bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental methods with cotton. III. Sulphuric acid treatment of cotton seed, and its effects on germination, development and yield
Authors: Macdonald D. , Fielding W. L. , Ruston D. F. 
Published: March 2009

1. For experimental purposes the treatment of cotton seed with sulphuric acid, prior to planting, has always been the custom at Barberton. In view of the doubts about the benefits of this treatment which were expressed by Christidis (1936), experiments were carried out at Barberton in the 1938–9 and 1939–40 seasons, to provide concrete proof, if possible, of the advantages which it was believed resulted from it.2. A series of stand counts made soon after germination revealed definite benefits with acid treatment, in all experiments in both seasons. The seedlings emerged considerably earlier than those from untreated seeds, and the stands recorded at the final counts revealed a significant advantage for acid-treated seed, throughout the experiments. The second season's experiments gave a greater advantage for acid treating when meteorological conditions were bad than when they were good, but the advantage even with ideal weather was still significant. The benefit of acid treatment was shown to be greater, too, with poor samples of seed than with good, and with the smaller seed rate than with the greater.
Experimental methods with cotton. IV. A study of the effects of gap-filling on the development and yield of cotton plants in poor stands of hand planted cotton
Authors: Macdonald D. , Fielding W. L. , Ruston D. F. 
Published: March 2009

1. Experience raised doubts as to the usefulness of filling gaps in bad stands of cotton at Barberton and experiments were conducted in two seasons to measure its effectiveness. The experiments gave clear-cut results.2. Randomized gaps ranging from 20 to 40% of the stand were filled and left open for comparison, the filling being done 13 and 19 days after planting.3. Any reduction in stand, though reducing yield per acre, led to large and significant increases in yield per plant, even when the spacing was 3 by 3 ft., wider than that normally used on the Station.4. Replanting the gaps in a bad stand did not lead to any increase in yield per acre; there were, in fact, indications that this practice actually reduced yield per acre, the refills preventing plants of the original sowing from benefiting fully from the extra space available to them in a bad stand.5. The general conclusion is that no useful purpose is served by refilling the gaps in poor stands of cotton with up to 40% of gaps.
The manufacture and storage of cereal feeding-stuffs with incorporated non-protein nitrogen compounds
Authors: Snow D. , Smith J. A. B. , Wright N. C. 
Published: March 2009

1. Losses of incorporated non-protein nitrogen compounds from stored cubes have been determined. The loss of incorporated urea was very small provided moulding did not occur. The loss of incorporated ammonium bicarbonate was large, amounting in all to some 50–60%.2. The effects of the size of the cubes and of the nature of the container on nitrogen losses are discussed.
Investigations into the Intensive System of Grassland Management. By the Agricultural Research Staff of Imperial Chemical Industries, Limited. II. The Mineral Content of Intensively Treated Pasture and a Relationship Between the Nitrogen and Phosphorus Contents.
Authors: Greenhill A. W. , Page H. J. 
Published: March 2009

1. The mineral content of pastures farmed under the Intensive System of Grassland Management, and representing three to five weeks'growth, from three centres in two seasons, is reported.2. The lime content fluctuated considerably during the season, but the fluctuations showed no definite seasonal trend. The average seasonal content was practically identical in all cases.3. The phosphoric acid content showed a definite seasonal variation, falling during drought or the early summer flush period and recovering again after the drought or flush period respectively. The phosphoric acid showed consistently a very highly significant positive correlation with the nitrogen content of the herbage. The bearing of this correlation on the metabolism of the plant and on the phosphatic and nitrogenous manuring of pastures is discussed.
Effect of applying nitrogen to cereals in the spring or at ear emergence
Authors: Thorne Gillian N. 
Published: March 2009

