roots were examined in the field and in glasshouse experiments.

Although significantly more new roots were produced when swards were irrigated during extremely dry periods, the effect was small, In general, irrigation appeared to have little effect on the seasonal pattern of production of new roots from the base of the plant.

High soil temperatures affected root growth. Branching of roots was increased by high temperatures, but the number of new roots formed at the base of the tillers was decreased, and the mean diameter of the roots was decreased. A multiple regression analysis of the number of new roots beneath a unit area of sward with soil‐water conditions and soil temperatures at the time of sampling gave a significant inverse relationship with soil temperature. No relationship could be demonstrated
THE PRODUCTION OF DRY MATTER BY SWARDS OF PERENNIAL RYEGRASS, DIFFERING IN AVERAGE AGE OF FOLIAGE
Authors: Anslow R. C.
Published: April 2006

Leaves of different ages were removed 7 times between June and October. Each defoliation was timed to match the appearance of successive leaves on each tiller. The removal of leaves at progressively younger stages reduced total production above ground, but the most severe treatment, the removal of all expanded leaves repeatedly, still produced about 75% as much as the least severely defoliated sward. Clipping with shears 3 times reduced yield as much as removing all expanded leaves 7 times. A crop allowed to grow untouched apparently produced more than any defoliated treatment, but this may have been an artefact.

The lower production following increasingly drastic defoliation was not associated with reduced concentrations of nitrogen or potassium in the foliage removed, or in the crop left behind. The total quantity of these elements recovered in the crop was greatest in those treatments where least dry matter was produced. Explanations for the results depend on the capacity of swards of predominantly young leaves to assimilate carbon more rapidly than those containing old and senescent tissue.
AN EVALUATION OF AN ELECTRONIC INSTRUMENT FOR PASTURE YIELD ESTIMATION
Authors: Back H. L.
Published: April 2006

A model of the electronic instrument described by Campbell et al. (3) was built at the Grassland Research Institute and was found to behave in a very similar way to their New Zealand model. A considerable amount of field work was undertaken with it in 1964 and this demonstrated that no general relationship of acceptable accuracy had yet been found; nor could it be sufficiently improved by the inclusion of the meteorological and botanical factors recorded. This forces one to a consideration of double‐sampling techniques, which appear worth while; they will be discussed in Part 2 of this paper.
THE EFFECT OF PHYSIOLOGICAL STATUS ON DIET SELECTION BY GRAZING EWES
Authors: McManus W. R. , Arnold G. W. , Ball Judith
Published: April 2006

The effect of the physiological status of grazing ewes on diet selection was studied, using ewes with oesophageal fistulae. The diets of dry ewes grazing Phalaris annual grasses and subterranean clover pastures, over a range of availabilities, were compared with those of ewes in various stages of pregnancy and lactation. There were no significant differences at any stage of reproduction in the botanical composition of the diets. However, small differences in diet digestibility, soluble carbohydrate and nitrogen content were found during pregnancy and lactation. These occurred at all levels of availability of pasture. The differences did not appear to have nutritional significance in the particular pasture ecosystems studied because levels of N, soluble carbohydrates and digestibility of the diet were such that selection for survival was unlikely to be necessary.

It is concluded that dry fistulated ewes can be used to obtain samples for assessing diet N and soluble carbohydrate contents for ewes in other physiological states. The use of in vitro digestibility tests of diets of dry ewes to assess diet digestibility for ewes in other physiological states may be subject to error.
PERFORMANCE AND VITAMIN A STATUS OF SHEEP GRAZING HIGH‐NITRATE PASTURES
Authors: O'Donovan P. B. , Conway A.
Published: April 2006

Nitrogen levels of 0,184 and 368 Ib (0,83.47 and 166.94 kg) were applied, as calcium ammonium nitrate, in six dressings throughout the grazing season to a perennial ryegrass/white clover sward. Herbage samples taken, periodically from each treatment and analysed nitrate for, indicated that the latter increased with increasing levels of applied nitrogen. Herbage nitrate levels were higher towards the end of the grazing season than at any other time. There was no consistent relationship between applied nitrogen and total plant nitrogen, although the latter tended to run parallel with applied nitrogen levels during the early part of the year.

