bluuebunny/crossref_metadata_2025 huggingface dataset:
THE RANGE—NATURAL PLANT COMMUNITIES OR MODIFIED ECOSYSTEMS?*
Authors: Love R. Merton
Published: April 2006

Range research and its application in the United States have been primarily in the area of ecology. The guiding principle developed is that the natural plant communities (the climax vegetation) provide the best guides to forage production potential.

A careful study of man's history from the Ice Ages to the present reveals the fact that man has progressed by modifying his environment. In fact, the ability to do so is one of the significant differences between man and other animals. During the last 10,000 years man has been in turn a collector and hunter, a cultivator and domesticator, and finally an industrial agriculturist. The transition has been a slow, laborious process.

The mixed‐oak forests of the Mediterranean and Europe were cleared by felling and burning the trees and cultivating the cleared ground by crude flint hoes. In his migrations man learned of differences in soils and adaptations of cultivated plants. He learned to work with nature, but he also learned how to overcome some of nature's limitations.

Agriculture, then, is man's attempts to overcome nature's limitations so that a desired crop can be grown and harvested. By this modification of the environment the crop supersedes the pattern of natural vegetation. There is no intrinsic difference between range and intensive agriculture, since both involve factors inherent in climate, soil, plants and harvesting.

Ecologists working in the field of range management must be willing to accept ideas and principles that have put more science in the “science and art” of farming, if the “science and art” of range management is to progress suffiientiy to make possible the realization of the vast potential of our ranges and wild lands.
THE EFFECT OF URINE AND ITS COMPONENTS ON THE BOTANICAL COMPOSITION AND PRODUCTION OF A GRASS/CLOVER SWARD
Authors: Mundy E. J.
Published: April 2006

A study was made of the effect of sheep urine and some of its components on herbage production. The return of urine to the sward increased production from the grass species; the clover content of the sward was reduced.

The application of nitrogen or potassium fertilizer equivalent to the normal return of nitrogen and potassium in urine increased production, but not as much as urine. The return of nitrogen and potassium fertilizer together increased production and altered botanical composition in much the same way as did urine.

On a grass‐dominant urine‐treated sward the application of nitrogen fertilizer increased the “efficiency” of urine.

The effect of urine on a grass/clover sward was almost entirely due to its nitrogen and potassium content. The water and indole acetic acid content of urine had no effect on pasture production or composition.
THE YIELD AND UPTAKE OF PHOSPHORUS BY GRASSES AND CLOVERS
Authors: Jenkins W. Lloyd
Published: April 2006

When perennial ryegrass and wild white clover are grown in a phosphorus‐deficient soil, there is a difference in the extent to which they use the added phosphorus, especially when the phosphorus supply (potential) is small. In these circumstances the clover makes the better use of the phosphorus. The similarity of the Larsen values obtained with these two species, however, indicates that this must be largely due to the species absorbing the phosphorus at different rates, and not to any interspecific difference in ability to utilize the supply. Both perennial ryegrass and cocksfoot gave higher L values for the hay than for the pasture variety, indicating that slowly‐exchangeable phosphorus might be more accessible to the former than the latter. Perennial ryegrass, cocksfoot, timothy, wild white clover and red clover showed minimum values for L at varying times after sowing which were characteristic of the species. This is explained in terms of the isotopic exchange reactions taking place.
DISTRIBUTION OF COUMARIN AND RELATED COMPOUNDS DURING LEAF GROWTH AND DEVELOPMENT IN ANTHOXANTHUM SPECIES
Authors: Davies E. G. , Ashton W. M. , Borrill M.
Published: April 2006

A study has been made of the relationship between the content of coumarin and its related compounds in the leaves of Anthoxanthum species. In the two species A. puelii and A. amarum, which headed without low‐temperature or short‐day induction, successive mature leaves on the main shoot were studied: they showed a general increase in the content of coumarin and related compounds up to the flag leaf which had a maximum value.

In A. odoratum, which was non‐heading when grown under the same experimental conditions, the distribution of coumarin and related compounds was examined during the life of individual leaves from emergence to senescence. Each leaf showed a similar basic pattern: a peak value for coumarin occurred at maturity, which coincided with an initial peak value for related compounds. With senescence the coumarin value in each leaf fell, but the related compounds, after an initial fall, now increased in concentration and attained a maximum at senescence.
EXPERIENCE WITH HIGH AMOUNTS OF NITROGEN ON GRASSLAND AT NITROGEN EXPERIMENTAL FARMS IN THE NETHERLANDS
Authors: v. d. Molen Ir. H.
Published: April 2006

In the Netherlands interest in fertilizing permanent grassland with nitrogen started about 1930. Since then many field experiments have been carried out on the effects of this treatment on grass production, and a short survey is given of the most important results up to c. 1940.

The effect of nitrogen fertilization is however not restricted to the production of grass. Many other factors in farm management are affected by it, e.g. stocking rate, cattle feeding, hay‐ and silage‐making, labour efficiency, etc., and experiments on a farm scale were necessary. These experiments started in the late thirties and were resumed after the war, on the so‐called nitrogen experimental farms. In this project co‐operation between the Department of Agriculture and the nitrogen industries in the Netherlands was established. The aim was to study the influence of nitrogen at a level of about 200 kg N/ha. From these farms data were collected on fertilization, production of grassland, botanical composition, cattle feeding, animal production, animal health and financial results. Results are given for six farms, which took part in the experiment for at least 7 years.

