bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the accuracy of three measurements of heifers.
Authors: Sanders H. G. 
Published: March 2009

Six heifers have been measured every week, for 5 weeks before calving and 6 weeks after calving, with the object of ascertaining what errors would be introduced by taking one set of measurements during such a period, as representing the size of the heifer at parturition.The gross standard error was found to be 0·834 cm. in measuring shoulder height and back length and 0·605 cm. in measuring height to the elbow.During the period these heifers were growing as follows: shoulder height, 0·159 cm. per week; back length, 0·124 cm. per week; and elbow height, 0·079 cm. per week.When allowance was made for growth the net personal errors of measurement gave standard errors of 0·636 cm., 0·727 cm., 0·547 cm. respectively for shoulder height, back length and elbow height, and the errors were, apparently, distributed normally.
The effects of grazing intensity on herbage consumption and animal production: II. Longer-term effects in strip-grazed dairy cows
Authors: Greenhalgh J. F. D. , Reid G. W. , Aitken J. N. 
Published: March 2009

1. The object of the experiment was to determine the effects on the diet and production of grazing dairy cows of providing different quantities of herbage over a relatively long period.2. Three groups of five Ayrshire cows were strip grazed on areas supplying (A) 25, (B) 35 or (C) 45 lb D.M. per cow per day, for a total of 11 weeks. Three swards were used in succession, and measurements of herbage intake, milk production and live-weight changes were made over the last 10 weeks.3. Mean intakes for treatments A–C, respectively, were 23·9, 25·6 and 26·4 lb organic matter per cow per day, and milk yields were 30·4, 30·8 and 32·8 lb. Differences in digestibility between treatments were small, even when the cows grazed poor herbage in which the organic matter was only 68 % digestible.4. The treatments had no significant effects on milk composition or live-weight gain, although the latter was less for treatment A.
Soil temperatures under cotton in Egypt
Authors: Taylor E. McKenzie 
Published: March 2009

The results of the investigation may be summarised as follows:(1) In Egypt, during the periods of germination and increase in height of the cotton plant, the soil temperatures are rising and the amplitude of the temperature wave is at its maximum.(2) In Egypt, the maximum soil temperatures decline while the minimum soil temperatures remain constant, thus resulting in a gradual decrease in the amplitude of the daily temperature wave during the branching and flowering periods.(3) In Egypt, throughout the soil zone occupied by the roots of the plant, the temperature is the same, the amplitude of the daily temperature wave small, and the temperature is constant during the boll development and maturation periods.(4) The main effect of irrigation on soil temperatures is to reduce the amplitude of the daily temperature wave, no sudden change of temperature in the root zone taking place.(5) From a consideration of the range of air temperature in other cotton producing countries, it seems probable that the characteristics of the soil temperatures during the boll development and maturation periods are the same for all countries.
On the algae of some normal English soils
Authors: Muriel Bristol Roach B. 
Published: March 2009

An account is given of an investigation of the alga-flora of four English soils by means of dilution cultures of freshly gathered samples of soil from the top, second, fourth, sixth and twelfth inch depths and from the top 6 in. mixed. A counting method is described applicable to the green algae and diatoms, by means of which it is shown that these algae are distributed throughout the top 12 in. of soil, though at the sixth and twelfth inch depths they are considerably less numerous than nearer the surface. At the fourth inch depth the numbers of individuals are not significantly smaller than on the surface and may be even greater.The unmanured plot of Broadbalk wheat field was found to contain the same main species as the adjacent farmyard manure plot but was poorer in numbers of individuate. Thirty-five species are described from each plot; they seem to be divisible into two groups, the true soil forms and casual species. Of the true soil forms some grow equally well on the surface and in the lower layers, whereas others are more numerous on the surface than within the soil. The same main types were also obtained from Barnfield and from a cottage garden, but the blue-green species were less conspicuous in both of these soils.Experimental evidence is given to show that many of the algae of the soil exist in a vegetative condition rather than a resting condition. Biological notes are made on some of the more important or interesting soil species.
Soil temperatures in Egypt
Authors: Taylor E. McKenzie 
Published: March 2009

