bluuebunny/crossref_metadata_2025_split huggingface dataset:
SOME PHYSIOLOGICAL CHARACTERISTICS AND THE AGRONOMIC IMPORTANCE OF DIPTERA DAMAGE TO GRASSES
Authors: Emecz Tibor I. 
Published: April 2006

Shoot‐fly larvae cause considerable damage to cultivated grasses; it is greatest when overwintering tillers are lost, resulting in delayed emergence, decreased number of flowering heads and reduced yield of dry matter.An increase in the number of tillers, which often follows the damage, cannot counter‐balance the losses because the new tillers are smaller.Different varieties within species, and different genotypes within varieties, show varying degrees of susceptibility to damage, and of capacity to recover from it. Favourable growing conditions promote recovery and reduce losses.Non‐cultivated grasses and unploughed leys are sources of infection, not only to cereals but also to cultivated grasses, and it is advisable not to put single plants or seed areas adjacent to old swards. The glasshouse is a special source of infection as it provides conditions favourable for the flies to produce extra generations at unusual times.The importance of further investigations and the development of more economical protective techniques is stressed.
INTER‐VARIETY VARIATION IN RHODES GRASS (CHLORIS GA YANA KUNTH)
Authors: Hutton E. M. 
Published: April 2006

The characters in 25 varieties of Rhodes grass introduced from Africa have been studied with a view to improving on Australian Commercial. Only the diploid Katambora and a tetraploid variety from Kenya appeared to possess a higher yield potential than Commercial. Sixty per cent of the varieties are tetraploid, the rest diploid. A degree of association occurred between the level of ploidy and some Rhodes grass characters.Although Rhodes grass appears to be xenogamous, all the critical evidence points to an apodictic form of reproduction. Viable caryopses were extracted from harvested “seed” and the percentage of florets setting caryopses was low. Rhodes grass caryopses germinate fairly well and have a higher resistance than usual to irradiation by gamma rays.
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.
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.
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.
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.
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

ABSTRACTC. 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

ABSTRACTA 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

ABSTRACTGrass 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

ABSTRACTResidual 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

ABSTRACTA 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

ABSTRACTStanding 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

ABSTRACTThe 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.