bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of soil type and depth on crop production
Authors: Reith J. W. S. , Inkson R. H. E. , Caldwell K. S. , Simpson W. E. , Ross J. A. M. 
Published: March 2009

SUMMARYTopsoils from eight different soil series were substituted for the local soil in three arrangements involving two depths of topsoil and either local or sand subsoils. A rotation of crops was grown with uniform annual N, P and K treatments for 24 years. A peaty soil produced the highest yields of grain, straw and grass, presumably because it released more N than the mineral soils, but an average yield of swedes. No mineral soil consistently produced higher yields of all crops and, although there were some significant differences, the variations in yield were generally relatively small. The deep topsoil consistently produced the highest yields. Topsoil with sand subsoil gave the lowest yields of grain, straw and swedes but not of grass.All the crops on the peaty soil had higher concentrations of P in the dry matter than those from the seven mineral soils. Crops and herbage on the Laurencekirk and Foud-land soils had consistently slightly higher P concentrations than those on the other five mineral soils. Compared with the amounts applied, the crops removed considerably more K but only 45–68% of the P. There were large differences in the proportion of the P residues extractable by acetic acid from the different soil series.The depth of topsoil was at least as important as soil type in determining yield, and the results support the use of soil depth as one of the main factors used in the Land Capability Classification for Agriculture.
The measurement of leaf colour in grasses
Authors: Hamill Madeline , Camlin M. S. 
Published: March 2009

SUMMARYA method of assessing colour of grass leaves was developed to distinguish between cultivars. Leaves from a representative population of 60 plants of each cultivar were measured. To eliminate subjective judgment a colour difference meter was used, giving tristimulus values X, Y and Z (approximating to red, green and blue respectively), from which the colour co-ordinates L, a and b of the Commission Internationale de L'Eclairage system were calculated.In a pilot study two visually distinguishable perennial ryegrass cultivars were easily separated (P <0·01) using the colour measurements. In a further examination comparing 23 cultivars, 68% of all possible cultivar pairs were separated (P <0·01).
The value of potato peelings in the nutrition of the bacon pig
Authors: Woodman H. E. , Evans R. E. 
Published: March 2009

Mechanical peeling of potatoes removes an exceedingly thin skin that is notably richer in ether extract, fibre and lime, but much poorer in N-free extractives, than the thicker parings obtained by ordinary hand peeling. The latter, in respect of their general composition, do not differ to any marked extent from whole potatoes.The results of digestion trials with pigs have shown that potato peelings, after cooking, are highly digestible when included in the rations of bacon pigs. The N-free extractives, which form about 80% of the dry matter of the hand peelings, have a digestion coefficient of 96·2%. An allowance of 5 lb. of such peelings supplies as much digestible organic matter as 4 lb. of whole potatoes, and it is concluded that 1 lb. of barley meal in the rations of bacon pigs may be replaced by 4 lb. of potatoes or by 5 lb. of potato peelings. Both the potatoes and the potato peelings should be cooked before feeding.In conclusion, the writers take this opportunity of expressing their thanks to Messrs V. Thurlbourn and C. Bendall, in whose experienced hands the care of the experimental animals was placed during the digestion trials.
The effect of Beckmann's treatment by sodium hydroxide on the digestibility and feeding value of barley straw for horses
Authors: Williamson Grahame 
Published: March 2009

The digestibility coefficients of old barley straw fed with a basal ration of oats, bran and maize to two adult horses and of the same straw after treatment by Beckmann's method were ascertained. The coefficients of the nitrogen-free extractives and the crude fibre of the untreated straw were 33·23 and 38·24 respectively and of the treated straw 54·14 and 63·71. There was a reduction in the digestibility of the small quantity of protein and fat.Taking into account the 14·5% of dry matter lost during treatment, the starch equivalent value of the treated material was somewhat higher than that of poor quality meadow hay.The digestibility coefficients were considerably lower for an immature horse previously maintained entirely on fresh grass.
The course and magnitude of water stress in Lolium perenne and Dactylis glomerata
Authors: Jackson D. K. 
Published: March 2009