Nitrogen applied at ear emergence to winter wheat or spring barley grown in pots with various levels of basal nitrogen fertilizer, increased grain and total dry weight much less than similar amounts of nitrogen applied in March or April. No nitrogen was absorbed after ear emergence from unfertilized soil, or from the early application, and at maturity equal amounts of nitrogen had been absorbed from early and late applications.Early nitrogen increased final ear number by increasing the number at emergence and also increased grain size. Late nitrogen had negligible effect on yield of ears present when it was applied and caused the production of new shoots with small ears. Nitrogen applied at both times increased leaf area duration after ear emergence similarly; early nitrogen by increasing area at ear emergence and late nitrogen by delaying senescence of existing shoots and causing production of new shoots. The efficiency in grain production of the leaf area present after ear emergence was less with late than with early nitrogen, mainly because of the low efficiency of the shoots produced after ear emergence.These results differed from those of field experiments in which early and late nitrogen usually increased grain yield similarly, probably because in the field there were no late unproductive tillers and all the late nitrogen was utilized in increasing grain yield of existing shoots. Another difference was that nitrogen uptake from soil in the field continued until maturity.
The Chemical Analysis of Clays, with Special Reference to clay Fractions of Soils
Authors: Groves Ruby C. 
Published: March 2009

1. Comparisons are made of the results obtained in the analysis of clays, especially of clay fractions separated from soils, by the standard sodium carbonate fusion method and by attack by means of mixed acids. Provided certain precautions are taken, in the latter case, the percentages of silica obtained are shown to be comparable with those given by the fusion method.2. A possible disadvantage of the acid method is that the attack of the clay is not invariably successful, but treatment of the silica with hydrofluoric acid provides a convenient and reliable means of detecting those cases in which failure occurs. Such clays must be decomposed by fusion with sodium carbonate.
Methods of Experimentation in Animal Nutrition
Authors: Dunlop George 
Published: March 2009

The unsatisfactory nature of the methods adopted in feeding experiments at Animal Nutrition Research Institutes has been shown to be due to the neglect of the worker to control variable factors, other than those being investigated, which affect the growth rate of his animals.It has been proved that age, sex (females and castrated males), condition and previous growth rate have no effect on the rate of live-weight increase of swine in the Cambridge University herd, and the basis on which animals are allotted to groups to ensure homogeneity is fallacious.
A rapid electrometric method for measuring “lime requirements” of soils
Authors: Hardy F. , Lewis A. H. 
Published: March 2009

1. A method for the rapid determination of lime requirements in laboratories equipped with the quinhydrone electrode is described. (10 gm. of soil are mixed in a small wide-mouthed bottle with 40 c.c. of neutral 0·2 M CaCl2 solution. The mixture is then titrated with 0·03 N lime-water in successive portions of 5 c.c, with three minutes' shaking between each addition. The pH value of the mixture is determined after each addition, and the titration continued until the reaction has passed pH 7·0. The results are plotted, and the exact volume of limewater needed to give a final reaction of pH 7·0 is estimated from the graph.)2. The method is compared with the Hutchinson-MacLennan method for a series of soils of different textures and different initial exchange reactions. It appears to yield more reliable results; it is less tedious; it is very rapid, and results obtained thereby can readily be reproduced.
On the influence of the carbon: nitrogen ratios of organic material on the mineralisation of nitrogen
Authors: Jensen H. L. 
Published: March 2009

Organic materials with a C: N ratio ranging from about 85: 1 to about 10: 1 were submitted to nitrification tests in an acid and in an alkaline soil during a period of 6 months. In the acid soil only pea pod meal, with a C: N ratio of 13·3: 1 showed an increase in inorganic N over control; in the alkaline soil the limit above which no nitrification will occur within a period of 6 months was at C: N = 26: 1; below this limit the rate of nitrification increased rapidly with decreasing C: N ratio. Unnitrified N was left behind in a quantity corresponding to 1·5–2·2 per cent, of the original material, the percentage being higher in the case of materials rich in N.All the materials tended to increase the content of “a-humus” in the soil, though not to the same extent or in the same manner. More “a-humus” was produced in the alkaline than in the acid soil, except in the case of farmyard manure. Straw, sweet clover, lupin and farmyard manure apparently acted both through their lignin content and through the synthesising action of microorganisms, since they increased the amounts of both N and methoxyl in humus. Mycelium of Polyporus contains a fraction possessing the properties of “humic acid,” rich in N, but devoid of methoxyl, which persists in the soil.
The properties of heavy alkaline soils containing different exchangeable bases
Authors: Joseph A. F. , Oakley H. B. 
Published: March 2009

