bluuebunny/crossref_metadata_2025_split huggingface dataset:
The non-persistence of bacterio-toxins in the soil
Authors: Hutchinson Henry Brougham , Thaysen Aage Christian 
Published: March 2009

The experimental results submitted in the preceding pages may be summarised as follows:Seven English soils have been examined in order to ascertain the validity of Greig Smith’s claim that partial sterilisation effects may be due to the destruction of bacterio-toxins in the soil. The results obtained with six of these soils show that:1. The untreated extracts of these soils varied largely in their suitability for the growth of the test organism (B. prodigiosus). In some instances vigorous growth occurred; in others the numbers of introduced organisms fell to a minimum.2. Treatment of the extracts by heat (which was supposed to result in the destruction of “toxins”) invariably led to still further bacterial decreases.3. Extracts of soils treated with antiseptics (which are not supposed to destroy “toxins”) were on the whole more favourable for growth than those of untreated soils. Such extracts were found to have appreciably more organic nitrogen compounds than extracts of untreated soils.
On the decomposition of cellulose by an aerobic organism (Spirochaeta cytophaga, n. sp.).
Authors: Hutchinson Henry Brougham , Clayton James 
Published: March 2009

From the foregoing account the following summary may be given:1. Examination of Rothamsted soils on different occasions has revealed the presence of an organism capable of breaking down cellulose with comparative ease.2. This organism presents a number of features of morphological and physiological interest. Morphologically, the organism appears to possess greater affinities with the Spirochaetoideae than with the bacteria and the name Spirochaeta cytophaga is, therefore, suggested.3. While the spirochaet is capable of considerable vegetative growth as a sinuous filamentous cell, it also appears to pass through a number of phases which terminate in the production of a spherical body (sporoid) which differs in a number of respects from the true spores of the bacteria. Germination of the sporoid again gives rise to the filamentous form, which possesses perfect flexibility and is feebly motile. The latter does not apparently possess flagella.4. Spirochaeta cytophaga is essentially aerobic; its optimum temperature is in the region of 30°. Both the thread and sporoid stages are killed by exposure to a temperature of 60° for ten minutes.5. The nitrogen requirements of the organism may be met by a number of the simpler nitrogen compounds—ammonium salts, nitrates, amides and amino-acids. Peptone is also suitable in concentrations up to 0.025 per cent. Stronger solutions, e.g. 0.25 per cent., lead to marked inhibition of growth. The organism fails to grow on the conventional nutrient gelatine or agar.
Observations on soil protozoa
Authors: Cutler D. Ward 
Published: March 2009

1. It has been shown that the direct counting method for soil protozoa devised by Kopeloff and Coleman for use in liquid media gives results entirely comparable with those obtained by a dilution method.2. The factors governing the relation between the protozoa and the soil particles are those of surface action, and the capacity of various substances, sand, soil and clay, for retaining these organisms is specific and constant.3. Coarse sand is capable of withdrawing per gram approximately 145,000 amoebae and flagellates per c.c. from a suspension of any strength. Fine sand withdraws approximately 980,000 per c.c: soil and partially sterilised soil 1,650,000, ignited soil 1,500,000 and clay 2,450,000.4. These figures are constant for given material and organisms and are independent of the concentration of the suspension, the time of action, or whether the suspension contains cysts or active forms of the amoebae and flagellates investigated. Also the action is the same when the experiment is performed with a suspension of living or dead organisms.5. Experiments with the ciliate—Colpoda cucullus—show that coarse sand per gram retains 27,000 per c.c.; fine sand per gram 185,000 per c.c; soil and partially sterilised soil 280,000 per c.c; ignited soil 270,000 per c.c. and clay 450,000 per c.c.
The chemistry of the strength of wheat flour
Authors: Woodman Herbert Ernest 
Published: March 2009