The following conclusions were reached:

The quantity and the quality of grassland production did not suffer from the application of high amounts of nitrogen, and there was no evidence of decreasing N‐effect with time.

Animal production was increased, due to a higher stocking rate as a result of the increased grass production, and production per animal was maintained at a very high level.

Animal health on the experimental farms compared favourably with the country average, though there were some difficulties. On highly intensive farms, special attention should be paid to the supply of energy, copper and magnesium.

The financial results of the experimental farms are in general much better than those of comparable farms using less nitrogen. An important factor is higher labour efficiency due to the increased stocking rate.
COMPETITION BETWEEN PERENNIAL RYEGRASS AND MEADOW FESCUE UNDER FIELD‐PLOT CONDITIONS
Authors: Crocker R. L. , Martin P. M.
Published: April 2006

Perennial ryegrass and meadow fescue were grown alone and in association in field plots, to gain an idea of the nature and importance of the competitive interactions between them, and their relative contributions to the yield of the newly‐established sward.

Experiments over 10 weeks and 9 months both showed that the contribution by fescue to the overall dry‐matter yield was severely restricted by perennial ryegrass. There were no deaths of fescue plants during the experimental period (which included an overwintered treatment). The depression in yield was rather a result of a marked decrease in size and weight of the individual plants, brought about by competition for light and nutrients from the faster‐growing ryegrass.
COMPARATIVE PRODUCTIVITY OF HERBAGE VARIETIES ON UPLAND PEAT
Authors: Hunt I. V.
Published: April 2006

The productivity and persistence of 27 varieties of herbage plants were compared, following sowing on a blanket peat after ploughing. Yields were estimated from 3–5 cuts per year for 5 growing seasons. The top yields in each year ranged from 2510 lb/ac. in the 5th year when no nitrogenous fertilizer was applied up to 4700 lb/ac. in the 3rd year when given 174 lb N/ac. Such levels are slightly less than half the level expected on lowland, but livestock output on hill land is far lower than on lowland. Varietal differences were significant, with red fescues, especially S59 smooth‐stalked meadow grass, S170 tall fescue, S143 cocksfoot, Yorkshire fog and S53 meadow fescue giving top yields and persistence. Aberystwyth varieties were in all cases superior to other varieties. S50 timothy and S23 perennial ryegrass were persistent but production was low. The conclusions are compared with those of other investigators.
THE NUTRITIVE VALUE AND AGRONOMIC ASPECTS OF SOME FODDERS IN NORTHERN NIGERIA
Authors: Miller T. B. , Rains A. Blair , Thorpe R. J.
Published: April 2006

Digestibility data are presented on the following; Andropogon gayanus hay and bush foggage, Arachis hypogoea (groundnut) haulms, Glycine max (soya‐bean) hay. Sorghum vulgare (sorghum) leaves and hay, Stizolobium sp. (velvet bean) hay, Vigna sinensis (cowpea) hay and haulms, and S. vnlgare/Stizolobium sp. mixture. The results are discussed from the agronomic aspect.
INFLUENCE OF PLANT EXTRACTS ON GERMINATION AND GROWTH OF EIGHT FORAGE SPECIES*
Authors: GRANT E. A. , Sallans W. G.
Published: April 2006

Seeds of four legumes and four grasses were germinated in the presence of aqueous extracts of the same species, using distilled water as a check. Measurements were taken to determine the effect of the extracts on germination, root growth and shoot growth. Based on the number of significant reactions to the extracts, the species may be classified in the following order of decreasing inhibition: alfalfa, birdsfoot trefoil, Ladino clover, red clover, reed canary grass, brome grass, timothy and orchard grass. Conversely, alfalfa and timothy were the species least affected by the extracts while reed canary grass was the most susceptible. Other species were in an intermediate range. With the exception of alfalfa, extracts of aerial portions of the plants had greater inhibitory effects than root extracts.
THE GROWTH OF LAMBS AT PASTURE
Authors: Large R. V. , Spedding C. R. W.
Published: April 2006

The two years' experiments described compared the growth of suckling lambs on ‘long’ and ‘short’ ryegrass swards. The animals were carried at a moderate stocking rate. Differences in sward height were established before grazing began and were maintained throughout each season. There were no significant differences in lamb growth between treatments. The structures of the swards are discussed in relation to the results, and the possible effect of differences in parasitic infestation on ‘long’ and ‘short’ swards is considered.
THE DIGESTIBILITY OF THE LEAVES AND STEMS OF PERENNIAL RYEGRASS, COCKSFOOT, TIMOTHY, TALL FESCUE, LUCERNE AND SAINFOIN, AS MEASURED BY AN IN VITRO PROCEDURE
Authors: Terry R. A. , Tilley J. M. A.
Published: April 2006

Determinations of the in vitro digestibilities of leaf‐blade, leaf‐sheath and stem fractions of the grasses cocksfoot, perennial ryegrass, timothy and tall fescue and of the leaves and stems of lucerne and sainfoin have shown that all parts of the plant have a high digestibility at early stages of growth. With increasing maturity, however, the digestibility of the stem falls off at a much faster rate than that of the leaf; in grasses, leaf‐sheath digestibility declines at an intermediate rate. The decline of digestibility is associated with a reduction in the content of water‐soluble and protein constituents in the plant, and with a reduction in the digestibility of fibre. This may provide a biochemical basis for the selection of forage plants of high digestibility in plant‐breeding studies.
THE OUTPUT OF SWARDS ON COMMERCIAL FARMS IN RELATION TO FERTILIZER AND OTHER MANAGEMENT FACTORS
Authors: Baker R. D. , Baker H. K.
Published: April 2006

