bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of precipitation regime on the management of three-course crop rotations in northern Syria
Authors: Keatinge J. D. H. , Dennett M. D. , Rodgers J. 
Published: March 2009

SummaryIn the 350–600 mm seasonal rainfall ecological zone in northern Syria three-course rotations are commonly practised under rainfed conditions. The precipitation regimes at three sites in this ecological zone have been examined. These have been shown to exercise a powerful influence on crop management, and an enhanced understanding of the effect of precipitation on crop productivity would therefore assist in the development of improved strategies of agronomic and rotational management. Considerable variability has been demonstrated in characteristic elements of the precipitation regime at the selected sites and this has indicated the unsoundnesa of applying general management recommendations to the ecological zone as a whole.
The influence of winter nutritional depressions on the growth, reproduction and production of cattle
Authors: Joubert D. M. 
Published: March 2009

1. During the period May 1948 to May 1952, a study was made of the influence of seasonal fluctuations in the nutritive value of the natural pastures in the Bankenveld region of the Transvaal, on the growth, reproduction and production of cattle. The paired method of investigation was adopted, each heifer maintained on grazing alone having a related counterpart of the same age which received supplementary feeding during the winter months. The former treatment was termed ‘Low plane’, and the latter referred to as the ‘High plane’. Four breeds were included in the investigation, viz. Friesians and Jerseys, and Shorthorns and Afrikaners, thus representative of both dairy and beef types. The latter breed also represented the stock indigenous to South Africa. Initially five pairs per breed were studied, but deaths and other causes depleted the numbers to twenty-eight head after 4 years of investigation.2. Since the investigation formed part of a series of studies which have been in progress at the University of Pretoria and Agricultural Research Institute during the past two decades, the results of which hitherto remained unpublished, a review is provided in the early chapters. To furnish some indication of the natural conditions ruling in the Bankenveld region, the agro-ecological background is discussed, particular attention being paid to physical and nutritional factors. It is shown that for at least 6 months of the year the climate tends to be subtropical, whilst the results of digestion trials on pasture samples, indicated serious nutritional depressions in the natural grazing during winter.
Studies in selective weed control III. The control of annual weeds in leguminous crops with 2:4-dinitro-6-secondary-butyl-phenol
Authors: Roberts H. A. , Blackman G. E. 
Published: March 2009

During 1947–9, field and pot experiments have been carried out first to assess the herbicidal properties of 2:4-dinitro-6-secondary-butyl-phenol, and secondly to determine its value for selective weed control in leguminous crops. In order to obtain precise estimates of the concentration required to produce a given percentage mortality of either weed or crops species, such experiments were so designed that the results are capable of probit analysis.From the data of field experiments on thirteen species of annual weeds, it is evident that there are wide variations in the concentration required to produce a standard kill. Irrespective of the species, susceptibility is greatest in the young seedling stage and there is a rapid increase in resistance with age. For example, with Raphanus raphanistrum between the cotyledon and pre-flowering stage a sixfold increase in concentration is needed to give a 90% mortality.
Studies in grazing management I. A comparison of the production obtained from close-folding and rotational grazing of dairy cows
Authors: Holmes W. , Waite R. , Fergusson D. L. , Campbell Jean I. 
Published: March 2009

1. An experiment was carried out from 3 May to 10 October 1949 to compare close-folding with rotational grazing of dairy cows. With close-folding the cows were moved daily to an area of fresh pasture which was calculated to supply the day's feed requirements; the rate of stocking ranged from 50 to 80 cows per acre. With rotational grazing the cows were stocked on pasture at the rate of 6–8 cows per acre and moved from one pasture to another at intervals of 5–14 days. Two uniform groups of Ayrshire cows were used, and each group spent a period on each system of grazing. Two pastures, a ryegrass-dominant old pasture and a cocksfoot-dominant ley, were used, and as far as possible the pasture grazed by both groups of cows was similar. Nitrogenous top dressings up to 104 Ib. nitrogen per acre in the season were applied uniformly to both the close-folding and rotational areas. No supplementary feeding was given to the cows.2. The best methods of close-folding practised gave 215 and 201 cow-days of grazing per acre with 550 gal. milk per acre from the cocksfoot ley and 582 gal. from the permanent pasture. Rotational grazing on the same two pastures gave 181 and 138 cow-days and 450 and 351 gal. milk per acre respectively.
Studies in soil cultivation: XI. The effect of inter-tillage on the sugar-beet crop
Authors: Russell E. W. , Keen B. A. , Mann H. H. 
Published: March 2009