It is well known that different flours vary enormously in respect of the size and shape of loaf they yield on baking. The factor which determines the quality of flour in this connection has been termed “strength” and the latter has been denned as “the capacity of flour for making large well-piled loaves”(1).Many views have been held from time to time regarding the explanation of flour strength from the chemical standpoint. The earliest view was that strength was determined by the gluten content of the flour, which by virtue of its tenacity was able to retain in the bread the carbon dioxide produced as a result of the activity of the yeast. Many cases, however, were investigated where flours possessing a high gluten content were not so strong as a flour with a low content of gluten. Furthermore, no accepted regularity has been found to exist between the strength of flours and the water-holding or gas retaining capacity of their glutens.
The determination of ammonia in soil
Authors: Matthews Donald J. 
Published: March 2009

Ammonia can be recovered from soil with an efficiency of 98·5 to 99·5 per cent, in six hours in the apparatus described.For most purposes it is sufficient to aerate the soil for three hours.Highly dunged glasshouse soils undergo partial decomposition in the cold with magnesia. In such cases the soil should be aerated with magnesia and strong sodium chloride solution for a definite time, say three hours.The complete recovery of added ammonia from a calcareous soil is difficult unless the soil is finely ground.
The inter-relationships of grazing method and stocking rate in the efficiency of pasture utilization by dairy cattle
Authors: McMeekan C. P. , Walshe M. J. 
Published: March 2009

1. A large-scale grazing management study comparing rotational grazing and continuous grazing with dairy cows at two stocking rates over four complete production seasons is described.2. The four treatments were: (i) controlled grazing, light stocking rate; (ii) controlled grazing, heavy stocking rate; (iii) uncontrolled grazing, light stocking rate; (iv) uncontrolled grazing, heavy stocking rate.Each treatment involved 40 cows for a first 2-year phase and 42 cows for the following 2 years. Each herd had a normal age distribution pattern and seven 2-year-old first lactation heifers (17% of total herd) were introduced each year to maintain this pattern.3. Stocking rate was the more important factor affecting the efficiency of pasture utilization as measured by per acre output of milk and butterfat. In general, high stocking was associated with higher outputs per acre despite lower yields per animal.4. Grazing method was of less importance. In general, controlled rotational grazing was superior to uncontrolled continuous grazing, both per animal and per acre, but the average influence even of these extremes of management was only half that of stocking rate.5. Significant interactions between stocking rate and grazing method existed. Under continuous grazing a point was reached where production per acre declined to the vanishing point with increased stocking rate due to excessive depression of per cow yield: this point was not reached under rotational grazing at the same high stocking levels.6. The results suggest that optimum stocking rate under rotational grazing occurs at a level some 5–10% higher than under continuous grazing. A depression of 10–12% in per cow yield, compared with more lenient grazing, corresponds with optimum stocking level irrespective of the grazing system. This estimate is suggested as a guide line in applying the principles involved.
Some effects of primary cultivations on crop yields in a four-course rotation
Authors: Barker M. G. 
Published: March 2009

A long-term experiment designed to study the effects on crop yields of different basic methods of cultivation used in the preparation of seedbeds is described and the results of the first completed cycle of 4 years are discussed. Four basic methods of cultivation were compared, namely, ploughing, rotary cultivating, cultivating and discing. Each one of these was done, early and late, for each crop in two four-course rotations which differed only in the cropping of 1 of the 4 years when potatoes were used in one case and a 1-year ley in the other. Each crop in the rotation (winter wheat, sugar beet, barley, ley or potatoes) was grown at two levels of fertilizer application and provision was made in the design of the experiment for two different weed control régimes. The soil was fairly easy to work, being of the Milton series of river gravels.As a result of the work described, the following conclusions have been drawn:1. Ploughing was the most consistent method of providing a satisfactory basis for the final seedbed preparation but in some circumstances other methods were equally good. On average, ploughing led to the highest yields and discing the lowest, with rotary cultivating second and cultivating third in order of merit.2. The yields of cereals grown after root crops were not dependent on the method of basic cultivation used.3. The effects of the cultivations on the yield of winter wheat after the ley appeared to be due to the extent to which the regrowth of rye-grass was controlled, the plough being most effective in this respect.
Studies of a Scottish drift soil. II
Authors: Ogg William Gammie , Hendrick James 
Published: March 2009