Sheep performance was significantly increased with the first increment of 184lb (83.47 kg) of nitrogen; a second increment of 1841b resulted in a further, but non‐significant, increase. High‐nitrate pastures did not significantly reduce liver vitamin A storage in sheep. It is suggested that approximately 350 Ib (158.79 kg) of nitrogen, applied uniformly throughout the grazing season, results in pasture nitrate levels which have no adverse affect on sheep performance.
A HISTORY OF THE INTRODUCTION OF TIMOTHY AND COCKSFOOT INTO ALTERNATE HUSBANDRY IN BRITAIN. 1. THE YEAR 1763 AND ITS SIGNIFICANCE
Authors: Beddows A. R.
Published: April 2006

Timothy (Phleum pratense) and cocksfoot (Dactylis glomerata), although indigenous and commonly distributed, found no place in alternate husbandry in Britain until the end of the eighteenth century. Their value was then discovered as an indirect consequence of the search by the London Society of Arts for plants able to grow during the ‘dead season’ of the year. Letters on the subject were addressed by the society to Europe, Asia, North America and to people at home, but with no positive results. There was, however, in the New England provinces of America a developing enthusiasm at that time for timothy and, although not a winter grower, its merits became a matter for correspondence and discussion within the Society. A consequence was the arrival from America early in 1763 of various lots of seeds, but without any information as to sender(s) or the species. Both timothy and cocksfoot must have been received, for each were sown later that year at Walham Green, London, and the optimism and controversy regarding them led ultimately to a recognition of their worth and place in ley farming. The earliest sowing of American timothy in England occurred in 1743, but was without influence on agricultural thinking.

Reference is made to the introduction of European species into North America, and also to the Georgical Committee set up in 1664 by the Royal Society.
PRODUCTIVITY OF TROPICAL PASTURES
Authors: Blydenstein J. , Louis S. , Toledo J. , Camargo A.
Published: April 2006

A 50‐animal herd of dairy cows was pastured throughout one year on fertilized Pangola grass pastures in the humid tropical environment of Turrialba, Costa Rica. Information was collected on monthly grazing pressure, forage consumption and digestibility and milk production. The average number of animal units (375 kg) over the year was 2.57/ha. Total milk produced was 6014 kg/ha. Forage consumption varied from 1.81–3.60 kg DM per 100 kg liveweight, with two periods of low consumption coinciding with the flowering period of Pangola grass and with a drier season. Digestibility fluctuated from 50.3–65.7% and followed the same pattern. Calculations were made of the efficiency of DM conversion, which was around 12%, with two higher values for the periods of stress, interpreted as utilization of body reserves. Calculations of the nitrogen balance of Pangola pastures are also presented.
THE EFFECT OF SEED WEIGHT AND DEPTH OF SOWING ON THE EMERGENCE AND EARLY SEEDLING GROWTH OF PERENNIAL RYEGRASS (LOLIUM PERENNE)
Authors: Arnott R. A.
Published: April 2006

Seed of S24 perennial ryegrass of two weight ranges, 0.9–2.1 and 2.5–3.6 mg, were sown in soil at depths of 1.25, 2.5, 5.0 and 7.5 cm. Seedling growth was studied during the 3 weeks following germination.

Seeds of both weight ranges germinated equally well at soil depths down to 7.5 cm. However, the number of shoots that emerged was reduced as the sowing depth increased. At similar depths of sowing, seedlings from the heavy seed were heavier and developed more leaves and tillers than those from light seed. Deeper sowing reduced seedling weight and the rate of leaf‐ and tiller‐production. After emergence, the relative growth rates of the seedlings which grew from seed of both weight ranges were similar at those depths of sowing which permitted the highest proportion of emerged shoots to seeds sown. This indicates that the weight advantage gained by the seedlings that developed from heavy seed during their non‐photosynthetic stage of growth was maintained, and was not increased by a greater relative growth rate after photosynthesis began.

The implications of the findings are discussed in relation to plant breeding, commercial seed production and sward establishment.
PRODUCTIVITY OF TROPICAL PASTURES
Authors: Blydenstein J. , Louis S. , Toledo J. , Camargo A.
Published: April 2006

A 60‐cow dairy herd was pastured throughout one year on unfertilized Guineagrass pastures in the humid tropical environment of Turrialba, Costa Rica. During part of this time, the producing herd was followed by dry cows in the rotation. Information was collected on monthly grazing pressure, forage digestibility and consumption, and milk yields. The average number of animal units (375 kg) over the year amounted to 1.06/ha. Forage consumption varied from 2.27–3.45 kg DM/ 100 kg liveweight, and consisted of 75% Guinea grass in the mixed pasture. Digestibility varied from 47.9–65.0%. Low consumption and digestibility coincided with the short drier season. Efficiency of DM conversion was about 13% with one high and one low value, interpreted as use and accumulation, respectively, of body reserves during those periods. Calculations of the N balance in Guineagrass pastures are given.
THE POTENTIAL OF LOTUS spp. FOR HILL LAND IN WALES
Authors: Davies W. Ellis
Published: April 2006