Experiments on the effect of inter-row cultivation of sugar beet, carried out in the three years 1939–41 on a sandy loam, led to the following results:1. If the soil nutrients are in short supply hoeing or hand-weeding increases the yield of the beet, provided these operations are carried out before or shortly after singling.2. Hoeing is more effective than hand-weeding, but it cannot yet be said with certainty whether this is due entirely to more efficient weed destruction, or whether there is some additional effect, such as mulching.3. If adequate quantities of soil nutrients are present, inter-row cultivation has little effect on yield, and the crop can tolerate a considerable weed infestation without any effect on yield.The results for sugar beet on the heavy clay-with-flints soil at Rothamsted show:1. Additional hoeings after singling, above a modest minimum, have either no effect on yield or else depress it.2. On the one occasion when pre-singling cultivations were given, the yield was increased.3. In contrast with the Woburn results the effect of cultivation does not vary with, the level of manuring.
Gas and vapour movements in the soil: I. The diffusion of vapours through porous solids
Authors: Penman H. L. 
Published: March 2009

The dependence of the coefficient of diffusion, D, upon the porosity, S, of a granular solid is investigated experimentally. For steady state conditions, using carbon disulphide and acetone vapours, it is shown that a curve connecting D/D0 and S can be drawn which is independent of the nature of the solid, its moisture content and, within limits, its texture. For a limited range of values of S (0·0 < S < 0·7) a good approximation is D/D0 = 0·66S and over this range the diffusion coefficients are larger than those found by Buckingham for carbon dioxide.Investigation of the non-steady state shows that in soils the attainment of pressure equilibrium is retarded by adsorption, and it is suggested that Buckingham's low values for steady-state conditions can be attributed to premature observations of the diffusion rates; the steady state had probably not been attained when his measurements were made.
Wastage, length of productive life, replacement and depreciation of dairy cows
Authors: Pettit G. H. N. 
Published: March 2009

1. In the Eastern Counties of England, annual wastage from milk recorded dairy herds amounts to 29·3 % of the number of cows at the beginning of the year.2. Average length of productive herd life in milk recorded herds is 3·4 years.3. Average length of total productive life in milk recorded herds is probably a little more than 4 years. Average length of total productive life in all herds is probably longer, and may be of the order of 5 years.4. Deaths of cows are equivalent to 10·4% of the total wastage, and to a mortality rate of 3·0% of the number of cows at the beginning of the year.5. During the three-year period 1934–5 to 1936–7, cows leaving the herd realized an average of £10. 10s. 6d. per head. The average market value placed upon heifers when they entered the milking herd was £20. 14s. per head, while cows for replacement purposes cost an average of £22. 5s. per head.6. Of all replacements, 67·7 % are heifers, but not all of these are home-bred. In annual valuations, 49·0 % of cows are described as homebred, 50·6% as purchased and 0·4% as unknown.
Growth and development in the pig, with special reference to carcass quality characters: III. Effect of the plane of nutrition on the form and composition of the bacon pig
Authors: McMeekan C. P. 
Published: March 2009

It is impracticable to give a detailed summary of the many findings of.this experiment; attention is confined, therefore, to the major aspects and the general principles emerging.1. By quantitative control of the plane of nutrition, twenty closely inbred pigs have been made to conform to four major variations in the shape of the growth curve from birth to 200 lb. live weight. A high rate throughout (High-High), a high followed by a low rate (High-Low), a low followed by a high rate (Low-High) and a low rate throughout the period (Low-Low) afforded comparison between animals of the same weight but different age and between animals of the same weight and age but with differently shaped growth curves. The relative effects of the treatments upon the development of body proportions and anatomical composition have been studied.
The teart pastures of Somerset: I. The cause and cure of teartness
Authors: Ferguson W. S. , Lewis A. H. , Watson S. J. 
Published: March 2009