1. Craibstone soil—a glacial drift soil which has not undergone very profound weathering and is free from calcium carbonate—has a considerable absorptive power for ammonia from a solution of sulphate of ammonia.2. It was found possible to make a mechanical analysis of a large quantity of this soil without the use of acid and alkali, and although the separation into fractions was by no means perfect, a very fair comparison was obtained of the absorptive capacities of the different fractions.3. The absorptive power per unit weight of the fractions, as would be naturally expected, increases with the decrease in size of the particles, reaching a maximum in the case of “clay.”4. “Fine silt” and “silt” have also a high absorptive power. This may be partly due to the presence of organic matter, but allowing for that, these fractions have a high power of absorption.5. It was not the object of these experiments to draw any detailed conclusions as to the relation between surface and absorptive power, but it seems probable, from the results obtained, that the absorptive power is not determined by surface alone, and that the chemical composition of the fractions has an influence on the absorptive power.
Studies in soil cultivation. III. Measurements on the Rothamsted classical plots by means of dynamometer and plough.
Authors: Haines William B. , Keen Bernard A. 
Published: March 2009

Maps of soil resistance to ploughing have been drawn up from the dynamometer readings over several seasons for the Rothamsted classical plots, carrying wheat, barley and roots respectively.The conclusions as to the effect of manurial treatment are only of a general nature at the present stage of the work. Such differences are certainly small in comparison with the natural variations in the soil.In the case of the Broadbalk wheat plots the drawbar pull values have been shown to have a close relationship with the clay content of the soil and with certain aspects of the soil drainage.
Studies in Crop Variation VII. The Influence of Rainfall on the Yield of Barley at Rothamsted
Authors: Wishart J. , Mackenzie Winifred A. 
Published: March 2009

VI. SummaryThe conclusions of an earlier study of the yield of dressed grain from Hoos Field over the period 1852–1921 are recalled, and the method of conducting an examination of the influence of rainfall on the yield is described. The method yields a series of curves showing at any given period of the year the benefit or loss to the final yield in bushels per acre due to an additional inch of rain over the average at that period. Thirteen plots are considered, and the curves are found to fall roughly into groups corresponding to the system of manuring adopted. The main effects noted are these: (1) Excess of rain is beneficial to the barley crop for a short period in summer, and, in the case of certain plots, over the autumn and winter period. This is in contrast to the corresponding result for wheat on Broadbalk, where excess of rain was found to be beneficial only on a few plots and over a very limited period. (2) Rainfall over the six months when the barley is not in the ground is just as important as rainfall in spring and summer, and the time at which the rain falls in winter is important. Excess of rain in autumn benefits plots 1–A, 3–A and 7–2, and in winter continues to benefit 1–A and 3–A. (3) The curves for 2–O and 2–A are essentially different in character from those of the other plots, and point to the important effect of excess of winter rain in reducing the yield of the plots having phosphate but no alkali salts (i.e. no potash, soda, magnesia). (4) Excess of rain at time of sowing is harmful in all cases. (5) The curves of the “O” series (without nitrogen) are much flatter than those of the “A” series, which have a nitrogenous dressing in addition. (6) The indication of summer benefit is not inconsistent with the conclusions of Hooker that a cool summer is desirable for barley. (7) The farmyard manure plot 7–2 bears certain resemblances to the curve for the corresponding plot 2 b on Broadbalk.
Investigations into the Intensive System of Grassland Management.
Authors: Greenhill A. W. 
Published: March 2009