Thirty‐four introductions of Lotus corniculatus and L. uliginosus, obtained from Europe, North America and New Zealand, were grown in plots with Aberystwyth S23 ryegrass at three centres in Wales (230–400 m a. s. 1.) to assess their potential as legumes for poor acid hill soils. The control white clover varieties were generally successful in these difficult conditions, whereas all the Lotus introductions were poor in two experiments and in the third experiment gave way to volunteer white clover by the third harvest year. These results indicate that none of the numerous Lotus varieties tested would be a useful addition to pasture seeds mixtures for hill lands in Wales.
THE USE OF MIXTURES OF GRANULAR DALAPON, BIRDSFOOT TREFOIL SEED AND FERTILIZER FOR ROUGHLAND PASTURE RENOVATION
Authors: Winch J. E. , Watkin E. M. , Anderson G. W. , Collins T. L.
Published: April 2006

Trials were conducted to determine the feasibility of combining granular dalapon, P fertilizer and birdsfoot trefoil seed in mixtures for renovating natural grass pastures in Ontario. The aim was to develop a ‘once‐over’ method to facilitate the renovation of pastures characterized by rough topography, rock outcrops or surface boulders.

Dalapon at 4 lb. a.i./ac (4.4 kg/ha) controlled the growth of Canada bluegrass (Poa compressa L.) and did not affect the germination and seedling growth of trefoil when applied simultaneously with the seed. Up to 100 lb/ac (112 kg/ha) P2O5 could be added to the mixture without detriment to trefoil establishment. The application of dalapon, P and seed in mixture by fixed‐wing aircraft, helicopter or ground equipment gave five‐to ten‐fold increases in pasture productivity and proved to be a practical method of pasture renovation.
THE GENERAL PATTERN IN SILAGE FERMENTATION IN TWO SUBTROPICAL GRASSES
Authors: Catchpoole V. R. , Williams W. T.
Published: April 2006

Three sets of previously‐published experiments have been re‐analysed by numerical methods intended for the elucidation of pattern in sequential data. The results suggest that for Setaria sphacelata cv. Nandi and Chloris gayana cv. Samford Rhodes the stable terminal silage to be expected under subtropical conditions is not the high lactic‐acid silage of temperate regions, but a silage with a relatively high proportion of acetic acid. Lactic‐acid silage is formed, but usually behaves as though in a transitional phase. However, silage made from mature Setaria can be maintained in the lactic‐acid phase by the addition of high percentages of sugar. The silage fermentation can sometimes be retarded, or deflected into an undesirable path for reasons that are not understood.

The above patterns suggest three hypotheses for more fundamental investigation. First, since acetic‐acid silage can be expected under most subtropical conditions, its properties require careful investigation. Secondly, relatively young Setaria may be regarded as a source of acetic‐acid silage, but the optimum amount of sugar to be added for ensiling more mature grass needs investigation. Thirdly there is an urgent need to investigate the causes of retardation of fermentation, and of its deflection into an undesirable path, because until these causes are understood, the outcome of ensilage will remain uncertain.
THE EFFECT OF FERTILIZER NITROGEN AND WHITE CLOVER ON HERBAGE PRODUCTION
Authors: Wolton K. Margaret , Brockman J. S.
Published: April 2006

The effect of a range of N rates on herbage production from grass/white‐clover and grass swards was investigated in two long‐term grazed experiments. The mixed sward yielded more than the grass swards over the range of fertilizer rates tested which were 0–120 lb N/ac (134.5 kg/ha), but the response of the mixed sward to fertilizer N was less than that of tbe grass sward. Tbis was due to the direct and indirect effect of clover, which was considerable with no fertilizer N but decreased witb increasing rates of application. However, clover was not completely suppressed by N at eitber site and contributed to berhage yields at all N rates.