Survey data collected during a grassland‐recording investigation showed a strong positive correlation between nitrogen input and the output of utilized starch equivalent per acre. At the levels of output covered, sward type was not very important in relation to total yield. Herbage species were important for other reasons and the choice of seeds mixtures should be determined by factors such as earliness and lateness of growth and resistance to disease and drought. The survey showed that well‐managed ley and permanent pasture are both capable of producing at a high level. A disturbing feature of the results was the low production of most spring resowings, primarily as a result of poor management.Althoughthe records were obtained from an above‐average group of farms, the results have general application. Potential responses to fertilizers may be even greater on less intensive farms, especially with regard to phosphate and potash. However, the level of production of a field will always depend finally on the level of management exercised by the farmer himself.
A COMPARISON OF THE REACTION OF DIFFERENT GRASS SPECIES TO FERTILIZER NITROGEN AND TO GROWTH IN ASSOCIATION WITH WHITE CLOVER
Authors: Cowling D. W. , Lockyer D. R.
Published: April 2006

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.
SOME FACTORS AFFECTING EARTHWORM POPULATIONS UNDER PASTURE
Authors: Watkin B. R. , Wheeler J. L.
Published: April 2006

The results of experiments undertaken in England and New Zealand are reported. Under highly productive pasture a significant correlation was found between pasture production and earthworm numbers and weights. This relationship was not evident until the pastures were more than 3 years old. On pastures of similar total dry‐matter production there was a significant correlation between yield of clover and numbers and weights of earthworms. The return of dung by the grazing animal increased earthworm numbers and weights, and the application of nitrogenous fertilizer had a similar but less marked effect. The earthworm population was not demonstrably related to the macro‐organic‐maller content of the pastures. The grazing of grass‐clover pastures was not essential for an increase in earthworm populations to occur.

Allolohophora species (mainly A. caliginosa) were dominant under pure grass swards, whereas Lumhricus species (mainly L. rubellus) were dominant under grass/clover swards.
FURTHER STUDIES ON SHEEP GRAZING IN THE NORTHERN PENNINES
Authors: Rawes M. , Welch D.
Published: April 2006

The grazing of 3 relatively productive grasslands (Festucaf Agrostis) by hill sheep was examined in relation to herbage consumption, grazing pressure, dung deposition and the number of sheep in the area. Herbage intake ranged from 400 Ib/ac/annum (dry weight) on the highest (2450 ft O. D.) and most exposed grassland to 800 Ib/ac/annum on a grassland (1700 ft O. D.) adjacent to extensive heather moorland on blanket bog. The highest pressure (5·5 sheep/ac) was also found on grassland surrounded by blanket bog (1 sheep/14 ac).
THE ROUTINE DETERMINATION OF IN VITRO DIGESTIBILITY OF ORGANIC MATTER IN FORAGES‐AN INVESTIGATION OF THE PROBLEMS ASSOCIATED WITH CONTINUOUS LARGE‐SCALE OPERATION
Authors: Alexander R. H. , McGowan Mary
Published: April 2006

A procedure and equipment which make possible a continuous output of 250 to 300 determinations of in vitro digestibility of organic matter per week are described.

The effect on in vitro digestibility values of removing rumen liquor from sheep at various times before and after feeding, mixing of rumen liquors from different sheep, and nitrogen supplementation of the inoculum are investigated. Results are given of a comparison of the effect of soil contamination on in vitro data when expressed as digestibility of dry matter and digestibility of organic matter. The levels of within and between‐batch errors are stated and the accuracy of prediction of feeding value is discussed.
COMPETITION BETWEEN WHEAT AND UNDERSOWN PASTURE IN THE YEAR OF SOWING AND THE EFFECT OF UNDERSOWING ON THE YIELD OF PASTURE IN THE FOLLOWING YEAR
Authors: Santhirasegaram K. , Black J. N.
Published: April 2006

Sowing pasture species with wheat caused a reduction in the growth and yield of the pasture species. This reduction was more severe with wheat drilled at 7 inch row spacing than at 14 in., and was least when the two crops were in alternate 7 in. rows. The reduction appeared to be due principally to the shade cast by the wheat. The pasture also reduced the growth and yield of wheat, but the effect of row spacing and position were opposite to and very much less marked than those of wheat on pasture. The yield of the pasture early in the following season was related to the seed yields in the year of establishment; later in the season, however, differences in yield among the various treatments disappeared.
SYSTEMATIC TESTING OF QUALITY IN GRASS VARIETIES
Authors: Dent J. W. , Aldrich D. T. A.
Published: April 2006

Methods of testing grass varieties are discussed and the efifects of differences in management and of nitrogen fertilizer on quality are shown. In a grazing‐management system with 9 cuts per season, cocksfoot was higher than perennial ryegrass in protein and fibre and lower in soluble‐carbohydrate content and in vitro dry‐matter digestibility throughout the season. All species showed the lowest value for digestibility in August.

Curves for digestibility in primary growth were plotted for 4 varieties of ryegrass for leaf and stem fractions. The tetraploid variety Reveille was slightly more digestible than S24 in leaf and stem throughout the period, while at ear emergence S23 was lower in digestibility in both fractions than S24.