1. The soil temperatures in Egypt at a number of depths have been recorded by means of continuous recording thermometers. In general, the records show that the amplitude of the temperature wave at the surface of the soil is considerably greater than the air temperature wave. There is, however, a considerable damping of the wave with depth, no daily variation in temperature being observed at a depth of 100 cm.2. No definite relation between the air and soil temperatures could be traced. The maximum air temperature was recorded in May and the maximum soil temperature in July.3. The amplitude of the temperature wave decreases with increase in depth. The decrease in amplitude of the soil temperature wave is not regular owing to variations in the physical properties of the soil layers. Between any two depths, the ratio of the amplitudes of the temperature waves is constant throughout the year. The amplitude of the soil temperature wave bears no relation to the amplitude of the air temperature wave.4. The time of maximum temperature at the soil surface is constant throughout the year at 1 p.m. The times of maximum temperature at depths below the surface lag behind the time of surface maximum, but they are constant throughout the year. When plotted against depth, the times of maximum at the various soil depths lie on a straight line.
The moisture equivalent of heavy soils. II
Authors: Joseph A. F 
Published: March 2009

1. The moisture equivalent of pure clay preparations varies with (a) the chemical composition, (b) the method of separation if centrifuged, (c) the replaceable bases.2. The imbibitional water content also shows a close connection with the above variables.3. Good additive relationships can only be obtained from series of soils of the same nature and in some cases, if taken at the same depth. This is, at any rate in part, due to differences existing in composition and properties between clay separated from soils and subsoils.4. Pure silt fractions from different soils showed marked differences in their chemical composition and moisture equivalent.
Soil permeability in the Eastern Gezira
Authors: Greene H. 
Published: March 2009

An account is given of studies of moisture content in the field. The results are in agreement with Joseph's (1) view that the relation between salt content and fertility is chiefly due to the effect of sodium salts on soil texture. At the Gezira Research Farm a single watering moistens only the top 3 ft. of soil, although in the course of an irrigation season some small percolation continues below this depth. The water requirement of cotton in this region is extremely high and danger of water strain is correspondingly acute. The effect of 14 days' flooding is taken as a measure of permeability in the field and this test was applied with confirmatory results to two areas whose agricultural value had previously been gauged both by laboratory studies and by field observation of the soil profile. The genesis of the Gezira soil is briefly discussed with regard to the relation between salb content and fertility and with regard to the use of gypsum as a corrective. Marked improvements in permeability have been brought about by applications of this substance.I am indebted to Dr A. F. Joseph, under whose direction this work was done, for his useful suggestions and for facilities placed at my disposal.
The periodicity and duration of oestrus in zebu and grade cattle
Authors: Anderson James 
Published: March 2009

Records are given for 1130 oestrous cycles in zebus and 678 cycles in grades. The mean length was 23·03 days in zebus and 22·42 days in grades. The mean duration of oestrus was 4·78 hr. in zebus. 7·40 hr. in grades. Neither exposure to additional light at night nor feeding a supplementary ration had any effect on the cycle of oestrus.Seasonal variations in both the cycle and oestrus occurred in zebus, but in grades they were much less marked. An association between climatic conditions and sexual function was noted in that a season of increased temperature and sunshine was associated with increased sexual function and vice versa.
A radiographic study of the development of the skeleton of the foetal pig
Authors: Wenham G. , McDonald I. , Elsley F. W. H. 
Published: March 2009