Rate and time of N application and the amount of clover in tbe sward affected tbe seasonal distribution of DM yields. The mid‐season decline was less marked at bigb‐ tban at intermediate‐levels of N supply.
THE EFFECT OF NITROGENOUS FERTILIZER ON THE RATE OF GROWTH OF ITALIAN RYEGRASS
Authors: Wilman D.
Published: April 2006

In an experiment described earlier (13), the N content of Italian ryegrass in spring reached a high value one or two weeks after applying N and then fell quickly at first and then more slowly. After 10 weeks average N content (in DM) was 0.6% from an application of 25 lh N/ac (28 kg/ha), 0.9% from 75 lb N (84 kg/ha), and 12% from 125 lb N (140 kgJha). Nitrate‐N content fell more abruptly and tben remained fairly constant. Percentage nitrate–N (in DM) fell below 0.10% during the second week after an application of 25 lb NJac, during the third week after 75 lb N, and during the fifth week after recciriag 125 lb N. The yield of N increased during the first 5 or 6 weeks, remained fairly constant for 3–5 weeks, and then hegan to fall. During the ninth and tenth weeks, the crop lost an average of 9 lb N/ac per week (10 kg/ha) after an application of 75 Ib N/ac and 12 lb N/ac per week (13 kg/ha) after 125 Ib N.
THE USE OF CATTLE AND SHEEP FOR EVALUATING GRASS AND LEGUME SWARDS, A COMPARISON OF METHODS
Authors: Calder F. W.
Published: April 2006

A comparison was made of the effects of grazing with cattie and sheep separateiy hy two methods, continuous and rotationai on two forage mixtures. The two mixtures were timothy (Phleum pratense L.) with iadino white ciover (Trifolium repens L.); and brome grass (Bromus inermis Leyss) witii aifalfa (Medicago sativa L.). The rotationai system of grazing created different effects on sward composition from those caused hy the continuous grazing system. The legumes survived hetter under rotational than continuous grazing. Sheep, under both grazing systems, grazed more severeiy than cattie; they defoliated the ieaf portion of the plants and ieft more stem standing than did the cattle. Protein of the sward increased with the leaf portion, but in vitro digestibility was not altered as leaf to stem ratios changed. Although the gross effects of sheep and cattle were similar, there were differences in detail in the effect on these swards.
COMPARATIVE STUDIES OF PERENNIAL RYEGRASS. TIMOTHY AND MEADOW FESCUE.
Authors: Aider F. E.
Published: April 2006

Hays made, mainly in May, from pure swards of perennial ryegrass, timothy and meadow fescue were fed to 8‐month old steers in 1963 and to yearling steers in 1964. High‐quality hay was obtained, but no significant differences in growth rate were observed between calves fed on hays from the 3 species. In 1963, barley (1.5 kg DM/ head per day) was fed, in addition to the hays, to half the animals and resulted in a significant increase in live weight gain.

The productivity, in terms of liveweight gain/ unit area, of each species when managed for hay and‘zero grazing', or hay and grazing, was calculated. On this calculation perennial ryegrass was the most productive species.
THE EFFECT OF WINTER GRAZING BY SHEEP ON SPRING AND EARLY SUMMER PASTURE PRODUCTION
Authors: Frame J.
Published: April 2006

Studies were made in S.W. Scotland of the effect of winter grazing (October to March) by sheep on subsequent spring and early summer pasture production from a sward in its first harvest year and from a permanent pasture. Averaged over the two swards, DM yields in April, May and June were reduced by 38%, 8% and 5%, respectively, as a result of various times and frequencies of grazing, compared with no grazing. Reductions were greatest after grazings in the January to March period, especially grazings involving the month of March. In a trial in which fertilizer N was used to compensate for March grazing, 50 kg NJha raised DM yields in April to the level of those from no grazing, while only 15 kg NJha were needed to raise June yields to parity. Controlled winter grazing of sheep and the use of fertilizer N to restore production losses after early spring grazing are justified.
THE PRODUCTION OF CONTRASTING GENOTYPES OF PERENNIAL RYEGRASS (LOLIUM PERENNE L.) IN MONOCULTURES AND MIXED CULTURES OF VARYING COMPLEXITY
Authors: Rhodes I.
Published: April 2006

An experiment was set up to measure the production from donally propagated micro‐swards of four contrasting ryegrass genotypes, grown in monocultures and in all possible combinations of mixed cultures consisting of two, three and all four genotypes. Water and nutrients were supplied frequently in non‐limiting quantities and the swards were subjected to two cutting frequencies.

The yield ranking of the monocultures and mixed cultures diifered at the two cutting frequencies. Under infrequent cutting, though not under frequent cutting, two mixtures, each containing two genotypes, were more productive than their highest yielding components in monoculture. The physiological basis of this apparent synergy is hriefly discussed and it is suggested that the increased yield may he due to more efficient light utilization hy the mixtures. In general, yields of other mixtures, including those consisting of 3 or 4 genotypes were intermediate between the highest and lowest yielding components in monoculture.