The scouring of cattle and sheep caused by the teart pastures of central Somerset is due to the presence of molybdenum in the herbage in amounts varying from about 20 to 100 parts per million in the dry matter.The scouring can be prevented and cured by feeding or drenching with copper sulphate. A daily dose of 2 g. copper sulphate for cows and 1 g. for young stock, is sufficient to cure and prevent the scouring on very teart land. Less copper sulphate may be enough on mildly teart land.
Observations on the survival of stored spermatozoa in the genital tract of the mare
Authors: Laing J. A. 
Published: March 2009

1. Twelve pony mares were inseminated at various intervals (18 days to within 24 hr.) before ovulation with spermatozoa which had been concentrated by centrifugation and stored for 24 hr.2. Of fourteen inseminations, only two, both within 24 hr. of ovulation, produced pregnancies.3. The survival time of the stored spermatozoa within the female tract was concluded to be somewhat less than 24 hr.4. It is suggested that successful inseminations with stored spermatozoa could be made 24 hr. after the injection of prolan.This work was carried out while holding the Miss Aleen Curt Memorial Veterinary Research Scholarship from the Royal College of Veterinary Surgeons.My thanks are due to Dr J. Hammond and Dr A. Walton for their help and encouragement and to Mr F. T. Day for the loan of the ponies and for his help and instruction in the technique of examination.
Some observations on the need for copper in the diet of fattening pigs
Authors: Braude R. 
Published: March 2009

1. The results of two trials involving twenty-four pigs did not provide a clue to the observed craving of pigs for metallic copper.2. There seems to be no advantage in supplementing a normal diet for fattening pigs which contains about 5 p.p.m. of copper with copper given in form of a solution of copper sulphate. The addition of a mixture of copper sulphate, manganese sulphate and iron pyrophosphate to the same normal diet had also no effect on the rate of growth of the pigs and their food consumption.3. The haemoglobin and copper contents of the blood appeared to be unaffected by the addition of copper to the diet. The copper content of the livers showed a tendency to be higher in the livers of the pigs receiving the copper supplements.
The behaviour of nitrogenous manures in the soil Part I. The loss of manurial nitrogen
Authors: Mann Harold H. , Barnes T. W. 
Published: March 2009

An attempt was made to determine what becomes of the nitrogen added to a poor soil in moderate quantities of organic manures or of ammonium sulphate. Losses by drainage, in two successive barley crops, and by fixation in an unavailable form in the soil were determined, and it was found that with every material used (including tare residues containing 3½% nitrogen, mustard plant residues containing 1½–2¼ nitrogen and pure ammonium sulphate) and with intensive cropping and leaching, not more than 40–51% of the added nitrogen could be accounted for at the end of the experimental period. The balance, it is suggested, must have disappeared from the system, possibly as gaseous nitrogen.Incidentally to the above, it would appear that after the first crop of barley the presence of the manurial additions of tare residues, and especially of ammonium sulphate, tends to hinder the formation of leachable nitrogen in the soil.
Ear distortion in barley and other cereals caused by spraying with MCPA and 2, 4-D
Authors: Large E. C. , Weston W. A. R. Dillon 
Published: March 2009

1. Trials made near Cambridge in 1949 and 1950, under ‘mild’ and ‘hard’ spring weather conditions respectively, have confirmed that the findings of Aberg & Denward in Sweden, and of Pedersen, Andersen & Hermansen in Denmark, concerning distortions in barley caused by MCPA and 2,4-D, are also valid under English conditions.2. Damage to barley caused by the application of MCPA and 2,4-D up to the 2-leaf and early 3-leaf stages may be recognized by the occurrence of many tubular leaves and bowed or trapped ears. As little as 2 lb./acre of 2,4-D, as the amine salt, applied at this stage may also cause severe stunting of theplants with distortion of the roots.3. Damage to barley by the application of MCPA and 2,4-D at the 3–4-leaf stages may be recognized by the occurrence of tweaked ears. The application of as little as 2 lb./acre of MCPA, as the sodium salt, at these stages may cause tweaking in over 50% of the ears. 2,4-D (as amine) at the same dosage causes more distortion. Although the reduction in yield due to such tweaking may be slight, the grain sample is irregular in size, with a number of naked grains, and malting quality may be reduced.
Chemical composition and the feeding value of cotton-seed hulls
Authors: Hussain Anwar , Halim Abdul , Wahhab Abdul 
Published: March 2009