SUMMARYSimulated swards of Dactylis glomerata (var. S.37) and Lolium perenne (var. S.23) were grown in large lysimeters or vertical pipes of 15 cm diameter, both sufficiently deep to allow largely unrestricted root development.Rainfall was excluded, and the effect of a drying cycle on the plant water balance was compared with irrigated controls in a sequence of sampling harvests at increasing soil water deficits.Leaf water potential (ΨL) fell during the day, both in treatments and controls, to levels which might be expected to reduce extension growth and, frequently, stomatal diffusion. Rapid recovery occurred in the evening to levels which might allow normal functioning of growth processes not dependent on sunlight. Defoliation reduced plant stress and stomatal restriction.The amelioration of plant water stress appeared to require a reduction in atmospheric evaporative demand, and irrigation had relatively little effect. The possibility is discussed that the major benefits of irrigation are other than through the relief of water stress within the plant. The significance of this is considered in relation to conventional irrigation techniques.The leaf water status was more sensitive to drought, transpiration was reduced more, and the root system extended more slowly in Dactylis than in Lolium. Consequently, the onset of permanent wilting due to exhaustion of water from the profile was delayed compared with Lolium. It is deduced that this characteristic might enhance the survival of Dactylis in prolonged drought, but prove disadvantageous in terms of growth during short droughts, when reduced stomatal opening might limit CO2 uptake. This would not be an impediment, however, if investigations suggesting that partial closure has a minor effect on CO2 uptake compared with that on transpiration were to be confirmed.
Investigations on the root-nodule bacteria of leguminous plants: XXI. The growth of the root-nodule organisms and inoculated peas at low temperatures
Authors: Vartiovaara Unto 
Published: March 2009

The present paper records some investigations on the growth of the clover- and pea-nodule organisms (Rhizobium trifolii Dangeard and Rh. leguminosarum Frank), and the nitrogen fixation of the pea, at low temperatures. Growth of the bacteria was studied with pure culture experiments in large flasks, in which the bacteria were grown on a solid gelatine medium. The amount of nitrogen in the bacterial mass thus obtained was used as the basis of comparison. The fixation of nitrogen by peas was studied with a pot-culture experiment in a relatively cold greenhouse. Inoculated plants were grown in quartz sand, and were supplied at an early stage with mineral nitrogen either as Ca(NO3)2 or (NH4)2SO4. The plants were harvested after flowering and analysed. The main results of these experiments were the following:(1) Pure-culture experiments with five strains of clover-nodule bacteria and four strains of pea-nodule bacteria showed that at 6–13° C. the strains imported from more temperate climates grew distinctly less well than did the northern European strains. Even between the Swedish and Finnish strains there were clear differences: the latter formed the more bacterial matter in the cold. It may be appropriate to consider such differences when selecting cultures for inoculating leguminous crops.(2) In the pot-culture experiment, the application of mineral nitrogen (30 mg. N per plant) to inoculated peas kept at relatively low temperatures had very little effect on the amount of dry matter produced. The slightness of this effect was similar to what has been previously observed in experiments at more favourable temperatures. Nitrogenous fertilization slightly lowered the amounts and percentages of total N present as protein and amino nitrogen, in the crop; but nitrate application somewhat increased the nitrate content of the crop. Hence, it may be concluded that, even under these low-temperature conditions, the application of artificial nitrogen has not had a favourable effect on the size or quality of the crop.
An accurate wet-combustion method for the determination of carbon in soils
Authors: Alper Pauline 
Published: March 2009