There were significant differenees in composition and digestibility between experimental centres, but relative differences between varieties were consistent. The level of N fertilizer did not materially alter the comparison between varieties in quality data.
THE QUANTITY AND FREQUENCY OF REMOVAL OF HERBAGE FROM AN EMERGING ANNUAL GRASS SWARD BY SHEEP IN A SET‐STOCKED SYSTEM OF GRAZING
Authors: Greenwood E. A. N. , Arnold G. W.
Published: April 2006

A newly sown sward of Lolium rigidum was set‐stocked from one week after emergence onwards at 7.4 sheep/ha.

The proportion of dry matter removed from the sward by grazing each week fell from 20 to 1%/day over the first 7 weeks after emergence.

Time‐lapse stereo photography showed that in the immediate post‐emergence period sheep tended to graze the elongating, or incremental, component of dry matter rather than the fully expanded butts of previously defoliated mature leaves.

Frequency of defoliation decreased with time. 97% of plants were defoliated in the second week after emergence, but only 44% in the eighth week.
UPLAND GRASS PRODUCTION IN NORTH‐EAST SCOTLAND IN RELATION TO SOIL AND SITE CONDITIONS
Authors: Beavington F.
Published: April 2006

An experiment involving 24 grassland sites was carried out to measure the influence of a large number of variables on upland yields between 900 and 1450 ft above sea level in western Aberdeenshire. The grass was harvested in mid‐July and at the end of October 1966. Few factors were significant in the first harvest yields. In the second harvest yields, aspect and soil parent material were both significant at the 1% level, and available soil phosphate at the 5% level. Total yields (DM) for the growing season were correlated with parent material (2% level), with available soil P (1% level) and with the P and K content of the leaf (1% and 5% levels). Yields were also correlated with sward age (5% level) and sward condition (1% level). A number of variables were highly correlated with sward age and condition, including the leaf content (second harvest) of K, P and crude protein (0.1%, 1% and 1% levels).

The highest yield was 4700 kg/ha/year and the average yield 2585 kg/ha/year, but the results showed that the average could be substantially increased by good management, especially by P fertilizer. The results confirmed that there was no marked fall‐off in yields with increasing altitude (r=0.066, 0.194 and 0.112) and there appeared scope for reclamation on suitable sites at higher elevations.
THE USE OF THE IN VITRO TECHNIQUE IN THE DETERMINATION OF THE DIGESTIBILITY OF GRASS/LEGUME MIXTURES
Authors: McLeod M. N. , Minson D. J.
Published: April 2006

The in vitro dry‐matter digestibility was determined of two samples of Digitaria decumbens, one sample of Medicago sativa, and one sample of Trifolium repens and nine mixtures prepared from these samples.

When the results were compared with in vivo digestibilities the standard errors of the regressions for the three combinations of legume, grass and legume/grass mixtures were ±0.6, ±0.6 and ±1.5 percentage units, respectively.

It is considered that in vivo digestibility of mixtures of grasses and legumes can be estimated by the in vitro technique, provided that suitable grass and legume standards are included.
CARBON, NITROGEN, PHOSPHORUS AND SULPHUR IN HERBAGE PLANT ROOTS
Authors: Whitehead D. C.
Published: April 2006

C. N, P and S were determined in the roots of white‐ and red‐clover, lucerne, perennial ryegrass, cocksfoot and timothy, taken at intervals over a period of several months, and in roots of ryegrass receiving four levels of fertilizer N.

The results indicated that decomposition of The root material would result in The mineralization of N in substantial amounts from white clover, in smaller amounts from red clover and in negligible amounts from lucerne. The roots of grasses would tend to immobilize soil N, even when They bad received moderate applications of fertilizer N. The C:P ratios suggested that the legume roots would neither mineralize nor immobilize inorganic pbospbate but that the grass roots would induce immobilization. S was likely to be mineralized in appreciable amounts from roots of white– and red–clover, but not firom roots of lucerne or the grasses.
PREDICTING THE BEST TIME TO APPLY NITROGEN TO GRASSLAND IN SPRING
Authors: Jagtenberg W. D.
Published: April 2006

A great number of experiments with varying dates of N application to grassland showed that the most suitable time of applying spring N in tbe Netberlaods varies, as a result of weather conditions, from year to year from mid‐February to mid‐April. In such experiments the best time of spring N application, which needs to be known in advance, can only be determined after the grass bas been harvested and weighed. The results of these experiments supported the opinion that the best application date coincides with the banging of grass growth. However, at that time it was not possible clearly to define the begimiing of grass growth.

When in 1959 a measuring disc was put into use the beginning of grass growth could be precisely determined and it was then found that the beginning of grass growth was closely correlated to a certain accumulated temperature from 1 Jan. from which the date of the beginning of grass growth can be predicted. This date is the most suitable one for applying spring N to grassland.
EFFECT OF SOIL PARENT MATERIAL, ELEVATION, ASPECT AND FERTILIZER TREATMENT ON UPLAND GRASS YIELDS
Authors: Burnham C. P. , Court M. N. , Jones R. J. A. , Tinsley J.
Published: April 2006

Grass production was measured at 24 sites in the Strathdon area of West Aberdeenshire. The mean total yields of DM from two cuts taken from unfertilized plots in 1967 and from three cuts taken in 1968 were 3014 and 3864 kgJha, respectively. Yields from soils formed on basic parent material were 30–40% more than yields from soils formed on more acidic material; and well‐managed swards yielded over 40% more than poorly‐managed ones. Aspect did not affect yields significantly, nor did elevation within the range 260–440 m.