With the installation of more factories for the decortication of cotton-seeds in Pakistan, the utilization of cotton-seed hulls as a feed is likely to assume great importance. During 1949–50, the writers made determinations of the chemical composition and the feeding value of Pakistan cottonseed hulls by conducting a digestibility trial on dry Sahiwal cows. They are found to contain 39.89–56.47% total digestible nutrients (mean value = 48.68%) and 0.0–0.38% digestible protein. It was observed during the trials that the cows could eat about 20 lb. of hulls per head per day without difficulty. The cows also ate hulls in preference to wheat straw.Being low in calcium and phosphorus, cotton-seed hulls should not be used as a sole roughage for long periods, unless supplemented with calcium or phosphorus in mineral form, or preferably with silage, legume hay or green fodder of good quality.Pakistan cotton-seed hulls appear to be equal, if not better, than wheat straw as a cattle feed. From the economic point of view, hulls should be used as a cattle feed only if they are purchasable at about the same price as wheat straw.
Biological aspects of soil fertility
Authors: Neilson-Jones W. 
Published: March 2009

1. These researches were undertaken in order to analyse and define with precision the causes of infertility in a heath soil at Wareham Forest, Dorset.2. The presence of substances actively inimical to growth has been confirmed and the origin of the resulting toxicity established.3. A new technique for biological analysis, the nutrient-agar-film method, makes it possible to estimate the relative degree of toxicity in any given sample, thus facilitating development of methods of laboratory control for elimination and redistribution of the factor or factors responsible.4. It has been proved that the toxic substances are of biological origin and that they operate directly by inhibiting fungal growth. The resulting biological inertia is exemplified by almost complete cessation of cellulose decomposition. Following upon this inertia are indirect effects of a secondary character on growth of the higher plants, in the case of trees restricting root growth, impeding mycorrhiza formation, and curtailing supply of nutritive requirements.5. Justification for the use of organic composts for relieving the observed infertility under field conditions has been provided by laboratory experiments proving that removal of toxicity and profound alteration of the organic substrate and soil bionomics follow addition of compost. Changes so induced are self-propagating and the effects on growth persistent.6. The bearing of these results on fertility in other natural soils and in cultivated soils is discussed.
Soil studies in relation to geology in an area in north-east Scotland: Part I. The mineralogy of the soil parent materials
Authors: Hart R. 
Published: March 2009

1. An account is given of the distribution of four separate boulder clays, which form the parent materials of the soils of eastern Kincardineshire.2. The mineral composition of the fine sand fractions of the boulder clays is given.3. The boulder clays, notwithstanding colour similarities, have been shown by mineralogical examination to be distinct.4. The middle boulder clay, largely influenced by rocks of Old Red Sandstone age, is shown to have a higher proportion of ferromagnesian silicate minerals than soils from glacial drifts similarly derived elsewhere in Scotland.
Marsh spot of peas: a manganese deficiency disease
Authors: Piper C. S. 
Published: March 2009

By growing peas in water cultures with carefully regulated amounts of manganese, the effects of a deficiency of this element have been studied.Complete absence of manganese produces a mottling of the younger leaves and death of the growing tip as previously reported. The plant does not reach the flowering stage.Small amounts of manganese, insufficient for normal requirements, enable increased growth and seed formation. The seeds show marsh spot lesions, the severity of the lesions being greater at the lower manganese concentrations.Normal growth and sound seed are produced when sufficient manganese is present in the nutrient solution.Marsh spot results from a partial deficiency of manganese, the amount available to the plant being sufficient for its normal vegetative requirements but not for healthy seed production.
The effect of plant spacing, nitrogen fertilizer and irrigation on the appearance of symptoms and spread of virus yellows in sugar-beet crops
Authors: Heathcote G. D. 
Published: March 2009