1. Inaccurate results previously obtained with wet-combustion methods for the determination of carbon in soils have probably been due to: (a) incomplete oxidation of carbon; (b) incomplete absorption of carbon dioxide. The method described herein ensures complete oxidation and complete absorption. The oxidizing agent employed consists of a mixture of sulphuric acid and potassium bichromate; the absorption takes place in a closed system.2. When highly accurate results are required, a combustion tube is a necessary adjunct to the wet-combustion method, as appreciable amounts of carbon escape complete oxidation in reaction flask.3. The soil should be moistened with water before adding the oxidizing mixture, to avoid the formation of complexes, which may protect part of the carbon from oxidation by the acid.4. Within limits, the concentrations of sulphuric acid and potassium bichromate do not affect the results.5. While it is necessary to use catalysts (selenium and potassium sulphate) for the complete oxidation of the resistant carbon of coal, catalysts were found to be unnecessary for the determination of carbon in soils.6. For soils rich in chloride, it is necessary to absorb the chlorine evolved by means of sodium bisulphite solution.
On the influence of protein on the fattening of fowls
Authors: Halnan E. T. 
Published: March 2009

1. The principal change in the composition of adult fowls during fattening is an increase in the fat content of the body, the protein increase being subordinate in amount.2. Within the limits studied, the efficiency of conversion of food energy to carcase energy is not affected by variation in the protein content of the ration.3. A food mixture consisting of 5% dried skim milk of 95% Sussex ground oats proved as efficient for fattening fowls as a food mixture consisting of 20% dried skim milk, and 80% Sussex ground oats.4. The food mixtures used gave satisfactory results in fattening when used in pellet form in a dry state.
The ignition at low temperatures of the organic matter in soils
Authors: Hosking J. S. 
Published: March 2009

The low temperature ignition of soil organic matter has been investigated for temperatures ranging from 100 to 500° C.Appreciable losses are found to occur below 100° C.; up to 200° C. heating results essentially in the distillation of volatile constituents, while between this temperature and 300° C. destructive distillation is the major reaction. These reactions are responsible for the removal of 85% of the soil organic matter.By 300° C. the greater part of the residual organic matter consists of carbonaceous material, and the final reaction is simple ignition of this material.Two hours’ heating of the soil at 450° C. or about half an hour at 500° C. are recommended for the removal of 99% of the soil organic matter.
The chemical evaluation of pyrethrum flowers (Chrysanthemum cinerariaefolium): A comparison of several methods
Authors: Martin J. T. 
Published: March 2009

1. Comparative analyses of pyrethrum flowers have been carried out by the methods of Tattersfield, Seil, Ripert, Haller & Acree and Wilcoxon.2. The methods were of value in indicating the relative richness in pyrethrins of the samples tested, but discrepancies were seen in the absolute values of the pyrethrins I and II recorded. Under present conditions and until a standard method of analysis is agreed upon, it would appear requisite to state the method employed in the evaluation of the flowers.3. The Wilcoxon method has given higher figures for the pyrethrin I content than the Seil method. The degree of divergence between the results depended upon the richness of the flowers, and upon the excess of acid used in distilling the volatile acid in the Seil method. The relationship between the amount of the pyrethrin I acid present and the titration recorded in the Wilcoxon method was not a linear one.4. The question of the solvent to be used for the initial extraction of the flowers has been briefly discussed.
Sheep nutrition: I. Measurements of the appetites of sheep on typical winter rations, together with a critical study of the sheep-feeding standards
Authors: Woodman H. E. , Evans R. E. , Eden A. 
Published: March 2009

Feeding trials with sheep, subsisting out-of-doors on typical winter rations of known dry-matter and starch-equivalent content, have been carried out during the winters of 1933–4, 1934–5 and 1935–6. Records have been kept over these periods of the live-weights of the animals and their daily consumption of dry matter and starch equivalent.It has been found that the standards of appetite, in terms of lb. dry matter, proposed by Prof. T. B. Wood are uniformly too high, a result in harmony with the findings of Prof. J. A. S. Watson and co-workers at Oxford. It is suggested that Prof. Wood's values should be multiplied throughout by the factor 0·85 in order to obtain reasonable measures of the appetites of sheep at different live-weights.The data from the feeding trials have been used in an attempt to decide between the old and the recently proposed standards for the maintenance starch-equivalent requirement of the 100 lb. sheep, namely, 0·74 and 1·26 lb. of starch equivalent per day. The results point to the reliability of the higher figure, and it is shown that the results of recent work on the energy metabolism of sheep are in harmony with this conclusion.A table embodying a revision of Prof. Wood's feeding standards for sheep is included in the paper.
The time of cutting hay, and the losses entailed during haymaking
Authors: Watson S. J. , Ferguson W. S. , Horton E. A. 
Published: March 2009