The agronomic and plant‐breeding implications of the results are discussed.
HARVESTING TETRAPLOID RYEGRASS FOR SEED
Authors: Roberts H. M.
Published: April 2006

Sequential harvests of two tetraploid ryegrasses have shown that the commercially critical level of 90% germination was attained early in the ripening process. For the greater part of the maturation period the moisture level was maintained at 60% as in diploid grasses, but the rate of moisture loss during the latter part of ripening proved to be slower than in diploids. The large seeds are more susceptible to mecbanical damage at harvest and therefore require lower drum speed.
THE USE OF MEGACHILE ROTUNDATA F. AS A POLLINATOR OF LUCERNE IN GLASSHOUSES
Authors: Atjbury R. G. , Rogers H. H.
Published: April 2006

Alfalfa leaf‐cutter (Megachile rotundata F.) bees were used to pollinate lucerne plants in glasshouse compartments. This method was particularly useful in a plant–breeding programme where rapid multiplication was required.

Apparatus is described and some results are presented.
THE INFLUENCE OF SAMPLE SIZE AND NUMBER ON THE PRECISION OF ESTIMATES OF HERBAGE PRODUCTION AND CONSUMPTION IN TWO GRAZING EXPERIMENTS
Authors: Waddington J. , Cooke D. A.
Published: April 2006

Estimates of forage production and consumption were made, using dry‐weight differences between samples from protected and grazed areas. Two sizes of cage for protecting areas from grazing were compared in four forages: brome grass (Bromus inermis Leyss.)/Iucerne (Medicago sativa L.); crested wbeatgrass (Agropyron crista‐tum L.)/lucerne; intermediate wbeatgrass (A. intermedium (Host.) Beauv.)/Iucerne; and Russian wild‐rye (Elymus junceus Fisch.).

Production, over a three‐year period, ranged from 1985 to 6286 kg/ha when estimated from 0.84 m2 cages. Consumption ranged from 1584 to 5878 kg/ha. Yield estimates wben using 2.51 m2 cages averaged 8% less than estimates from 0.84 m2 cages.

The number of caged sites needed in each plot to estimate a 95% confidence interval for annual production were 14 for four replicates, and over 30 for fewer replicates. Requirements for consumption estimates were similar. To estimate production within a 90% confidence interval 19, 10 and 4 caged sites were required from two, three, and four replicates, respectively. Consumption estimates within tbis confidence interval required 22, 10, and 5 samples from two, tbree, and four replicates, respectively.

Caging requirements were tbe same for all combinations of plot size and forage species. Large cages increased precision sligbtly wben used on Russian wild‐rye, probably because the forage was in rows 0.91 m apart.
THE EFFECT OF SUPPLEMENTARY BARLEY UPON GROWTH AND EFFICIENCY OF FOOD CONVERSION IN CALVES KEPT AT HIGH GRAZING INTENSITY
Authors: Hodgson J. , Tayler J. C.
Published: April 2006

Three groups of Hereford × Friesian steer calves, bom in early January 1969, were strip‐grazed on eqoal areas of a sward of S321 perennial ryegrass from May to September inclusive, and received kibbled barley at the rate of nil, 3/4% or 1 1/2% of liveweight per day. Adjustments were made to the number of animals per group in order to maintain the same high grazing intensity (defined as 8 cm stubble height in grazed areas) on all treatments. The animals receiving supplementary barley gained weight at a rate 17–19% higher than the controls, but there was no significant difference in growth rate between the high and low levels of supplementation. The effficiency of conversion of barley was only 5–12 kg per animal liveweight gain/100 kg barley OM.

The high level of supplementation resulted in an increase in stocking rate of 36 % over that of the control group, and an increase in liveweight gain per unit area of land grazed of 63%. The additional liveweight gain due to supplements, expressed per unit area of land grazed, was relatively constant at 21–24 kg liveweight gain/ 100 kg barley OM consumed.
THE ELECTRONIC MEASUREMENT OF SMALL HERBAGE YIELDS USING A HIGH SENSITIVITY CAPACITANCE METER
Authors: Lovett J. V. , Burchi G. J.
Published: April 2006

The capacitance meters available in the past for estimating herbage yields have lacked sensitivity at the extremes of their range of measurement. The preliminary evaluation of a highly sensitive capacitance meter described here indicates that accurate measurement is possible in the range 0.1100 kg DM/ha. The implications of this development for the measurement of herbage of low availability are discussed.
REPEATABILITY OF A TWO‐STAGE IN VITRO SYSTEM OF DIGESTIBILITY MEASUREMENT
Authors: Brundage A. L.
Published: April 2006