1. Herbage from pastures managed under the Intensive System of Grassland Management, and representing three to five weeks’ growth, from three centres in three seasons, was closely comparable with that obtained by other workers from “pasture cuts” at one- to three-weekly intervals from unmanured pastures, in respect of the chemical composition of its dry matter, which is, in fact, a concentrated feeding stuff of narrow nutritive ratio and low in fibre content.2. The nutritive ratio is somewhat wider in a dry than in a wet season, but the average fibre content is not markedly different.3. During the grazing season, drought or the early summer flush period produce some reduction in protein content and an increase in fibre content, with a recovery following the cessation of the drought or after the flush period respectively.
Nutritive value of lucerne. III. The composition, digestibility and nutritive value of lucerne hay, lucerne meal (English and American) and lucerne leaf meal (American)
Authors: Woodman H. E. , Eden A. 
Published: March 2009

In this paper, which is the third of a series dealing with the nutritive properties of the lucerne crop, an account is given of the results of an investigation into the composition, digestibility and nutritive value of lucerne hay, lucerne meal and lucerne leaf meal.Three samples of lucerne hay were dealt with, the first two having been made by baling direct from the field and the third by the usual procedure of filling into the stack. It is shown that by baling from the field, it is possible to conserve forage at a higher moisture content than would be considered safe when filling the material into a stack. In such circumstances, however, too tight a compression of the bales should be avoided, since if the process of partial drying-out during storage be retarded by over-compression, there is danger of extensive mould development and spoiling. It is advisable that the bales should be stored under good cover and in such a manner as to permit of free circulation of air between them. The hay from the bales was of much poorer quality than that made in the stack.
Developmental changes in beef steers as influenced by fattening, age and type of ration
Authors: Luitingh H. C. 
Published: March 2009

1. The effect of fattening, age and the ratio of concentrates to roughage in a ration on the development of beef steers was investigated. The specific purpose was to study developmental patterns during the short-term fattening of beef steers of different ages in order to ascertain to what extent beef steers improved in the proportions of the various body parts, offals, organs and tissues.2. The experimental material consisted of 104 beef steers of three age-groups, namely, ± 8, ± 20 and ± 32 months old, fed on rations differing in the ratio of concentrates to roughage and 36 control steers of the same age-groups, slaughtered at the start of the experiment.3. When the weights of the parts of the carcasses were expressed as a percentage of the carcass weight, it was found that with the exception of a few parts, the percentage which the parts constituted of the carcass remained remarkably constant in the various groups. The effect of age in both the fattened and unfattened groups was comparatively small, whilst the effect of fattening was of slightly greater magnitude. The effect of the ration concentration per se was negligible.4. The parts where fat was deposited formed a significantly (P < 0·01) larger percentage of the carcass of the fattened than of the unfattened steers (kidney and channel fat, thin flank and cod, brisket, plate and neck).5. The shoulder, chuck and buttock and rump, formed a significantly (P < 0·01) lower percentage of the carcasses of the fattened than of the unfattened steers.
The improvement of winter oats
Authors: Hunter H. 
Published: March 2009

The original object of the breeding investigations described above was to secure a new variety of oats exhibiting the resistance to winter conditions and the grain quality characteristic of Grey Winter, in combination, if possible, with straw of better standing power.The characters of the hybrids studied in the course of the investigations were accordingly resistance to winter conditions, standing power of the straw, quality of the grain, and the early growth habit, particularly in relation to these three features.
The action of viscogen (calcium saccharate) on milk and cream
Authors: Pyne G. T. 
Published: March 2009

The mechanism by which viscogen (calcium saccharate) brings about an increase in the viscosities of milk and cream has been investigated.The primary reaction appears to be the formation of a precipitate of insoluble (tri-calcium) phosphate. Considerable quantities of casein are carried down by the precipitate, and this co-precipitation of casein is probably the single factor which most influences the viscosity.Casein is not directly precipitated by viscogen, but the viscosity of its solutions is slightly increased as a result of their higher alkalinity due to this reagent. This action of viscogen is relatively unimportant in influencing the viscosity of milk or cream.
The availability of the potassium in some scottish soils
Authors: Stewart Robert 
Published: March 2009