Experiments have been carried out from 1930 to 1935, to investigate the composition, digestibility and yield of meadow hay cut at a normal time, and also of hay cut some 3–5 weeks earlier. Due consideration has been given to the “aftermath” growth occurring on the areas cut for the early hay between the times of cutting of the early and ordinary hay.As was expected, the early hay, being less mature, was of better composition and digestibility than the ordinary hay. The average crude protein contents were 12·2 and 7·9 per cent of the dry matter respectively.The yield data, average of 5 years, are summarized below, stated as lb. per acre, the early hay values including the aftermath yields.
The solubility of soil phosphorus and other phosphorus compounds in sodium hydroxide solutions
Authors: Williams Rice 
Published: March 2009

1. The solubility of the phosphorus of soils and of other phosphatic materials in solutions of sodium hydroxide has been investigated. A method for the extraction and determination of the soluble phosphorus is described.2. With acid soils, especially when the exchangeable calcium has been removed by leaching, an approximately constant amount of phosphorus is extracted by sodium hydroxide solution of strengths from 2 per cent to 20 per cent. The soda-soluble fraction amounts to 90 per cent of the total phosphorus.3. Soils containing free calcium carbonate vary in the solubility of their phosphorus in sodium hydroxide solutions. Some behave similarly to acid soils, whilst others show only a small fraction of their total phosphorus to be soda-soluble. The extraction is complicated by the presence of calcium carbonate, which can precipitate from solution compounds which, in its absence, are soda-soluble.
Experimental methods with cotton: I. The design of plots for variety trials
Authors: MacDonald D. , Fielding W. L. , Ruston D. F. 
Published: March 2009

1. The results of three uniformity trials with a U4 cotton at Barberton are reported. Two of these trials, carried out in a dry year, gave yields in the region of 400 lb. seed cotton per acre; the third, in a wet year, yielded over 1100 lb. per acre.2. Results from the three experiments agreed closely in essential details regarding size and shape of plots.3. In all three cases the percentage standard error per plot decreased rapidly as the plot was lengthened, but tended to increase slightly as the width of the plot was increased.4. The standard error increased as the block size was increased by the addition of more plots, indicating the desirability of keeping the number of strains in a variety trial as low as possible.5. With plots of the same shape the smallest plots were the most efficient, while with plots of the same size the efficiency increased as the plot shape became longer and narrower.6. Two fertility contour maps are given, which illustrate a general patchiness in yield common to cotton crops in the Barberton district.7. Details of the types of plot used at Barberton are given, together with the reasons for their adoption.
Lucerne-derived flavour in sheep meat as affected by season and duration of grazing
Authors: Park R. J. , Ford Anne , Minson D. J. , Baxter R. I. 
Published: March 2009

SUMMARYMerino wether lambs and yearling sheep grazed irrigated lucerne or grass pastures in the period immediately before slaughter. Some of the sheep grazed continuously on the lucerne or grass for up to 6 months, while others grazed grass and then lucerne in the 4 weeks immediately before slaughter, over this same period. A laboratory taste panel compared the flavour of the meat from the grass and lucerne-fed sheep.The intensity of the flavour characteristic of cooked meat from lucerne-fed lambs or sheep was found to increase in intensity with increasing length of time of grazing the legume. In addition, both 4-week and continuous-lucerne grazing treatments exhibited significant seasonal effects, in which the intensity of the lucerne-derived taint was found to vary throughout the year, with a maximum intensity appearing when lucerne was grazed in the cooler months.
Red blood cell concentrations of reduced glutathione and potassium as biochemical markers of wool growth in Merino sheep
Authors: Hopkins G. J. , Roberts J. , Evans J. V. 
Published: March 2009