Five substrates (high‐quality brome grass, low‐quality brome grass, lucerne pellets, lucerne cubes, and barley straw) were analyzed for DM disappearance in a two‐stage in vitro system in nine consecutive runs. Samples for each run were inoculated in duplicate with four independent collections of rumen fluid from the same mature, non‐lactating Holstein cow. Data repeatability was excellent for the two lucerne substrates, good for high‐quality brome grass, and poor for low‐quality brome grass and barley straw.
THE AGRONOMIC EVALUATION OF SYN 1 TALL FESCUE IN THE WEST OF SCOTLAND
Authors: Frame J.
Published: April 2006

The agronomic value of Syn 1 tall fescue, a synthetic variety derived from North African parent material, was determined in three experiments. Herbage yield, sward purity and digestibility were measured under cutting treatments for incremental sward growth during autumn/winter, and for sward regrowths during autumn/winter, spring and a complete season. Similar data were obtained for sward regrowths during autumn/winter and spring under defoliation by grazing. Syn 1 was compared with several of the north‐temperate region tall fescues, e.g. S170, Rozelle and Manade, also with S143 cocksfoot

Syn 1 showed yield superiority in autumn/early winter when there were comparable populations of tall fescue. Under cutting management, Syn 1 swards thinned out rapidly because of lack of winter‐hardiness and yields were depressed in the second season; the effects were worst under the winter foggage‐type management. Under grazing, with probably less severe defoliation, Syn 1 swards maintained yields for an additional season, but thereafter failed to persist Syn 1 swards had low spring‐ and annual‐yields.

The yield advantage of Syn 1 in autumn/early winter was not sufficient to be of great agricultural value and with its shortcomings in winter‐hardiness and annual yield, it was considered unsuitable for West of Scotiand conditions. The main value of plant material such as Syn 1 may lie in ccmferring autumn/winter growth potential to winter‐hardy north‐temperate tall fescues in a breeding programme.
STUDIES IN RESPONSE TO NITROGEN
Authors: Hunt I. V.
Published: April 2006

Regression equations have been calculated for the primary growth of a ryegrass sward as FM (fresh matter), DM, DOM and for uptake of N, K, P, Ca, Na and Mg after application of 59,118 or 177 kg fertilizer N/ha on 16 Apr. These have been used to predict changes in response with time, the responses in terms of time, the dates when specific yields of DM are attained, the different characteristics of herbages at specified yields of DM and the effects of changing harvesting interval on annual DM yield and uptake of minerals.

DM and DOM show significant responses to 118 kg N/ha but no response to the next increment throughout the 57‐day growth period. All other attrihutes, including FM, showed responses to 177 kg N/ha.

Calculated response as days gained suggest that for short‐interval grazing systems the use of even 118 kg N/ha is questionable.

The reduction in annual DM production and the increase in N uptake when growth intervals are shortened are related to the form of their growth curves.
INFLUENCE OF DRYING AND STORAGE CONDITIONS ON NONSTRUCTURAL CARBOHYDRATE ANALYSIS OF HERBAGE TISSUE—A REVIEW
Authors: Smith Dale
Published: April 2006

No one method of drying can be relied upon for all plant species, plant parts, or form (e.g., fresh v. ensiled herbage). Least changes in nonstructural carbohydrates appear to occur when fresh tissue is immersed in boiling alcohol. Freeze‐drying provides results more similar to fresh tissue than heat‐drying. Heat‐drying at high temperatures (above 80°C) can cause thermo‐cbemical degradation, while slow drying at low temperatures (below 50°C) allows time for DM losses by respiration and enzymatic conversions. The most acceptable heat‐drying results have been obtained by drying for a short time at a high temperature (i.e. 100°C) and thereafter at a moderate temperature (i.e. 70°C).