SUMMARYA radiographic study was made of the skeleton of eighty-three foetuses from twenty-four litters killed between the 37th and 112th day of gestation. Measurements were taken, from radiographs, of the length and depth of the skull and the length of the diaphyses of the humerus, radius, ulna, metacarpus, ilium, ischium, femur, tibia, fibula, calcaneum and metatarsus. Skull length, humerus and metatarsus were selected for statistical analysis. The litter mean lengths of the diaphyses were studied in relation to age, weight, and age and weight jointly. Within-litter differences in bone measure-ments were closely associated with foetal weight differences.The relationships of litter mean log. lengths of the skull, humerus and metatarsus upon age were best fitted by a quadratic regression, and with mean log. foetal weight by linear function regressions. A joint regression incorporating both age and weight of the foetuses fitted the data significantly better than equations based on weight or age alone. Skull length was found to have a growth coefficient between the 51st and 112th day of gestation significantly lower than that of the other bones examined. The age at which the primary and secondary ossification centres appear was studied.
Studies on the relation between cultivation implements, soil structure and the crop II. The effects of the Fowler “Gyrotiller” on the soil
Authors: Culpin Claude 
Published: March 2009

A general account is given of four experiments in which the action on the soil of the Fowler “Gyrotiller” has been compared with that of the traditional cultivation implements. The gyrotiller has produced well-marked changes in the soil on both heavy and light land. These changes have been demonstrated and recorded by tests of the compactness, the resistance, the degree of comminution and the permeability of the soil.On the heavy land, the initial effect has been to produce a very loose and open soil. This has gradually settled down until, after the end of the first winter, no difference in compactness was demonstrable by means of the revolver test. But the resistance of the soil, measured by a special recorder and by plough drawbar tests, has remained demonstrably lower on the gyrotilled plots than on the controls for a considerable time after this, and a method of soil fixation has shown that small cavities persisted for more than a year. In one experiment, differences in resistance have been shown to exist up to 19 months after gyrotilling.
The effects of ammonium and nitrate nitrogen on the growth of perennial rye grass
Authors: Lewis A. H. 
Published: March 2009

The results show clearly a more rapid and greater uptake of ammonium than of nitrate nitrogen by perennial rye grass grown in a sand-bentonite medium ofpH 7·61. The extent to which the extra uptake with added ammonia was reflected in increased yields was dependent upon the age of the grass.Except in the very early stages the percentage nitrogen content of the herbage was higher where nitrate nitrogen was applied than where ammonium nitrogen was applied. This indicates that any nitrate absorbed by the plant was less, efficient in increasing yields than was ammonium nitrogen.The percentage P205content of the grass was higher where the nitrogen was applied in the ammoniacal form than where it was applied as nitrate, and it appears that this greater P205uptake with ammonium nitrogen resulted in increased growth.
The effects of different methods of castration and docking on the growth of lambs
Authors: Garner F. H. , Sanders H. G. 
Published: March 2009

1. Two methods of castrating male lambs have been compared—the Burdizzo and knife methods. No difference was found in subsequent growth rate.2. Two methods of docking male and female lambs have also been compared—searing and crushing with the Burdizzo. No difference was found in subsequent growth rate.3. There was a tendency for ram lambs to have a higher initial weight than ewe lambs, and their rate of growth between the ages of 2 and 10 weeks was definitely greater than that of ewe lambs.
The effect of applying a nitrogenous fertiliser to wheat at different stages of growth
Authors: Watson D. J. 
Published: March 2009

The effect of applying a nitrogenous fertiliser to wheat at seven different times and three rates, was studied in pot culture. It was found that the later the time of application the smaller was the increase in the yield of total dry matter and of straw. The increase in the yield of grain, on the other hand, was constant for the first six times of application, the last of which was made on May 25, but a later application made after ear emergence produced no increase.Analysis of the grain yield showed that early application produced its effect by increasing the number of ears per plant. Later applications caused a smaller increase in ear number, but also increased the number of grains per ear and 1000-corn weight. There was no evidence of a critical time for tiller formation such as has been postulated by Doughty and Engledow.The increase in total nitrogen uptake was equal for all times of application, but the ratio of nitrogen in grain to nitrogen in straw and chaff was greater, the later the time of application.The writer wishes to thank Messrs A. M. S. Clarke, G. T. Detlefsen and S. A. W. French for much help with the experimental work, and Mr R. G. Warren for making the nitrogen determinations.
The effects of a wide range of nitrogen application rates on the yields from a perennial ryegrass sward with and without white clover
Authors: Reid D. 
Published: March 2009