SUMMARYWool growth rates were estimated in Merino ewes differing in their red blood cell concentrations of reduced glutathione ([GSHRBC]). Over a 42-day wool growth period, sheep with low [GSHRBC] maintained significantly higher rates of wool growth. Red blood cell concentrations of K+, ([K+RBC]), [GSHRBC] and estimated gene frequencies for the low [GSHRBC] and high [K+RBC] genes were determined in flocks of Merino ewes bred for high or low clean fleece weight. The high fleece weight flock had a significantly lower [GSHRBC] and higher gene frequency for the low [GSHRBC] allele than the low fleece weight flock. The high fleece weight flock also had a significantly higher [K+RBC] and a higher gene frequency for the high [K+RBC] allele than did the low fleece weight flock.
The principles of orthogonality and confounding in replicated experiments. (With Seven Text-figures.)
Authors: Yates F. 
Published: March 2009

VIII. SummaryThe principle of orthogonality in replicated experiments is discussed and the dangers of non-orthogonality emphasised. The modifications necessary in the ordinary procedure of the analysis of variance when applied to non-orthogonal data are developed, attention being paid to the shorter methods, applicable in certain cases, by which the heavy labour of computation necessary in the general method of fitting constants may be avoided.Certain modifications in the design of replicated experiments, usually designated by the term confounding, are explained. The different types of confounding are discussed, together with their uses, and the appropriate methods of analysis are set out. The methods are applied to the analysis of an experiment on sugar beet (where a previous incorrect analysis is corrected) and an experiment on potatoes.
The nature of the calcium and phosphorus combination in the excreta of the non-laying pullet
Authors: Knowles Frank , Watkin J. E. , Hendry F. W. F. 
Published: March 2009

The results discussed in this paper are based on the weights and composition of the excrements of eight pullets, fed for the periods stated on three rations, which differed only in the amounts of calcium and phosphorus supplied in various combinations. The total amounts of calcium and phosphorus supplied daily were approximately the same in all cases.The birds were 5 months old White Wyandottes, and increased considerably in weight during the experimental period. No eggs were laid, but Pullet No. 2 died of prolapsus of the oviduct, and was found to have seven nearly full-sized yolks and one unshelled egg in the oviduct.
Soil Formation in Southern Nigeria. (The “Ilepa” Profile.)
Authors: Doyne H. C. , Watson W. A. 
Published: March 2009

Summary1. The typical profile of south-western Nigeria formed over acid igneous rocks under alternating conditions of percolation and evaporation is described. The profile being (a) brown sandy soil, (b) concretion layer, (c) red clay, (d) mottled red and white clay, (e) whitish clay, (f) rotting rock. Acidity increases with depth.2. Analyses of the concretion layer show that it consists chiefly of silica (quartz), ferric oxide, and occasionally some manganese. Alumina does not occur to a large extent.3. From studies of the mobility of the iron and soluble salts throughout the profile it is suggested that the profile is developed by a rise of an iron sol which is deposited on a layer of quartz to form the concretions.4. The Yoruba name “Il***pa” has been adopted by the authors for describing such a profile.
The significance of certain “single value” soil constants
Authors: Russell E. W. 
Published: March 2009

SummaryThe conclusions that have been arrived at from the foregoing statistical examination of the available data on the physical properties of the Natal soils used by Coutts are:(1) The base exchange capacity of the soil, as measured by Schofield's potassium phosphate buffer method, appears to be of predominant importance for predicting several of the soil properties, as for example the sticky point and the moisture content at 50 per cent. relative humidity. On the other hand, the clay content seems to be of quite minor importance in predicting these soil properties.(2) The information from the data supplied by the Keen-Raczkowski box indicates thatω, the weight of water held per gram of soil in the box is very closely correlated with the base exchange capacity of the soil, while the swelling and pore-space parameters are more complex. The swellingυseems to be dependent on the base exchange capacity of the soil and a term probably representing the structure of the soil, while the pore spacepseems to be dependent on the clay content and a soil structure term. By choosing an appropriate definition of the pore space practically all the structure information given by the swelling parameters is contained in it.