Changes in nonstructural carbohydrate concentrations occur during the storage of either freeze‐ or heat‐dried tissues. Thus, analyses should be conducted as soon as possible after tissue sampling. The least changes occur during storage in alcohol, following killing of the tissue in boiling alcohol.
THE EFFECTS OF DEFOLIATION ON EMERGENT ANNUAL GRASS SWARDS UNDER SIMULATED GRAZING
Authors: Greenwood E. A. N. , Titmanis Z. V. , Campbell N. A.
Published: April 2006

For three weeks after emergence, micro‐swards of Lolium rigidum were defoliated to a height and at a frequency which represented a range of set stocking rates of less than, similar to, and more than 7–8 sheep/ha as based on the results of Greenwood and Arnold (6) and referred to as D1, D2 and D3 respectively. The effects of these defoliation regimes on the growth and development of emergent swards were evaluated according to their effect on increments of DM from plant parts, rate of appearance of leaves and tillers, concentration of soluble carbohydrates, and on the uptake and concentration of inorganic nutrients.

Defoliation began five days after emergence, when the dry weight of the shoot was 3g/m2. After 20 days of treatment, 6±7 g/m2 of DM had been removed from D1, 5±5 g/m2 from D2 and 51 g/m2 from D3; and the dry weight of shoot remaining was 13, 7 and 4±5 g/m2 on D1, D2 and D3 respectively. The effect of defoliation on dry weight of plant parts increased in severity in the order leaf 1, stem+sheaths, leaf 2, roots, leaf 3, tiller 1, tiller 2, leaf 4. Average relative growth rate of the sward was reduced from 17% per day on D1 to 13% per day on D3. There was no necrosis of root tissue. Emergence of the later leaves and of the tillers was retarded by up to three days by more frequent defoliation. Alcohol‐soluble carbohydrates in the root fell from over 6% to about 1±5% on all treatments. Uptake of N. P and K was limited by increasing intensity of defoliation and because concentrations of those elements were not greatly affected, the limitation could be ascribed mainly to the effects of defoliation on plant size.

The plausibility of the technique for the experimental simulation of grazing of emergent annual grass swards in Western Australia is discussed. It is concluded that for set‐stocking rates of less than about 12 sheep/ha, grazing, while reducing DM production just after emergence, is unlikely to produce severe physiological stresses in the sward.
EFFECTS OF COW SLURRY ON HERBAGE PRODUCTION, INTAKE BY CATTLE AND GRAZING BEHAVIOUR
Authors: Pain B. F. , Leaver J. D. , Broom D.M.
Published: April 2006

Grassland plots were dressed with different amounts of cow slurry in January or March and grazed by dairy heifers at intervals from late April to August. In the first experiment slurry was applied at levels up to 56 tonnes/ha (22±4 tons/ac) in March. Total herbage DM production was directly proportional to the amount of slurry applied. There was no effect of treatment on percentage herbage utilization. In the second experiment slurry was applied at levels up to 100 t/ha (40 tons/ac) in January or in March. There was no significant effect of time or level of slurry application on herbage production or on animal intake, but the behaviour of the heifers was modified during the first eight weeks after plots had been dressed with 75 or 100 t/ha (30 or 40 tons/ac).
A NOTE ON THE INTAKE OF LACTATING EWES AT PASTURE
Authors: Young N. E. , Newton J. E.
Published: April 2006

The grass intake of three breeds of ewe was measured in the 5th–7th week (Period 1) and the 9th–11th week (Period 2) of lactation. The breeds of ewe were Finnish Landrace × Scottish Halfbred (FH), Finnish Landrace × Scottish Blackface (FB) and Thornber Colburn Colbred × Scottish Blackface (TC2). The immature FH ewes had a lower intake of digestible OM (26±1g/kg LW per day) than the mature FB (32±2g/kg LW per day) and TC2 ewes (33±5g/kg LW per day) in Period 1, but there were no difference between the breeds in Period 2. The intakes in Period 2 were significantly lower than those in Period 1.
AN INTEGRATING WATTMETER FOR MEASURING THE ENERGY USED TO GRIND PASTURE SAMPLES
Authors: Minson D. J. , Cowper J. L.
Published: April 2006

An integrating wattmeter for measuring the electrical energy used by a laboratory grinder during fixed periods of 60 or 90 seconds is described. The energy required to grind small forage samples was determined as the difference in energy recorded in separate periods when the grinder was either idling or grinding. the conversion of current used by the grinder to recorded output was linear over the range experienced when grinding forage samples.
THE EFFECT OF PESTICIDES ON THE YIELD AND BOTANICAL COMPOSITION OF A NEWLY‐SOWN RYEGRASS LEY AND OF AN OLD MIXED PASTURE
Authors: Henderson I. F. , Clements R. O.
Published: April 2006