SUMMARYA series of twenty-one nitrogen fertilizer rates ranging from 0 to 800 lb nitrogen/acre (897 kg/ha)/annum was applied on a pure S. 23 perennial ryegrass sward and on an S. 23 ryegrass sward containing S. 100 white clover. Total yields of herbage dry matter and crude protein from both swards at all the nitrogen rates were determined each year by cutting the herbage five times at approximately the same stage of growth on each occasion. Four-parameter growth curves relating herbage yield to nitrogen rate were fitted to the data, and are presented for the first 3 years of the experiment. On the pure-grass sward the response of dry-matter yield to nitrogen rate was almost linear between the 0 and 300 lb nitrogen/acre (336 kg/ha) rates, then it decreased steadily, becoming non-significant about the 500 lb/acre (560 kg/ha) rate. In contrast the response of crude-protein yield was virtually linear from the 0 to the 600–700 lb nitrogen/acre (673–785 kg/ha) rates. The inclusion of white clover in the sward increased the yields of dry matter and crude protein at the low nitrogen rates, but decreased the responses, with the result that the yields and responses of the grass + clover sward were not significantly different from those of the pure-grass sward at nitrogen rates above about 300 lb/ acre (336 kg/ha). In terms of profitability at present fertilizer prices the optimum nitrogen rate for dry-matter production on both swards was estimated to be 400–450 lb/ acre (448–504 kg/ha), whereas that for crude-protein production was greater than 600 lb/acre (673 kg/ha). The value of clover in a sward receiving nitrogen fertilizer is discussed.
A comparison of entire and ovariectomized beef heifers treated with ethylestrenol
Authors: Ocariz J. L. Hubard , John A. Little , Robertson I. S. 
Published: March 2009

SUMMARYTwenty-eight Hereford cross Friesian heifer calves aged 3 months were allocated in randomized blocks to two main treatments, namely, ovariectomy (spaying), performed by flank laparotomy, and anabolic steroid oral administration (Ethylestrenol). The cattle were tied in stalls and individually fed ad libitum on a ‘barley-beef’ type cereal mixture until slaughtered weighing approximately 340 kg.Ovariectomy reduced overall rate of live-weight gain and food conversion efficiency but differences were not significant. Spayed heifers, however, grew significantly taller than entires. Although fat and bone proportions of the side were increased slightly, carcass grading and composition were not appreciably altered by ovariectomy.Steroid treatment failed to improve performance but lean content of the side was slightly increased. This failure in response may have been due to incorrect dosage.
The effect of phosphate and potash fertilizers on cut and grazed grassland
Authors: Brockman J. S. , Shaw P. G. , Wolton K. M. 
Published: March 2009

SUMMARYAn experiment was carried out over a 5-year period on a grass/clover sward at North Wyke to compare three methods of experimental management—individually grazed plots, communally grazed plots and cutting with removal of herbage. Responses to phosphate and potash fertilizers under each management were measured.P fertilizer increased grass yields in the first 4 years and decreased clover yields in the last 2. In almost all respects cut and grazed sward responded similarly to P. Fertilizer K had no effect on grass yield but markedly increased clover yield and raised herbage K content. Grazed swards developed a higher herbage K content than cut swards, and K fertilizer increased it more in the fourth and fifth years on the individually grazed than on the communally grazed plots. Thus communal grazing resulted in appreciable transfer of K from plot to plot in animal returns.It is concluded that whilst cutting management may be used for short-term experiments, its use in long-term experiments gives different results from grazing. Communal grazing can lead to the transfer of N and K effects from plot to plot, so that plots must be grazed individually except perhaps where P is the only variable nutrient.
Three-valent manganese in soils
Authors: Dion H. G. , Mann P. J. G. 
Published: March 2009