1. The nature of the replaceable base in a clay or soil exerts a profound effect on the physical properties. Clay-like properties are exhibited most strongly in the case of lithium, sodium, and magnesium.2. The proportion of fine material in a soil (i.e. that which remains in suspension in a column 10 cm. high after 14 days) cannot be correlated with other physical properties. Thus a soil of which over 50 per cent, was dispersed to this extent was the least plastic of those examined.3. A comparison of sodium, potassium, and calcium clays and soil showed that potassium resembles sodium in its chemical relationships as indicated by base exchange, but is very different from it in such physical properties as plasticity and permeability.4. Using mixtures of one-half normal chlorides of two bases, calcium and potassium are absorbed in equivalent amount while the sodium absorbed is only one-sixth of the amount of either of the other two.
Experiments on the effects of phosphate applied to a Buganda soil: II. Field experiments on the response curve to triple superphosphate
Authors: Le Mare P. H. 
Published: March 2009

SUMMARYA sigmoid curve for response to superphosphate has been demonstrated in field experiments in a Buganda red clay loam. There was evidence that the curve was abnormal; with small dressings of triple superphosphate yield of cotton and beans, and their phosphorus uptake, were decreased, but these characters were increased with larger dressings. Heavy dressings, from 4 to 16 cwt triple superphosphate, increased yield of these crops. Similar effects were observed with maize during growth and maturity was advanced, but final yield of grain was not affected by applied phosphate. The suggestion is made that in a long growing period the maize was able to absorb adequate phosphorus, even though the phosphate intensity in the soil was low, to achieve its potential yield.
The effects of potassium and magnesium fertilizers on yield and composition of successive crops of ryegrass, clover, sugar beet, potatoes, kale and barley on sandy soil at Woburn
Authors: Bolton J. , Penny A. 
Published: March 2009

SUMMARYIn an 8-year field experiment, potassium sulphate and to a lesser extent magnesium sulphate increased yields of all crops both when applied alone and together. Although K/Mg interactions did not affect yields they considerably affected the ratio of concentrations of these elements in the dry matter of the crops. Sodium chloride increased yields of kale but not of barley harvested at ear-emergence.Percentage yield response to potasium followed the orderPotatoes (218%) < clover = barley < sugar beet < kato; < ryegress (17%).Magnesium increased yields from 3 to 10%, most with potatoes.Changes in exchangeable magnesium in the soil reflected differences between applied magnesium and crop uptakes. Changes in exchangeable potassium were less than expected, probably because non-exchangeable potassium was released on plots without added potassium and ‘fixed’ in non-exchangeable forms on plots where much fertilizer potassium had been given.Increase in the incidence of magnesium deficiency symptoms reported recently in South. East England are attributed to the local liming materials containing only small amounts of magnesium and to less F.V.M being applied to crops than previously.
The determination of exchangeable bases in soils, Magnesium, potassium and total bases
Authors: Williams Rice 
Published: March 2009

(1) Exchangeable magnesium and potassium can be determined in carbonate-free soils by the use of 0.5 N acetic acid as a leaching agent.(2) A method is described for the determination of the total exchangeable bases present as acetates in the leachings.(3) The results obtained by this method differ from those obtained by summation of separate determinations by an amount equivalent to the sulphates and chlorides present.(4) It is suggested that the total exchangeable bases by the proposed method gives a truer measure of the exchangeable bases than methods in which bases present as sulphates and chlorides are also reckoned in.
A note on the determination of soil organic matter: A wet combustion method
Authors: Hardy F. 
Published: March 2009