(1) The solubility of the potash in 34 soil samples from 13 soils typical of large areas in the East of Scotland has been determined by the methods of chemical analysis using (a) hot concentrated hydrochloric acid, and (b) 1 per cent, citric acid solution, and the values obtained compared with the quantities of potash existing in the exchangeable form. The total mineral potash has been determined for six samples and Neubauer's method of analysis has been applied to 10 samples and again compared with the exchangeable potash.(2) The average value of the total mineral potash in the soils examined was 2·04 per cent., which indicates the presence of comparatively large reserves of potash in these soils. No relation was found to exist between the total potash, and the quantities soluble in hot concentrated hydrochloric acid.(3) The average value of the HCl-soluble potash was 0·50 per cent, and in the profile samples there was generally an increase in solubility with increase in depth of soil.
The Fertilising Value and Nitrifiability of Humic Materials Prepared from Coal (With Three Text-figures.)
Authors: Crowther E. M. , Brenchley Winifred E. 
Published: March 2009

Summary1. Humic acids and ammonium humates prepared by a patented process of gentle oxidation of coal were examined as fertilisers by laboratory nitrification experiments and pot-culture tests on four soils and by a number of field experiments on a range of soils and crops during a single season.2. In all tests the effects of ammonium humate could not be distinguished from those of ammonium sulphate of equal ammonium content. The nitrification tests and the pot cultures afforded some evidence of a slow production of nitrate or available nitrogen from the humic acid.3. In the field experiments as in the pots there was no clear evidence of any fertiliser value apart from that due to the ammonium present.
The ‘easily reducible’ manganese of soils
Authors: Dion H. G. , Mann P. J. G. , Heintze S. G. 
Published: March 2009

1. In studying the factors influencing the ‘easily reducible’ manganese in soils, results were obtained to indicate that the estimation is dependent on the pH of the system, the nature of the salt solution, the nature of the reducing agent and the time of contact, in addition to the amount and nature of the higher oxides of manganese present.2. Pyrolusite (MnO2) and a synthetic preparation of manganite hydroxide are ‘easily reducible’ oxides, while manganite (MnO(OH)) and naturally occurring hausmannite (Mn Mn2O4) are apparently ‘difficultly reducible’ forms.3. Since pyrolusite occurs in the easily reducible fraction, those deficient soils which contain only a small proportion of their manganese in the easily reducible form must contain the larger part in a form less reactive than pyrolusite.
Protein-bound iodine, erythrocytes and haemoglobin in the blood of beef steers and their relation to rate of gain
Authors: Luitingh H. C. 
Published: March 2009

The serum protein-bound iodine concentration in the blood of beef steers varied between animals and was not correlated with the daily gain during the fattening period. The data, however, are insufficient to arrive at a definite conclusion.The average erythrocyte counts of the blood were 7·86 (range: 5·89–8·75), 8·59 (range: 6·55–10·15), and 8·54 (range: 5·23–9·62) million per mm.3 for steers of 14, 26 and 38 months of age. The difference between the counts of the yearlings and that of the other age groups was statistically significant. The red cell fraction increased with live weight over the range 700–1230 lb. Although a significant (P < 0·01) correlation was found between the number of erythrocytes in the blood and the daily gain of the steers, the erythrocyte count cannot be employed to predict the possible gaining ability of single beef animals.The haemoglobin content of the blood was found to be 14·02 (range: 9·8–17·4) in the case of the yearlings, 14·68 (range: 11·8–18·5)and 14·61 (range: 7·95–16·85) g./100 ml. blood in the case of the 2-year-olds and 3-year-olds respectively. These differences between age groups were not significant.A correlation of 0·31 was found between the haemoglobin content and live weight of steers within the weight range of 600–1230 lb. The data suggest that for every 100% increase in weight, the haemoglobin in the blood increased by 17%. No correlation was found between the haemoglobin content and the rate of gain of the steers.