Newly‐sown S24 perennial ryegrass at Hurley and old established ryegrass‐dominant mixed pasture at Rothamsted were treated with several pesticides, singly and in combination, over the period 1969–73. Yields were either unaffected or increased by up to 30% in any one year, depending on the treatment, the newly‐sown sward giving the more consistent response from year to year.
THE EFFECT OF SHOOLY LARVAE (DIPTERA) ON GRASS YIELD
Authors: Mowat D. J.
Published: April 2006

Elimination of shooly larvae increased grass yields daring the September feeding period. Increases were usually less than 10% bat in one case, where growth was abnormally slow, die increase was over 30% and in another, where the larval population was atypically dense, it was almost 60%. The effects of damage were not cumulative daring the feeding period; and at the end of this period insecticidreated plots sometimes gave lower yields than untreated plots. Fertilizer increases had a much greater effect on yield than did control of larvae and, where N was applied at 75 kg/ha (67 lb/ac) in spring, the additional effect of larval control was usually negligible. It is suggested that shoot‐fly damage may be more serious in other localities.

When turf containing shoot‐fly larvae was ploughed, Oscinella spp. re‐established themselves more successfully than others in seedling ryegrass bat did not damage the new sward appreciably.
A LINEAR PROGRAMMING MODEL OF A HIGH‐TEMPERATURE GRASS‐DRYING ENTERPRISE
Authors: Audsley E.
Published: April 2006

A linear programming model of a high‐temperature grass‐drying enterprise is described. From information about seasonal crop response, area of crop available and management constraints, the model determines the harvesting schedules which give greatest returns, less costs, from the enterprise over the season. This information can be used to examine the effects of long‐term strategic decisions or to evaluate economically data on new crops from field experiments. For example, assuming a fixed cost of λ70,000/year for a high‐temperature grass‐drying installation and what is considered to be reliable input data for 1972, the returns less costs for optimum harvest schedules from different areas or crop varieties are:

Corp area

Surplus

Grass ac (ha)
Lucerne ac (ha)
Return, £
Less costs £/ac(£/ha)
crop ac (ha)

800(324)
0(0)
42,849
536(132.3)
0(0)

1000(405)
0(0)
60,286
603(1489)
205(83)

600(243)
200(81)
46,731
58.4(1442)
0(0)

800(324)
200(81)
65.661
65.7(1621)
109(44)

The model can also provide information con cerning tbe limitations imposed by equipment stage of tbe process and management re straints sucb as limitations on overtime and shut downs for holidays or maintenance.
SEED PRODUCTION STUDIES ON PERENNIAL RYEGRASS, TIMOTHY AND PRAIRIE GRASS
Authors: Hill M. J. , Watkin B. R.
Published: April 2006

This paper considers the sequence of seed development by measurement and observation of ehanges in seed moisture content, weight, colour, endosperm consistency, germination capacity and yield in perennial ryegrass Grasslands Ruanui, timothy Grasslands Kahu and a New Zealand strain of prairie grass (Bromus unioloides).

Seed moisture content was high (60–70%) after anthesis and declined at different rates, depending on the species and the weather. Maximum seed dry weight (maturity) was reached approximately 30 days after peak anthesis in all species and was influenced by N application and grazing. Colour changes in the seedhead and endosperm solidification proved unsatisfactory as measures of maturity. Endosperm solidification was reached 4, 11 and 12 days before maximum seed dry weight in ryegrass, timothy and prairie grass, respectively.

Seeds removed from the plant as little as 7, 10 and 4 days after anthesis in ryegrass, timothy, and prairie grass, respectively, germinated, provided that dormancy was broken; but they did not retain viability after 3 months storage. Maximum viability of ryegrass, timothy and prairie grass seed tested immediately after harvest occurred 30, 38 and 16 days after anthesis, compared with 17, 35 and 12 days, respeetively, when germination testing was delayed for 3 months.

In ryegrass, grazing caused a significant increase in seed yield in the second year while N application alone did not significantly increase yield. In timothy, grazing and to a lesser extent N, were both detrimental to seed yield in the second year. Highest yields were obtained in treatments not receiving either grazing or N. In prairie grass, grazing depressed and N application increased yields in both years. In all species similar or increased yield could be obtained by mowing the crop at, or slightly prior to, seed maturity and allowing seed development and ripening to continue on the cut straw for up to 10 days. Using this technique higher seed yields were obtained in ryegrass and timothy than when seed was direct‐harvested. In prairie grass similar yields were obtained whether the erop was direct‐harvested or threshed following drying in the swath for 10 days.

The use of ‘drying curves’ for the prediction of correct cutting time of seed crops is suggested for ryegrass, timothy and prairie grass.