(1) A gasometric method for the determination of organic carbon in soils by the use of sulphuric-chromic acid mixtures at 100° C., as suggested by Watts in 1902, is described, and recommended for use in routine soil analysis.(2) The method is compared with the Kjeldahl procedure recently introduced by Robinson, McLean and Williams, and is found to give results which are generally similar, though numerically slightly lower.(3) The wet combustion method is somewhat simpler than the Kjeldahl method, but it has the disadvantage that nitrogen determinations cannot be made simultaneously, so that its usefulness in studies on soil organic matter is decidedly less.
Statistical research on the fate of dietary mineral elements in dry and lactating cows III. Phosphorus
Authors: Lomba F. , Paquay R. , Bienfet V. , Lousse A. 
Published: March 2009

SUMMARYStatistical analyses were carried out on the data obtained under very strict conditions in metabolism stalls with 41 different rations fed to 127 adult non-pregnant dry cows and with 14 other different rations fed to 35 adult non-pregnant lactating cows that had calved 2–6 months earlier and whose daily milk production ranged from 11 to 20 kg.The correlations between faecal and urinary phosphorus losses, phosphorus in milk, digestible phosphorus and phosphorus balance and the other nutritive factors of the 55 above-mentioned experimental diets have been calculated.In dry and lactating cows, with very variable intakes of phosphorus, phosphorus faecal and urinary losses show very wide variations and may be important. They are not influenced by phosphorus intake, and are related, among the many other nutritional factors we analysed only to ingested water and to a lesser extent to the nitrogen of the diet.The phosphorus balance is thus also very much variable and not really related to the composition of the ration.This low influence of the diet on the apparent fate of phosphorus can be explained by the interference of unpredictable but certainly quite variable endogenous phosphorus excretion, which is also probably responsible for the effect we found of individual factors and of the previous nutritional status.In the lactating cows, the phosphorus requirements for milk production influence the utilization of phosphorus since a significant correlation exists between phosphorus secreted in the milk and urinary phosphorus.In our experimental conditions, the Ca: P ratio does not seem to influence the fate of dietary calcium and phosphorus.
Seasonal changes in the composition and mineral content of the body of hill ewes
Authors: Field A. C. , Suttle N. F. , Gunn R. G. 
Published: March 2009

SUMMARYGroups of ewes kept under hill conditions were killed at intervals during October to July 1965–66. Supplementary feed was given between February and May. The carcasses were divided into soft tissue, uterus and its contents and skeletal fractions. Each fraction was dissolved in HNO3 and its fat and mineral content measured. The sheep were heavier in November and lighter in May during lactation than at other times. The content of fat in the body fell progressively from October to May and then increased; initially fat was withdrawn only from the soft tissues but by April and May the fat contents of both skeleton and soft tissues were exceedingly low. The weight of fatfree soft tissue remained relatively constant but was heaviest in July. Fat-free skeleton fraction was lighter in January than in April.The contents of the predominantly intracellular ions, P, Mg and K in the soft tissue fell between November and January, remained constant between January and May and then increased. There was an increase in Na towards the end of pregnancy followed by a marked fall after parturition. The contents of Ca and P in the skeleton fell between November and January and during lactation between April and July. There was a marked increase between February and April when supplementary feeding was given. Evidence that Mg was selectively removed from the skeleton was obtained in November and January, two sheep having Ca:Mg ratios in skeleton greater than 100. Na and K contents of the skeleton were greatest at the end of pregnancy in April. For the lambs between 6 and 23 kg live weight, each kg of live-weight gain contained 8·8 g Ca, 5·0 g P, 0·27 g Mg, 0·83 g Na and 1·85 g K.
Haemoglobin type and blood potassium and sodium concentrations in Sudan desert sheep
Authors: Khattab A. G. H. 
Published: March 2009