SUMMARYSatisfactory comparisons of the incidence of virus yellows in sugar-beet fields or experimental plots with different amounts of N fertilizer can be made from visual symptoms early in the growing season, but not later because dressings of N fertilizer may then mask or delay the appearance of symptoms. Sugar-beet plants in the field infected with beet mild yellowing virus (BMYV) are less likely to show symptoms than those with beet yellows virus (BYV), and plants with BMYV in the glasshouse often fail to show clear symptoms.Crop yield will be affected by the spread of viruses and colonization of plants by aphids, which in turn are affected by such factors as plant density, nitrogen supply and irrigation. The presence or absence of virus diseases and of aphids should therefore be considered during studies on the effects of these agronomic factors on the growth and yield of sugar beet. Where ample rather than little N fertilizer is used a small increase in the percentage of plants infected with yellows can be expected, and aphids will be more numerous, if plants are not treated with insecticide. Irrigation may also increase yellows incidence (e.g. from 16% to 20% of plants at Broom's Barn in 1967), but any loss of potential yield from increased virus incidence will be small compared with that gained from the use of fertilizer or irrigation. However, plant density can appreciably affect yellows incidence. For example, at Broom's Barn in 1972, 51% of plants in crops with 17500 plants/ha contracted BMYV but only 15 % of plants in crops with 126500 plants/ha. The less dense crop lost 3–4% more of its potential yield due to yellows than the dense crop; this represents a difference due to virus of about 0·25 t sugar/ha.
An empirical law describing heterogeneity in the yields of agricultural crops
Authors: Smith H. Fairfield 
Published: March 2009

Using data from a blank experiment with wheat it was found that the regression of the logarithms of the variances for plots of different areas on the logarithms of their areas was approximately linear. A graphical review of variances, etc., reported in the literature for thirty-nine other blank experiments indicates that the results of most such experiments conform to the same law.It is shown that the above law can be generalized (so as to be applicable to any size of field) by applying a certain adjustment to the regression coefficient b', so as to give a modified coefficient b applicable to an “infinite” field.From this generalized relationship there has been deduced an expression ((4), p. 16) to indicate average relative efficiencies to be expected for randomized block experiments with varying numbers of plots per block in a field for which the coefficient b is known.A formulae (5), which may be used to estimate the most efficient size of plot for any given experiment, has also been deduced. The cost of using plots of other than the most efficient size is indicated graphically in Fig. 7.
Sheep nutrition: II. Determinations of the amounts of grass consumed by sheep on pasturage of varying quality
Authors: Woodman H. E. , Evans R. E. , Eden A. 
Published: March 2009

A technique for measuring the appetites of sheep on pasture is described.Results are given to show that sheep consume a bigger ration, in terms of lb. dry matter, when on pasture than when subsisting out-of-doors on the winter type of diet composed of hay, swedes (or kale) and concentrates. This difference was noted even on grass that had deteriorated in quality, in one case as a result of hot, dry weather in early summer, and in a second case as a consequence of cold, dry weather in spring. With young, leafy pasturage at its best, however, the distinction is most marked.In the March of 1934, to quote but one example, four pure-bred Suffolk wethers, of live-weight varying from 120 to 181 lb., were shown to consume, on a diet of concentrates (350 g. daily), swedes (ad lib.) and chaffed hay (ad lib.), only 80–88 per cent of the amounts of dry matter predicted on the basis of Wood's feeding standards. During the following May, when grazing leafy pasturage of very good quality (digestion coefficient of organic matter = 81·l per cent), the appetites of the same sheep (range of live-weight now from 137 to 201 lb.) were found to have undergone a striking stimulation, the mean daily consumption of dry matter now being from 104 to 117 per cent of the amounts predicted from the standards. This implied that the sheep were consuming 1·13, 1·37, 1·13 and T53 lb. respectively more dry matter per day than they would have eaten had the diet consisted of hay, concentrates and swedes. The increased appetite is to be attributed to the superior palatability of the young grass.