NItrochalk applied at the rate of 75 kg N/ha in 1968 increased the DM yield by an average of 35% but the efifect of 75 kg P2O5/ha, applied as triple superphosphate, was not significant at the 10% level. The benefits from N declined, wbereas those from P tended to increase, with elevation. There was no significant NP interaction overall, but tbe response from this treatment was better than from N alone on sites with acidic parent material.

In 1968, 46% of the total yield was obtained by the end of June and only 10% after the end of August. Whereas yield declined with elevation in May–June, it increased during July–August
THE EFFECT OF NITROGENOUS FERTILIZER ON THE RATE OF GROWTH OF ITALIAN RYEGRASS.
Authors: Wilman D.
Published: April 2006

Residual response to an initial application of nitrogen was measured in 3 years and was found to be quite large, e.g. a response of 8 Ib DM per extra Ib N at the first harvest, when applying 125 Ib N/ac (140 kg/ha) rather than‘75 Ib (84 kg/ha) and allowing 6 weeks' growth, was increased to 21 Ib DM when yield from residual cuts was taken into account. Response was large in relation to the amount of N estimated to have been left behind after the first harvest. Marginal recovery of N, already quite high at the first harvest, was increased to a little over 90% when yield from residual cuts was taken into account Recovery, however, was lower than this when 10 weeks' growth was allowed before the first harvest, and it seems that, in this case, some N may have been lost from the system. A supplementary experiment suggested that the residual effect of N on DM yield could be obscured to some extent by fresh applications of N.
ECONOMIC ASPECTS OF THE INCLUSION OF DRIED GRASS IN DAIRY‐COW RATIONS
Authors: Crabtree J. R.
Published: April 2006

A linear programming model was formulated to calculate a least‐cost ration for lactating dairy cows with respect to certain nutritional constraints. The model was used to derive the price at which dried forage of a stated digestihle crude protein content (DCP) and metabolizable energy content (ME) would just become included in a least‐cost feed. Marginal costs for DCP and ME of £0.057/ kg and £0.0096/Mcal, respectively, were calculated. These were found to be fairly Insensitive to changes in milk yield. Inclusion prices were slightly lower than current market prices.
INTERACTIONS OF GRAZING AND BURNING ON HEATHER MOORS
Authors: Grant Sheila A.
Published: April 2006

Standing crops on plots of 5‐ to 11‐year‐oId heather subjected to six different grazing regimes ranged from 2400–10,000 kg/ha. Stand development of heather was greatly influenced by grazing management.

Distribution of DM among the five fractions, flowers, current season's growth, older green material, wood and dead material, was significantly affected by both age and grazing regime and by the interaction of these two factors.

Annual DM production ranged from about 1000 to 2000 kg/ha and there was no evidence of any impairment in the productive capacity of the heather plant with the levels of utilization which resulted from the six grazing regimes used.

Factors involved in the evaluation of heather as a source of feed for ruminants are discussed briefly, as also are the problems of relating levels of utilization to grazing management.
A NOTE ON THE LIVEWEIGHT CHANGE OF SHEEP GRAZING AT THREE STOCKING RATES AND TWO LEVELS OF NITROGENOUS FERTILIZER
Authors: Scarisbrick D. H.
Published: April 2006

The liveweight changes of sheep grazing at 3 stocking rates and 2 levels of N fertilizer were recorded. The results are discussed in relation to the model proposed by Owen and Ridgman (1) for short–term periods of grazing.
THE EFFECTS OF CUTTING AND FERTILIZER TREATMENTS ON THE YIELD AND BOTANICAL COMPOSITION OF CHALK TURF
Authors: Smith C. J. , Elston J. , Bunting A. H.
Published: April 2006

Annual factorial applications of N and K fertilizers, with or without mowing, to Festuca rubra turf on a chalk rendzina at Swyncombe, Oxon, had large effects on yield and botanical composition over a period of 10 years. The yield of herbage was increased markedly hy N, and less by K, but the N × K interaction was significant. Mean yields of herbage DM for tbe 10‐year period were: no N or K, 730 kg/ha per year; N, 1967; K, 1013; N+K, 2794 kg/ha per year (651, 1755, 904 and 2492 lb/ac per year). N caused an increase in DM production by F. rubra; the NxK interaction was a result of increased growth of species other tban F. rubra.

Unmown plots became extremely matted, and undecomposed litter of F. rubra leaves and stems accumulated, especially if N, or N and K together, were given. F. rubra turf seems to he unusually stable, apparently because it forms a mat in which other more demanding species cannot establish themselves.
THE CATTLE DUNG PATCH
Authors: Macdlarmid B. N. , Watkin B. R.
Published: April 2006

The eifect of 1 ft‐diameter (0.30 m) dung patches on the yield and botanical composition of a dairy pasture was followed in two randomized‐block experiments. Experimental plots consisted of 3 concentric rings round each dung patch of diameter 2 ft (0.61 m), called R2; 3 ft (0.91 m), called R3; and 4 ft (1.22 m), called R4. They were sequentially harvested.

In the first experiment described there was a significant increase in the total yield of grass species, predominantly ryegrasses, around each dung patch. This increase was first evident in R2 but spread progressively outward and was still detectable in R4.