1. A fraction of soil manganese soluble in buffered pyrophosphate solutions has been identified as three-valent manganese, present in the extract as a soluble complex salt of mangani-pyrophosphoric acid H[MnP3O7].2. Evidence is given to show that a very significant part of soil manganese may be present as three-valent manganese, and that the product of oxidation of divalent manganese in soils is three-valent manganese. In any soil where the production of divalent manganese by reducing processes is going on at any appreciable rate, the oxidation of divalent manganese will supply three-valent manganese, which may therefore be expected to form a relatively large part of the manganese of certain soils.
Cold tolerance and winter hardiness in Lolium perenne: I. Development of screening techniques for cold tolerance and survey of geographical variation
Authors: Lorenzetti F. , Tyler B. F. , Cooper J. P. , Breese E. L. 
Published: March 2009

SUMMARYExperiments were devised to establish suitable techniques of screening seedling material of Lolium perenne for cold tolerance under controlled conditions: these techniques were then used to distinguish between varieties and ecotypes from contrasting climatic regions. For the wide range of material used, greatest discrimination was achieved by 14 days hardening at 2 °C and 8 h photoperiod, followed by 2–4 days freezing at -8 °C in the dark. There were indications that the light intensity and/or temperature before and during hardening could considerably modify the cold tolerance.The most useful criterion of cold tolerance was the percentage of tillers surviving 14 days after thawing. In some instances, death of tillers and whole plants continued after this time, and this tendency appeared to be related to growth habit; southern ecotypes were particularly susceptible.Varieties from north Europe were generally more cold tolerant than ecotypes from the Mediterranean region, but tolerance depended also on the altitude of the original habitat. The cold tolerance of a population could, in part, be related to the average lowest temperature in the coldest month and in part to environmental conditions of solar radiation and/or temperature during the autumn in its place of origin.Along with the experiments under controlled conditions, spaced plants of the same populations were grown in the field in order to evaluate winter hardiness under local conditions. The overall correlation between winter hardiness in the field and cold tolerance as assessed in the growth rooms was not high. Results from one year's field testing showed that indigenous varieties such as S. 23 and S. 24 were more winter hardy than foreign ecotypes and varieties, even if these came from colder climates and showed greater cold tolerance in the growth room.
Comparisons of kieserite and calcined magnesite for sugar beet grown on sandy soils
Authors: Draycott A. P. , Durrant M. J. 
Published: March 2009

SUMMARYTwenty-three experiments between 1968 and 1971 compared the effect of no magnesium, 50 and 100 kg/ha magnesium as kieserite and 100 and 200 kg/ha magnesium as calcined magnesite, on yield and magnesium uptake by sugar beet. On average, 100 kg/ha magnesium as kieserite increased the mean sugar yield of 7·55 t/ha by 0·17 t/ha whereas 200 kg/ha magnesium as calcined magnesite increased it by only 0·08 t/ha; on fields with less than 15 ppm exchangeable magnesium the magnesium fertilizers increased sugar yield by 0·34 and 0·10 t/ha respectively and there was no response to either fertilizer when the soil contained more than 25 ppm of exchangeable magnesium.100 kg/ha magnesium as kieserite or calcined magnesite increased magnesium in the dry matter of tops by 0·091 and 0·040% and of roots by 0·013 and 0·004% respectively. Giving 100 kg/ha magnesium as kieserite or calcined magnesite increased uptake of the element in August by 5·1 and 2·6 kg/ha respectively. Differences in soil pH did not influence the uptake of magnesium from kieserite but they greatly affected uptake from calcined magnesite. On the slightly acid soils, the fertilizers were almost equally effective but at pH > 7·6 little magnesium was taken up from calcined magnesite. Glasshouse experiments showed that grinding the calcined magnesite increased the availability of the magnesium.
The effect of the height of defoliation on two clones of perennial ryegrass
Authors: Simons R. G. , Davies Alison , Troughton Arthur 
Published: March 2009

SUMMARYA significant interaction between genotype and cutting height was found in an experiment conducted to investigate regrowth from cutting heights of 2 cm and 5 cm above ground level in two contrasting genotypes with fast and slow rates of leaf appearance. There was, however, no evidence that production of herbage above the initial cutting height was increased by raising the height of cutting. This observation, and the difference between the genotypes, can be explained not only in terms of differences in the proportion of total above-ground parts harvested, but also in the scale of losses of leaf tissue by death.