SummaryThe incidence and distribution of haemoglobin types and potassium and sodium concentrations in whole blood of 411 Sudan Desert sheep and 11 Merino sheep were determined. Haemoglobin types were distinguished by electrophoresis in starch gel and blood potassium and sodium levels by flame photometry.Of the 411 animals examined, 396 possessed haemoglobin B in the homozygous state while only 15 possessed haemoglobin AB. The homozygous AA haemoglobin was not detected. No bimodality was found in whole blood potassium and sodium levels and the distributions were normal.
Biochemistry of water-logged soils: Part II. The presence of a deaminase in water-logged soils and its rôle in the production of ammonia
Authors: Subrahmanyan V. 
Published: March 2009

(1) The ammonia formed in water-logged soils was present mostly in the soil sediment. The surface water contained only a very small portion of the total amount produced.(2) Added ammonia was in a similar manner retained mostly in the soil itself. It could not be leached out by extraction with water nor volatilised with increase of temperature. There is evidence to show that the ammonia exists in the soil as an exchangeable base.(3) On allowing the soils to dry out the ammonia disappeared rapidly and corresponding amounts of nitrates were formed. Very little ammonia was lost by volatilisation.(4) The production of ammonia took place even in presence of volatile antiseptics. The reaction was shown to be brought about by a deaminase.(5) Studies with a number of proteins and ammo acids showed that only very simple amino compounds (glycine aspartic acid and asparagine) were deaminised. Witte's peptone, which contains amino acids, was also attacked.(6) An active preparation of enzyme was extracted from the soil with an aqueous solution of glycerin saturated with toluene.(7) Significant deaminising action was shown by the enzymes from cultures of the mixed microflora of the soils.(8) By acting on amino bodies that are otherwise resistant to biological action the deaminase probably helps to release readily available plant food. Its action should be of great importance in tropical swamp soils.
Studies onBacillus amylobacter, A. M. et Bredemann
Authors: Cunningham Andrew , Jenkins Hermima 
Published: March 2009

(1) An aerobic coccus has been obtained from cultures of the motile butyric acid bacillus under conditions which exclude the possibility of contamination.(2) Descriptions of the coccus and the bacillus are given.(3) The coccus does not fix nitrogen in soil extract containing dextrose.
Studies in mineral metabolism: V. Composition of bovine blood on phosphorus deficient pasture
Authors: Malan A. I. , Green H. H. , du Toit P. J. 
Published: March 2009

Data are recorded concerning the phosphorus partition of the blood of cattle grazing over phosphorus deficient pasture of the Union of South Africa. The outstanding characteristic is low inorganic phosphorus, with a correlated reduction in total phosphorus.When a small ration of bone meal is given to the cattle, comparatively normal figures are shown. Heifers approaching two years in age, supplied with bone meal from weaning onwards, show a normal inorganic P fraction of 5 mg. per 100 c.c. of blood. Control heifers without bone meal show 2·3 mg., or less than half. Control cows may drop to 1 mg., or even lower. Calves of control mothers are normal so long as milk supply is adequate, but may show reduced inorganic P if aphosphorosis of the mother is acute. In general, low inorganic P in the blood is associated, with poor condition of the animal. Rapid colorimetric determination of inorganic P in the blood of the grazing animal, easily obtained from the jugular vein, provides a simple means of detecting phosphorus deficiency in the pasture.Although long-continued phosphorus deficiency leads to the clinically recognisable disease “Styfsiekte,” especially in lactating animals, the less pronounced deficiency, manifested as malnutrition and stunting of growth, without direct mortality, is detected by blood analysis with equal certainty.
The determination of the volume and air space of soil clods
Authors: Russell E. W. , Balcerek W. 
Published: March 2009

A method is described for determining the field volume and the air space of a clod of any shape by filling its pores with a hydrocarbon oil, such as paraffin or tetralin, and determining its weight in the oil and in air before and after impregnation. The method appears to work well for clods of any moisture content.This method is shown to give values of these volumes entirely comparable with those given by the other accurate methods described in the literature. Its accuracy for clods of Rothamsted soil, weighing between 20 and 500 g., was probably at least 1 part per thousand, i.e. 0-1%.The method has been applied to the determination of the available water held by a soil and has been used to illustrate the effect of long-continued applications of farmyard manure to a soil in increasing the amount of available water it can hold.