Plant material, particularly clover components, decayed rapidly beneath the dung patches. Leaving a dung patch on the pasture for 15 days kiUed 75% of the grass tillers and the rooted nodes of clover stolons; thus causing a significant reduction in pasture regrowth from the patch area when the dung patch was removed.

The second experiment included three defoliation treatments, viz. 1. Cut regularly to 1 in. (2.54 cm) in all three rings; 2. Cut to 21/2 in. (6.35 cm) in R2 and 1 in. (2.54 cm) in R3 and R4; 3. Control undefoliated.

In all three treatments there was a significant increase throughout the experiment in total yield of grasses around the dung patchy. The increase was confined to R2, but was still evident after 14 weeks. The greatest cumulative yield during tbe period of the experiment came from around the dung patches receiving the most intensively defoliated treatment.
ESTIMATES OF RESPIRATORY RATES AND LOSSES IN CUT SWARDS OF LOLIUM PERENNE (S321) UNDER SIMULATED HAYMAKING CONDITIONS
Authors: Pizarro E. A. , James D. B.
Published: April 2006

The rates of respiration in cut swards of Lolium perenne (S321) were measured while drying under simulated field conditions, the purpose of the experiment being to assess the extent of respiratory losses which can occur in the process of haymaking. Respiration measurements were made on the grass at different moisture contents during the drying process and also at different stages of growth. The results show that both the moisture content and the age of the grass had a significant infiuence on respiratory rates, consequently these factors can be expected to infiuence the DM losses which occur during haymaking. It was estimated that respiratory losses could amount to, at most, hetween 1.28 and 0.26 kg/100 kg DM, depending on the stage of growth at which the grass is cut
TILLERING IN GRASSES—ITS SIGNIFICANCE AND CONTROL*
Authors: Jewiss O. R.
Published: April 2006

Tillering is examined in relation to the morphology and habit of growth of the perennial herbage grasses; particular reference is made to the effects of cutting and grazing. The importance of tillering in establishment and regeneration or perennation of a grass sward is considered; greater importance is attached to the role of tillers in the regrowth of swards cut for conservation at the reproductive stage of growth. Amounts of regrowth are related to both the number and size of vegetative tillers present at the base of reproductive tillers at the time of cutting. The probable inhibition of the replacement tiller buds by the developing inflorescence is suggested as a reason for the poor growth of grass swards in the favourable environment of midsummer.

The physiological mechanisms which control tillering during reproductive development are examined. Spring and winter wheat (Triticum aestivum), Lolium temulentum and Phalaris tuberosa are used as physiological tools to demonstrate that tillering is restricted during reproductive development, and that stem extension may be more important than changes at the stem apex in controlling this restriction of tillering at the base of the inflorescence‐bearing stem. It appears from results of the application of a range of growth regulators that substances derived from the meri‐stematic centres, in either the elongating stem or the terminal meristem, indirectly control the metabolic activity of the lateral buds from which new tillers are derived. The degree of apical dominance is shown to depend on the light intensity in which the plants are grown. Finally, the physiological results are used to suggest reasons for the commonly found apparent inability of heavily fertilized perennial ryegrass (Lolium perenne) swards to regrow after cutting at the inflorescence‐emergence stage of growth.
A NOTE ON THE ZERO‐GRAZING OF BEEF CATTLE
Authors: Greenhalgh J. F. D. , Aitken J. N. , Reid G. W.
Published: April 2006

Groups of 8 steers weighing 300–400 kg (660–880 Ib) were rotationally grazed on a ryegrass‐dominant pasture for 115 days. The systems compared were zero grazing (Z), field grazing conducted at the same stocking rate (FC), and field grazing conducted at a stocking rate varied with the intention of giving the same liveweight gain per uiimal as zero grazing (FV). Mean daily liveweight gains were: Z, 0.98; FC, 0.78; FV, 0.90 kg/animal (2.2, 1.7 and 20 Ib/animal), and liveweight gains/unit area were in the ratio 100:78:85. Organic‐matter intake, measured on four occasions, was, on average, Z, 6.54; FC, 6.18; FV, 687 kg/head daily (14.4, 13.6 and 15.1Ib).

From these results it appears that a comparison of zero grazing and field grazing made at the same stocking rate is likely to underestimate the potential of field grazing for beef production from grass.
THE EFFECT OF CUTTING HEIGHT AND CUTTING FREQUENCY ON THE PRODUCTIVITY OF AN ITALIAN RYEGRASS SWARD
Authors: Binnie R. C. , Harrington F. J.
Published: April 2006

Three cutting heights, 1, 3 and 5 in. (2.5, 7.6 and 12.7 cm), and three cutting frequencies, 3, 6 and 10 weeks, were imposed on a pure sward of Italian ryegrass (Lolium multiflorum) cv. Irish. Lowering the cutting height increased the yield of DM, digestible DM, crude protein and crude fibre. Increasing the interval between cuts increased the yield of DM, digestible DM and crude fibre. The results are discussed in relation to other research findings and to the management of short‐term leys of Italian ryegrass.
SILAGE AND MILK PRODUCTION. A COMPARISON BETWEEN WILTED GRASS SILAGES MADE WITH AND WITHOUT FORMIC ACID
Authors: Castle M. E. , Watson J. N.
Published: April 2006

Fonr grass sUages made in May from the same herbage were compared io a 16‐week feeding experiment with 12 Ayrshire cows. The silages were made from herhage wilted for either 1 or 2 days, and with or without 1/2 gal formic acid per ton of herhage. The silages treated with acid were, on average, 5°C cooler than the untreated silages, had lower pH values, higher lactic acid contents, slightly higher DM and crude protein contents, and higher contents of digestible organic matter in the DM. The silages were fed ad lib. with a supplement of harley and groundnut cake. The intakes of silage DM were higher with the acid‐treated than with the nntreated silage. The mean daily milk yields on the silages made with and without the acid additive were 35.4 and 33.1 lb (16.1 and 15.0 kg), respectively, for the silage, wilted for 1 day and 34.2 and 32.2 lb (15.5 and 14.6 kg) for the silage wilted for 2 days. The effects of the treatments on the composition of the milk were small. It is concluded that the silages treated with formic acid additive were superior to the nntreated silages as a feed for dairy cows.
USES AND CAPABILITIES OF ELECTRONIC CAPACITANCE INSTRUMENTS FOR ESTIMATING STANDING HERBAGE
Authors: Currie P. O. , Morris M. J. , Neal D. L.
Published: April 2006

An electronic capacitance meter was used to estimate herbage yield from sown ranges in western USA. On an area in Arizona where the grass stand had heen sown broadcast, an r2 of 0.47 was obtained between the meter value and oven‐dry weigbt estimate. Excluding tbose plots with very large amounts of standing dead organic matter (OM), or very succulent plants which had not been sown, improved yield estimates.

Tests on pastures in Colorado in whicb seed had been drilled and tbe meter tested to evaluate performance in relation to drill rows showed that a common regression could be used for estimating yield. Metbods of placing the meter in relation to row directions are described which avoid a biased estimate of total pasture yield. Cutting the herbage in a 3‐dimensional manner improved the r2 values over those obtained by the usual 2‐dimensional cutting procedure. Separation of dead OM from living plant material did not significantly change the r2 values and showed that dead OM bad very little influence on the meter reading. This dead OM can contribute significantly to variation of the estimate about the regression line, however, and if differences in dead OM are substantial, sample sizes may need to be increased or sampling stratified to obtain an accurate yield estimate.

Pertinent literature on the evolution of electronic capacitance instruments for estimating herbage yields has been presented in Part 1 of this series (3). Tbe present evaluation is restricted to the herbage yield estimates from mechanically sown pastures. The Neal Electronics Model 18–612 meter was used to make the yield estimates.
THE INTAKE OF DRINKING WATER BY GRAZING DAIRY COWS. THE EFFECT OF WATER AVAILABILITY
Authors: Castle M. E. , Watson J. N.
Published: April 2006

In a 16‐week grazing experiment with six spring‐calved Ayrshire cows, drinking water was available to the animals in three different ways, and the effect on milk prodnction was studied. The water was available from a water howl in the cowshed for 2.8 h/day in Treatment A, from a trough in the field for 21.2h/day in Treatment B, and from hoth sources for a total of 24 h/day in Treatment C. The cows on all treatments were grazed in individual plots of intensively‐managed perennial ryegrass, stocked at the rate of 1 cow/0.22 ha (0.54 ac). The mean daily intakes of drinking water were 10.1, 15.3 and 15.5 kg (2.23, 3.37 and 3.42 gal)/cow, and the mean daily milk yields were 17.0, 17.2 and 16.8 kg (37.5, 37.9 and 37.0 lb)/cow in Treatments A, B and C, respectively; milk yields were not significantly different The herbage had an average DM content of 17.3%, and contained 19.6% crude protein and 66.5% digestible organic matter in the DM. The weight of water drunk was significantly and positively related to the DM percentage of the herbage, the air temperature and the daily hours of sunshine, and negatively related to daily rainfall. It is concluded that when dairy cows are grazing leafy herbage of high digestibility as their sole feed, the time during which drinking water is available may safely be restricted.
THE EFFECT OF COMPANION GRASSES ON TIMOTHY PRODUCTION IN SWARDS CUT FOR CONSERVATION
Authors: Frame J. , Harkess R. D. , Hunt I. V.
Published: April 2006

To assess the effect of companion grasses on timothy productivity, swards of timothy sown alone or with one of eight companion grasses were harvested as for silage four times per year for two years. The companion grasses were: diploid perennial ryegrasses S24 and S23; tetraploid perennial ryegrasses Reveille and Taptoe; meadow fescues S215 and S53 and cocksfoots Trifolium and S143. Averaged over the N application rates (226, 339 and 452 kg N/ha per year) the total herhage yields of timothy/companion‐grass mixtures were all significantly superior to that from timothy alone in the first year. Only perennial ryegrass S24 and the cocksfoot mixtures significantly outyielded timothy alone in the second year. Winterkill hecame evident in April of the second year and pure timothy and timothy/meadow‐fescue swards were least affected. Over all swards, timothy DM increased hy a mean of 19% from the first to the second year, compared with a fall of 20% in total herhage DM. The contrihution of timothy herhage to the mixtures was very low with companions other than meadow fescue. Late‐heading varieties were more compatihie than early‐heading varieties, and tetraploid ryegrasses were more compatihie than diploid ryegrasses. It is concluded that if the inherently valuahle characteristics of timothy are to he exploited, it should not he sovm with aggressive companion grasses.
THE RESPONSE OF S24 PERENNIAL RYEGRASS SWARDS TO IRRIGATION
Authors: Garwood E. A. , Tyson K. C.
Published: April 2006

The response of established perennial ryegrass swards to irrigation was compared over 2 years. The swards received 250 (N1) or 500 kg N/ha (N2) and were cut 4 times each year. Water was applied in 5 irrigation treatments according to the potential soil water deficit: the soil was partially, or fully returned to field capacity after cutting; returned to field capacity after cutting and then whenever a 25 mm deficit arose; irrigated with 25 mm water whenever a 25 mm deficit arose independently of cutting; or irrigated at minimum intervals of 14 days, provided that the deficit was then at least 50 mm.

There was little effect of irrigation on yield from the first cut in late May. Frequent irrigation gave the greatest increase in total annual yield (3.1 t/ha), hut partial irrigation after cutting was most efficient in use of water and equipment, provided that drought conditions were avoided.

High concentrations of N in the herbage were associated with low DM yields, hut more N (percentage N DM yield) was recovered from the irrigated than from the unirrigated swards. More N was recovered than was applied in the N1 treatment; less was recovered than was applied in N2. In the N1 treatment the nitrate concentration was <500 ppm hut it was 1000–4000 ppm in N2. There was no consistent effect of irrigation on nitrate or K concentration.
STUDIES IN RESPONSE TO NITROGEN
Authors: Hunt I. V.
Published: April 2006

The residual effects of 59, 118 or 177 kg N/ha applied to the primary growth of a ryegrass sward were measured in two successive regrowths as yields of fresh matter (FM), DM and digestible organic matter (DOM).

The first regrowths (RGl) harvested on 12 June followed primary growth (PG) harvests 8, 12, 16, 23, 29, 45 and 57 days after applying N on 16 Apr. The second regrowths (RG2) were harvested on 12 Aug., 62 days after RGl and 119 days after applying N.

Significant residual responses were shown in both regrowths which increased the annual responses substantially. Responses to the first increment of N, averaged over dates of primary growth harvests, were raised from 70.3 kg FM, 9.2 kg DM, and 5.6 kg digestible OM/kg N applied, for the primary growth, to responses for primary growth+2 regrowths of 140.8 kg FM, 22.5 kg DM and 13.9 kg digestible OM/kg N applied. For the second increment of N, negligible or negative primary growth responses of 19.0 kg FM, –0.68 kg DM and –0.68 kg digestible OM/kg N applied became 179.7 kg FM, 25.6 kg DM and 16.4 kg digestible OM/kg N applied for the sum of the 3 growths.

There were significant differences between the residual responses obtained for different dates of PG harvest. When PG was harvested 8 days after applying N, primary response was low or negligible; residual responses were high, and the total responses were 21.0 kg DM/kg N applied for the first N increment and 31.0 kg DM/kg N applied for the second. Similar effects were observed for FM and digestible OM. Residual responses to the second increment of N were greatest where primary growth was harvested 23 days after N application. Similar residual responses followed the primary growth harvest 29, 45 and 57 days after N application hut the total responses were reduced.

It is concluded that the very high residual responses to the second increment of N can only he explained in terms of increased availability of soil N.
INTENSIVE SET‐STOCKING OF DAIRY COWS
Authors: Hood A. E. M.
Published: April 2006

Farm‐scale trials with Ayrshire dairy cows were conducted in South‐West Scotland over two seasons to compare set‐stocking and paddock grazing at similar stocking rates and N fertilizer rates.

At a stocking rate of 1±9–2±0 cows/ac throughout the grazing season and a fertilizer N rate of about 400 units/ac, milk production per head from set‐stocked cows was equal to that from paddock‐grazed cows. No health problems arose as a result of applying fertilizer to the fields which were set‐stocked.

These trials hare established that set‐stocking is a viable system for the intensive management of dairy cows on grassland in the UK, but further work is necessary to determine whether paddock‐grazing has a higher potential for milk production than set‐stocking.
THE INFLUENCE OF SUPPLEMENTARY FEEDING ON THE HERBAGE INTAKE AND GRAZING BEHAVIOUR OF DRY COWS
Authors: Sarker A. B. , Holmes W.
Published: April 2006

The herbage intake and grazing behaviour of 4 dry cows on autumn grass receiving 2, 4, 6 or 8 kg concentrates/day, was assessed in a 4×4 Latin Square experiment.

Total OM intake increased from 11±5 kg/day with 2 kg concentrates to 13±6 kg/day with 8 kg concentrates. The average supplementary effect was 0±46 kg increase in OM intake/kg OM fed as concentrates.

Minutes per day spent grazing decreased from 495 with 2 kg concentrates to 359 with 8 kg. The mean decline was 22 min./kg concentrates or 28 min./kg OM in concentrates eaten. Herbage was eaten at an average rate of 47 min./kg OM.
GRASSLAND SURVEYS IN ENGLAND 1939–1959
Authors: Idle A. A.
Published: April 2006

The results of three sample surveys of grassland, carried out in England in 1939, 1947 and 1959, are reported. In 1939, the amount of agricultural land returned as permanent grass was at a record level. Nearly half of this was ploughed up during the Second World War. This was primarily for tillage crops, but the secondary aim was for old grass to be replaced by sown swards of better quality. The surveys showed that, during the 20‐year period, the quality of English grassland improved (a) because a greater proportion of the poorer swards was ploughed; (b) because greater use resulted in improvements in the botanical composition of the remaining old grass, and (c) because of the large increase in the use of sown grass in both arable and non‐arable farmings.